MTPA Tracking Control of Sensorless IPMSM Based on Pulsating Voltage Signal Injection

학위논문(박사) -- 서울대학교대학원 : 공과대학 전기·정보공학부, 2022. 8. 설승기.최근 전동기의 소형화와 출력 밀도 증가 추세에 따라 자기 포화도가 높은 매입형 영구자석 동기전동기(Interior permanent-magnet synchronous motor, IPMSM)가 개발되고 있다. IPMSM은 기저 속도(Base speed) 이하 영역 구동 시, 효율 및 최대 토크 측면에서 이점을 가지는 단위 전류 당 최대 토크 운전(Maximum torque per Ampere, MTPA)으로 동작한다. 그러므로, 자기 포화 상황에서도 높은 효율 및 출력 토크를 유지할 수 있는 실시간 MTPA 추종 운전의 필요성이 증대되고 있다. 본 논문에서는 IPMSM의 자속 모델 기반 MTPA 기술을 바탕으로 위치 센서가 없는 IPMSM에 대해서 실시간 MTPA 추종 운전을 수행한다. 제안하는 실시간 MTPA 추종 운전은 전압 정보를 통한 고정자 자속 추정 가능 여부에 따라, 중고속 영역과 저속 영역 알고리즘으로 나누어 구성된다. 중고속 영역 MTPA 추종 운전에 앞서, 본 논문에서는 임의의 좌표계에서 MTPA 운전점을 판별할 수 있는 MTPA 조건식을 제시한다. 이를 토대로 회전자 위치에 상관 없이 MTPA 운전점을 판별할 수 있는 추정 MTPA 좌표계를 제안하고 제안된 좌표계에서의 MTPA 조건을 유도한다. 추정 MTPA 좌표계의 도입을 통해 MTPA 운전점 판단에 필요한 동적 인덕턴스 정보를 4개에서 1개로 줄일 수 있다. 간소화된 MTPA 조건식을 바탕으로 중고속 영역 MTPA 추종 알고리즘을 제안한다. 제안하는 중고속 영역 알고리즘은 고정자 전압 정보에 기반한 자속 추정기, 동적 인덕턴스 추정기, MTPA 운전점 추종기로 구성된다. 본 논문에서는 고정자 자속을 추정하기 위해 주파수 적응형 자속 추정기(Frequency adaptive flux observer, FAO)를 채택했으며, FAO의 이산 시간 구현 시 발생할 수 있는 오차를 분석하여, 이산화 오류(Discretization error)에 강인한 FAO의 이산 시간 구현 방법을 제안한다. 그리고 단일 맥동 전압 주입을 통해 MTPA 조건식 계산에 필요한 동적 인덕턴스를 계산한다. 이 때, 정확한 동적 인덕턴스 추정을 위한 주입 전압각 제어기를 제안한다. 제안하는 중고속 영역 알고리즘은 운전점에 따른 인덕턴스 및 자속 참조표를 필요로 하지 않으며, 위치 센서가 부착되지 않은 IPMSM에서도 실시간으로 MTPA 운전점을 추종할 수 있다. 기울어진 맥동 전압 주입에 기반한 저속 영역 MTPA 추종 운전 알고리즘을 제안한다. 제안하는 저속 영역 알고리즘은 자속 추정기 대신 중고속 MTPA 추종 시 얻어진 인덕턴스 및 자속 정보를 바탕으로 주입 전압각을 결정하여 저속 영역에서 MTPA 운전점을 추종한다. 또한, 제안하는 저속 영역 MTPA 추종 운전의 수렴성을 보장하기 위해 IPMSM이 가져야하는 충분 조건을 제시한다. 제안하는 MTPA 추종 알고리즘은 자기 포화로 인한 제정수 변동 상황에서도 정확하게 MTPA 운전점을 추종할 수 있다. 150 kW 급 전기 자동차 견인용 IPMSM에서 최대 토크까지 제안하는 MTPA 추종 알고리즘이 성공적으로 동작하는 것을 실험적으로 검증한다.As the torque density of the interior permanent-magnet synchronous motors(IPMSMs) gets higher, the more magnetically saturated IPMSM is being developed. Below the base speed, maximum torque per Ampere(MTPA) operation is required for the high efficiency and the maximum torque capability of IPMSM. Therefore, an online MTPA tracking operation considering the magnetic saturation is required. This dissertation presents an online MTPA tracking algorithm based on the flux model of IPMSM, which can be applied to the sensorless condition. The proposed algorithm consists of two sub-algorithms; one is for the mid-and high-speed region where the stator flux can be observed from the stator voltage, and the other is for the low-speed region. Prior to the algorithm for the mid-and high-speeds, an MTPA criterion is formulated at an arbitrary reference frame. Furthermore, the estimated MTPA reference frame(EMRF) is proposed, and the MTPA criterion on that frame is derived. On the EMRF, the MTPA condition can be assessed without the rotor position information. Moreover, the proposed MTPA criterion at the EMRF requires only one inductance information, while the conventional criterion at the rotor reference frame is formulated with four inductance information. Based on the simplified MTPA criterion, an MTPA tracking algorithm for mid-and high-speeds is proposed. The proposed method comprises a flux estimator based on the stator voltage observation, a dynamic inductance estimator based on the pulsating voltage injection, and an MTPA point tracking controller. This dissertation adopts the frequency-adaptive flux observer(FAO) to estimate the stator flux information. The discretization error of the conventional implementation of FAO is analyzed. Based on the analysis, an FAO’s implementation at the synchronous reference frame, robust to the discretization error, is proposed. The dynamic inductance estimator calculates the d-axis inductance at the EMRF based on the pulsating voltage signal injection. To enhance the estimation accuracy, the injection voltage vector is dynamically changed by an injection voltage controller. The proposed mid- and high-speed algorithm does not need the preset inductance/flux look-up table and is applicable to the sensorless IPMSMs. This dissertation proposes an MTPA tracking algorithm for the low-speeds based on the tilted pulsating voltage signal injection. Instead of the real-time flux estimator, the proposed low-speed algorithm utilizes the inductance and flux information obtained in the mid-and high-speed operation, which determines the direction of the injected voltage vector. This dissertation presents a sufficient condition of IPMSM for the stable operation of the proposed low-speed algorithm. The proposed MTPA tracking algorithm can accurately calculate the MTPA operating point even under the parameter variation induced by the magnetic saturation. The performance of the proposed MTPA tracking algorithm is verified with a 150 kW-rated IPMSM for EV application.제 1장 서론 １ 1.1 연구의 배경 １ 1.2 연구의 목적 ８ 1.3 논문의 구성 １０ 제 2장 기존의 실시간 MTPA 추종 연구 １１ 2.1 이상적 전동기 모델 기반 MTPA 추종 운전 １１ 2.2 적응 제어 기법을 이용한 MTPA 추종 운전 １３ 2.3 P&O 방식의 MTPA 추종 운전 １５ 2.4 고주파 전류 주입 방식의 MTPA 추종 운전 １７ 2.5 전압 섭동을 통한 MTPA 추종 운전 ２１ 2.6 가상 신호 주입 방식의 MTPA 추종 운전 ２４ 2.7 라그랑지 승수법 기반의 MTPA 추종 운전 ２７ 2.8 센서리스 전동기에서의 MTPA 추종 운전 ２９ 제 3장 임의의 직교 좌표계에서의 MTPA 판별식 ３１ 3.1 라그랑지 승수법을 이용한 MTPA 운전점 기술[14] ３２ 3.1.1 영구자석 전동기의 모델링 ３２ 3.1.2 회전자 기준 좌표계에서의 MTPA 판별식 ３４ 3.2 MTPA판별식의 좌표계 독립성 ３９ 3.2.1 임의의 직교 좌표계에서의 동적 인덕턴스의 정의 ３９ 3.2.2 임의의 직교 좌표계에서의 MTPA 판별식 ４０ 3.3 제안하는 추정 MTPA 좌표계(m 좌표계) 상에서의 MTPA 판별식 ４２ 제 4장 신호 주입 및 자속 관측을 통한 중고속 영역 센서리스 MTPA 추종 운전 ４６ 4.1 제안하는 중고속 영역 알고리즘의 구성 ４７ 4.2 dm 축 동적 인덕턴스의 추정 ４９ 4.2.1 교차 결합 인덕턴스의 영향 ５０ 4.2.2 qm 축 가변 전압 주입을 통한 dm 축 동적 인덕턴스 추정 ５２ 4.3 고정자 자속의 추정 ５８ 4.3.1 연속 시간 영역에서의 주파수 적응 자속 관측기 분석 ５９ 4.3.2 제안하는 이산 시간 오차에 강인한 자속 추정기 [67] ６２ 4.3.2.1 PWM 전압 합성으로 인한 평균 자속과 전압 사이의 관계 ６２ 4.3.2.2 정지 좌표계 FAO의 이산화 오차 ６４ 4.3.2.3 동기 좌표계 상에서의 FAO 이산화 ６８ 4.3.3 시뮬레이션 및 실험 검증 ７４ 4.3.3.1 시뮬레이션 검증 ７４ 4.3.3.2 실험 검증 ７８ 4.3.4 추정 MTPA 좌표계 상에서의 구현 ８３ 4.4 MTPA 운전점 추종 제어 ８４ 4.4.1 제안하는 MTPA 추종 제어기의 구성 ８５ 4.4.2 전류 크기 제어기 입력의 정규화 ９１ 4.4.3 m 좌표계 위치 제어기 입력의 정규화 ９４ 4.4.4 제어기 이득 결정을 위한 고려사항 ９７ 제 5장 신호 주입을 통한 저속 영역 센서리스 MTPA 추종 운전 ９９ 5.1 제안하는 저속 영역 센서리스 MTPA 추종 운전 알고리즘의 구성 １００ 5.2 제안하는 저속 영역 MTPA 추종 운전의 동작 원리 １０３ 5.2.1 fT를 이용한 토크 추정 및 제어 １０３ 5.2.2 I_qh^m을 이용한 MTPA 위치 추종 １０４ 5.3 제안하는 저속 영역 MTPA 추종 운전의 수렴성 분석 １０８ 5.3.1 MTPA 운전점 주변에서의 국소 안정성 판별식 １０９ 5.3.2 자기 포화가 없는 저전류 영역에 대한 수렴성 분석 １１１ 5.3.3 자기 포화를 고려한 매입형 영구자석 전동기에 대한 수렴성 분석 １１６ 5.3.4 저속 영역 MTPA 운전점 추종 제어기 입력의 정규화 １２８ 5.4 저속 영역 MTPA 추종 운전을 위한 참조표 제작 １３１ 5.4.1 사전 시험을 통한 참조표 제작 １３２ 5.4.2 중고속 운전 중 실시간 참조표 갱신 １３３ 5.4.3 참조표 사전 제작이 어려운 경우의 기동 방법 １３７ 제 6장 구현 상의 고려사항 １３９ 6.1 추정 MTPA 좌표계에서의 전류 제어기의 안정성 １４１ 6.1.1 일반적인 전류 제어기의 구조 １４１ 6.1.2 회전자 기준 좌표계 기준 전류 제어 안정성 １４３ 6.1.3 추정 MTPA 좌표계 상의 전류 제어기의 안정성 １４４ 6.2 증분 인덕턴스와 고주파 인덕턴스 사이의 상관 관계 １４７ 6.2.1 실험 방법 및 조건 １４８ 6.2.2 주입 전압의 크기에 따른 인덕턴스 변화 １５３ 6.2.3 주입 전압의 주파수에 따른 인덕턴스 변화 １５５ 6.3 주입 전압 신호의 크기와 주파수 결정 １５９ 6.3.1 주입 전압 신호의 주파수 결정 시 고려 사항 １５９ 6.3.2 주입 전압 신호의 크기 결정 시 고려사항 １６１ 6.4 고주파 전류가 출력 토크에 미치는 영향 １６６ 6.5 고주파 전류로 인한 추가 손실 분석 １６７ 6.6 고정자 저항 오차의 영향 １７１ 6.6.1 고정자 저항 오차가 자속 추정에 미치는 영향 １７１ 6.6.2 고정자 저항 오차가 제안된 중고속 MTPA 추종 운전에 미치는 영향 １７２ 6.7 인버터 비선형성의 영향과 그 보상 １７４ 6.8 저속-중고속 운전 알고리즘 사이의 절환 １７７ 6.9 m 좌표계의 각속도를 이용한 전동기 속도 제어 １８０ 제 7장 시뮬레이션 및 실험 검증 １８２ 7.1 시뮬레이션 및 실험 조건 １８２ 7.2 시뮬레이션 검증 １８４ 7.2.1 시뮬레이션의 구성 １８４ 7.2.2 중고속 영역 시뮬레이션 결과 １８６ 7.2.3 저속 영역 시뮬레이션 결과 １８８ 7.2.4 고정자 저항 오차의 영향 １９１ 7.3 실험 검증 １９２ 7.3.1 실험 세트 구성 １９２ 7.3.2 중고속 영역 실험 결과 １９４ 7.3.3 저속 영역 실험 결과 ２０２ 7.3.4 중고속-저속 영역 절환 ２１２ 7.3.5 m 좌표계 각속도를 이용한 속도 제어 ２１３ 제 8장 결론 ２１６ 8.1 연구 결과 ２１６ 8.2 향후 과제 ２１９ 부 록 ２２３ 참고 문헌 ２４１ Abstract ２４７박

A Study on the Decision Making Model for Automated Container Terminal

컨테이너 터미널은 물류비 절감뿐만 아니라 환적화물의 유치로 국가와 지역경제 발전에 영향을 미친다. 컨테이너 터미널의 연관산업(물류, 금융, 무역, 배후연계산업 등)이 미치는 경제적 파급 효과가 크기 때문에 오늘날 컨테이너 터미널은 경제·산업 관문의 임무를 수행하는 필수 기간시설이 되었다. 최근 세계 경제의 저성장과 초대형 선박의 등장, 높은 인건비, 부족한 노동력에 대한 문제 해결을 위하여 자동화 도입이 급증하면서 각국의 터미널은 중심항으로 위치를 확고히 하고자 자동화 도입을 추진하고 있다. 항만환경에 대응하기 위하여 우리 정부도 『제3차 전국 항만 기본계획 수정계획(2016~2020)』 및 『제2차 신항만 건설 기본계획(2019~2040)』등과 같이 무인 자동화, 친환경 등 차세대 스마트 포트를 구축하기 위한 계획을 발표하였지만, 세계 각국의 선진 컨테이너 터미널과 비교하면 현재 국내 항만은 자동화 초기단계에 머물러있다. 본 연구에서는 이러한 환경변화에 대응하기 위한 컨테이너 터미널 자동화 개발에 앞서, 이해관계자를 중심으로 종합적인 의견을 반영하여 향후 자동화의 원활한 도입을 위한 기초자료로써 인과관계를 파악하고 시사점을 도출하고자 한다. 본 연구는 이해관계자의 의견을 반영하여 컨테이너 터미널 자동화 도입선정에 관한 인과관계 모형을 검증하기 위하여 컨테이너 터미널 자동화 및 항만선택모형 선행연구를 검토하여 요인을 도출하였다. 도출된 요인을 바탕으로 SPSS 25.0과 AMOS 21.0을 활용하여 경로모형구축, 요인분석 및 신뢰도 분석, 구조방정식 모형분석 순으로 수행하였다. 분석결과 요인분석을 통해 외생변수(비용, 생산성, 자동화 기술축적, 안전성, 서비스 향상)와 내생변수(성과향상, 만족도 향상)로 구분하였다. 구조방정식 모형분석을 통해 컨테이너 터미널 자동화 도입선정에 영향을 미치는 요인으로 생산성, 자동화 기술축적, 서비스 향상이 성과향상에 영향을 미치고 생산성은 만족도 향상에도 영향을 주는 것으로 분석되었다. 성과가 향상될수록 만족도에 영향을 주는 유의미한 결과를 도출하였다. 컨테이너 터미널 자동화의 도입을 통해 컨테이너 터미널의 생산성 향상과 기술력 확보 및 질 높은 서비스의 제공을 위한 노력이 필요하다고 판단된다. 이러한 노력을 바탕으로 향후 항만사고 건수 감소, 불특정 대기시간 감소, 효율적 자원이용, 운영비 절감, 처리 물동량 증가 등의 성과향상을 기대할 수 있을 것으로 보인다. 국내의 실정에 맞는 단계적인 자동화 도입을 통해 컨테이너 터미널을 이용하는 선사와 화주의 만족도 향상을 제고하여 글로벌 선사의 기항빈도를 높이는 등 경쟁력을 강화할 필요가 있다고 판단된다. 따라서 본 연구는 선행연구에서 다루지 않았던 컨테이너 터미널 자동화에 관련한 구조방정식 모형에 대해 분석하고자 하였으며, 향후 국내의 컨테이너 터미널 자동화 개발에 있어, 이해관계자의 종합적인 의견을 충족시킬 수 있는 개발방향 설정을 위한 기초적인 자료로 활용될 것으로 기대한다.|Container terminals affect the national and regional economic development by efficiently attracting transshipment freight. Container terminals' associated industries(Logistics, Finance, Trade, Port Hinterland, etc.) also have significant economic ripple effects, making container terminals an essential infrastructure to serve as the gateway to economic and business With the rapid increase in the construction of Automated Container Terminal, all over the world’s terminal is accelerating competition to establish its position as the Hub-port. since the world's low-growth economic has been rapid, the emergence of extra-large ships, the high labor costs, and the lack of labor force etc. In order to respond to changing ports, the Korean government also announced『The 3rd National Port Master Plan Revised Plan(2016~2020)』and『The 2nd New Port Construction Plan(2019~2040)』. It includes contents for building next-generation smart ports such as unmanned automation and eco-friendliness. Compared with the advanced container terminals in the world, domestic ports are in preparation stage. In this research, before developing the Automated Container Terminal to cope with such environmental changes, by reflecting comprehensive opinions about stakeholders centered, we will identify causal relationships and draw implications as basic data for smooth introduction of automation in the future. In order to verify the causality model of Automated Container Terminal selection based on the opinions of the container terminal stakeholders, this study examined the previous studies on container terminal automation and port selection model to derive factors. The empirical analysis was carried out in order of path model construction, factor analysis, reliability analysis, and structural equation modeling using SPSS 25.0 and AMOS 21.0 programs. As a result of the analysis, the factors were classified into exogenous variables (cost, productivity, automation technology accumulation, safety, service improvement) and endogenous variables (performance improvement, satisfaction improvement). Through structural equation modeling analysis, productivity, automation technology accumulation, and service improvement have an effect on performance improvement, and productivity has an effect on satisfaction. Also, the performance improved has a significant impact on satisfaction. In order to actively promote Automated Container Terminal, efforts are needed to improve the productivity of container terminals, secure technology, and provide high service. Based on these efforts, we expect to see improvements in performance such as reduced port accidents, reduced unspecified waiting times, efficient resource use, reduced operating costs, and increased throughput. It is necessary to improve the satisfaction of ship owners and shippers who use container terminals and increase the frequency port of call and competitiveness of global ship carriers by adopting step-by-step automation appropriate for the domestic circumstances in Korea. Therefore, this study aims to analyze the structural equation model related to Automated Container Terminal that has not been done before. According to the future development of domestic container terminal automation, It is expected to be provided as basic data for setting development direction that can satisfy the comprehensive opinions of stakeholders.제 1 장 서 론 1.1. 연구의 배경과 목적 1.2. 연구의 구성과 개요 제 2 장 컨테이너 터미널 자동화의 개요 및 현황분석 2.1. 컨테이너 터미널 자동화 정의 및 기술 2.2. 국내 컨테이너 터미널 자동화 현황 2.3. 국외 컨테이너 터미널 자동화 현황 2.4. 시사점 제 3 장 선행연구 고찰 3.1. 컨테이너 터미널 자동화 선행연구 3.2. 컨테이너 터미널 선택요인 선행연구 3.3. 설문조사 요인구성 3.4. 선행연구와의 차별성 및 시사점 제 4 장 실증분석 4.1. 분석 방법 4.2. 분석대상 및 범위 4.3. 연구모형 4.4. 분석 결과 제 5 장 결 론 5.1. 연구결과 요약 5.2. 연구의 한계점 및 향후 과제 참고문헌 부 록Maste

미술에 대한 글쓰기 - 데리다의 수행성 개념을 중심으로

학위논문 (석사)-- 서울대학교 대학원 인문대학 미학과, 2017. 8. Peter W. Milne.What does writing about art do? This thesis explores this question by reading Jacques Derridas +R, a textual response to the paintings and drawings of the artist Valerio Adami, as a performative engagement. J. L. Austins introduction of performativity in the 1950s opened a new prospect in thinking about communication: a speech, spoken or written, not only describes the given facts but also performs an act in its issuing. Derrida appreciates the notion of the performative as it allows for an understanding of communication that is not limited to transference of a unified content. Nevertheless, Derrida questions the notions underlying conditions and attempts to situate it in different terms throughout numerous oeuvres. Notably, Derrida undertakes a brief yet significant reconfiguration of the performative, and suggests a close association between the term and his writing on art, in the introductory pages to The Truth in Painting. However, as yet there has been little scrutiny on this association. I argue that Derridas understanding of the performative is a critical missing link in reaching a comprehensive grasp on Derridas art writing. +R, in particular, has been marginalized in the literature on Derridas philosophy and art criticism alike due to its enigmatic and irregular style of writing. In light of the Derridian performative, I reintroduce +R as an occasion to rethink the conventions of art criticism and to address the general question of what writing about art does. To this end, I examine first the Derridian notion of the performative. According to Derrida, the performative in Austins sense does not escape the metaphysical tradition that privileges presence over absencethe speech act theory is still rooted in dichotomies such as the serious and the non-serious or the standard and parasitical use of language, in all of which the latter is excluded. This leads Derrida to carry out a reconfiguration of the notion, which I will examine in terms of iterability, the logic of the supplement, and the production of event. In accordance with his critical perspective of Western metaphysics, Derrida argues that it is neither the present intentionality nor the exhaustibly definable context that regulates meaninginstead it is the absolute absence of, or a radical break from, the immediate context that allows a communication to take place. In this regard, iterability, the ability to be repeated in alterity, is the condition of the performative. Based on this observation, I analyze the supplementary structure of the Derridian performative to show how binary hierarchies presupposed in the orthodox speech act theory can no longer be maintained. By inscribing the infinite supplementarity to the performative and displacing the dogmatic distinctions of its original scheme, Derrida proposes an extended understanding of the performative, beyond the strict distinction between the verbal and extraverbal as well as the constative and the performative. Finally, I examine the performative production of the event by elaborating Derridas distinct understanding of the event, the inaugural power of the performative, and interpretation. As meaning is understood to be possible within the supplementary chain, production does not indicate a creation ex nihilo but rather something that takes place within an interpretation that explores limitless possibility and transforms what it interprets. Based on this analysis, I examine the performative qualities of +R. In +R, the conditions of the performative as examined in previous chapters are carefully considered and performatively demonstrated. Accordingly, it does not abide by the conventions of art criticism with a seeming disregard for dominant elements such as the presence of the artwork, the intention of the artist, and preexisting discourses. Without absolutizing any of these elements deemed essential in art writing, the performance of +R displaces and resituates the relationship between the physical attributes of the artworks and the descriptions of them, the artist and the writer, and preexisting discourses and art writing. +R does not provide a methodology or a model of art writing in the conventional sense. But it urges the writer to engage performatively with the artwork in a singular way, without relying on absolutized criteria or discourse equipped in advance to master the work.Introduction 1 Chapter 1. Preliminary Discussion: the Notion of the Performative in Austin and Derrida 9 1.1. Austins Concept of the Performative 10 1.2. Derridas Reading of Austins Speech Act Theory 19 Chapter 2. The Logic of the Supplement and the Extended Notion of the Performative 34 2.1. The Logic of the Supplement 35 2.2. The Supplementary Structure of the Performative 42 Chapter 3. Performative Production of the Event 56 3.1. The Event Made Possible by Iterability 57 3.2. The Inaugural Power of the Performative 66 3.3. The Performative Production as Interpretation 72 Chapter 4. Reading +R as Performative Engagement 77 4.1. Performatively Describing the Artwork 80 4.2. Mutual Betrayal: Adami and Derrida 84 4.3. Rethinking Discourse: To Remain Heterogeneous 89 Conclusion: Art Writing after +R 99 Bibliography 108 Illustrations 113 Abstract in Korean 114Maste

치과의사에 의해 보고된 발치 및 임프란트 수술 후 지각이상에 대한 분석

치의학과/석사[한글] 고난이도의 치과 시술이 보편화되게 됨에 따라 이에 수반되는 합병증 및 부작용에 대한 연구가 활발하게 진행되고 있다. 이 중 신경손상의 경우 지각마비 혹은 지각이상이 동반되게 되는 경우가 많고, 술자가 최선을 다해서 시술을 하게 되는 경우에도 발생되는 경우가 많으며 또한 이에 따른 주의의 의무, 결과 예견의 의무를 다하지 않는 경우 환자와 술자간의 마찰 및 불신을 형성할 수 있기 때문에 더욱 중요하다고 볼 수 있다. 그동안 신경손상에 관한 보고는 외상에 따른 하악골 골절 및 감염, 병적 소견(종양) 등에 의해서도 빈번히 발생되지만 치과시술과 연관된 것은 주로 발치에 초점을 맞추어 왔다. 특히 하치조신경의 경우 하악 제 3대구치와 해부학적으로도 근접되어 있기 때문에 하악 제 3대구치의 발치할 경우 이와 같은 신경손상이 발생할 가능성이 높으며, 최근 치과 임상에서 많이 시행되는 임프란트 시술은 매식체의 초기고정을 위해 가능한 길이가 긴 매식체의 식립이 선호됨으로 드릴링 시 하치조 신경관의 손상을 동반할 가능성이 높고 이로 인한 신경 손상의 보고가 증가되는 추세이다. 따라서 본 연구는 2004년 6월부터 8월까지 임프란트 세미나에 참석한 치과의사 중 설문조사에 응답한 276명에서 이중 발치 후 지각마비의 발생에 대한 설문조사시 지각이상을 경험한 108명, 임프란트 수술 후 지각마비의 발생에 대한 설문조사시 지각이상을 경험한 68명을 대상으로 지각이상의 위치, 동반증상, 회복율 및 회복기간에 대한 분석을 시행하여 다음과 같은 결론을 얻었다. 1. 지각마비의 발생부위는 하악 구치부에서 가장 많이 발생되었으며 이는 발치 및 임프란트 수술시 지각마비가 발생한 경우에 모두 적용되었다. 2. 발치의 경우 53.7%, 임프란트의 경우 67.6%로 지각마비 이후 관련증상(지각이상)이 발현되었으며 가장 많이 나타나는 증상은 동통이었다. 3. 지각마비 혹은 지각이상은 환자의 성별, 연령과 상관성이 적었다. 4. 지각마비 혹은 지각이상의 경우 대부분의 경우 6개월 이내에 해소되었으나 상관성은 없었다. [영문]Dysesthesia is defined as an unpleasant abnormal sensation, whether spontaneous or evoked. Reported dental causes of dysesthesia include third molar extractions, surgical molar premolar extractions, implant placement, needle trauma following block anesthesia, periapical inflammation, denture compression of the nerve and neural injury following endodontic treatment. In this questionnaire study, the subjects chosen for this study were 276 dentists who answered the questionnaire about dysesthesia after tooth extraction and implant surgery. The analysis of the results consist of the sex and age distribution, affected site, rate and duration of the recovery. The results are summarized as follows. 1. There were no significant difference between the sex and the dysesthesia. 2. In most of the cases, between the tooth extraction and implant surgery, the affected site was mandibular region; the innervation of inferior alveolar nerve. In the group of the implant surgery, 100% affected the mandibular site. The extraction group was also 93.2% affected. 3. Both of them, Pain was one of the most associated symptom with dysesthesia-46.5% of the tooth extraction and 44.8% of the implant surgery. 4. Both of them, recovery ratio was 72.3% in the tooth extraction, 71.8% in the implant surgery. Most of them they recovered in 1~6 months, 90.1% in the tooth extraction and 88.2% in the implant surgery, though statistically insignificant. Based on the data stated above, if dysethesia occurs or is suspected after the procedure, the clinician must inform the patient of its existence and various methods for monitoring recovery of sensation should be needed, not only a simple assessment but also light touch sensation, 2-point discrimination, brush stroke direction, thermal stimulation, pin prick pain sensation, and pain-pressure threshold for objective assesment of prognosis.ope

Application of ICHD-II criteria for headaches in a TMJ and orofacial pain clinic

The aim of this study was to identify and diagnose headache in a temporomandibular joint and orofacial pain clinic population using the second edition of The International Classification of Headache Disorder criteria. In 502 temporomandibular disorder and orofacial pain patients, 246 patients (49%) were diagnosed with tension-type headache (TTH), followed by migraine without aura (14.5%), probable migraine (12.9%), migraine with aura (7%), probable TTH (4.8%) and cluster headache (0.2%). The prevalence of headaches was compared between male and female patients, and the prevalence of migraine was found to be higher in women than in men. In evaluating by age, the prevalence of migraine was highest in patients in their 20s and 30s and declined as age increased above 40. TTH showed the highest rate throughout all age groups, but it also decreased as age increased. In this study, the prevalence of migraine was lower than that reported in Dr Kim et al.'s study, and the prevalence of TTH much higher than that reported in the previous study. Of the headache patients, 81.1% presented with masseter muscle pain and 47.8% with temporal muscle pain. This finding suggests that pericranial muscle pain may be an inducing factor of primary headacheope

Analysis of the Dental Hospital Patients with Atypical Odontalgia

The purpose of this study is to looks into the clinical features of AO(Atypical odontalgia) patients. to find out relationship between AO and previous dental treatments. and to gain helpful information about the diagnosis and treatment of AO patients. The subjects chosen for this study were 42 patients who had visited the Department of Oral Medicine at Yonsei University Dental Hospital and diagnosed as AO. Previous clinical records review. questionnaires review. and diagnosis and treatment investigation were done for this study. The following results were obtained: 1. AO occurs more often to the femald(69%) than to the mald(31%). The average age is 45.2 years and the average pain duration is 40 months. 2. There were 40.5% without medical history.35.7% with GI troubles and 7.1 % with psychological diseases. And only few of them have smoking and drinking habits(7.1% each). 3. The most common site of AO is Molar area(83.3%). when the patients have more than two pain sites, unilateral case(70.8%) is more frequently shown than bilateral one. 4. Considering the departments referring to the department of oral medicine. treatment related to AO. previous dental treatment history, and visiting dental departments. AO is very closely related to the Endodontic treatments. 5. 90.5% of patients have visited more than 3 dental practitioners. 6. The number of patients who have referred pain and no referred pain were similar. 59.5% of patients have spontaneous pain. And the number of patients who have severe pain and who have moderate and light pain were similar. The average period of treatment was 7.2 months. 7. The main method of diagnosis was diagnostic anesthesia(57.1%), And it was diagnosed mainly as myofascial pain and chronic peripheral trigeminal neuropathy(28.6% each), 8. The used drugs were mainly anticonvulsants(69.0%) and antidepressants (59.5%), And the effectiveness of anticonvulsants(72.4%) is better than that of antidepressants(52%). Especially, one of the anticonvulsants, Gabapentin was used very frequently(64.3%), And topical Capsaicin has a limited effect. As a result. AO can be diagnosed from the detailed reviews of the clinical records and questionnaires when there's no abnormality in the clinical or radiographic examination but the patients appeal chronic pain which is not alleviated by dental treatments. And when the patients are considered to have AO. it's better to do a conservative treatments such as anticonvulsants or antidepressants therapy than to do an irreversible treatments like an Endodontic treatments or extractionsope

Clinical Characteristics of Headache in Orofacial Pain Patients

Headache is a common disease which influences not only individually but also socially. Temporomandibular disorders(TMD) refers to pain and dysfunction within the temporomandibular joint(TMJ) and associated muscles. TMD is presented commonly, and 70% of population are found to have one or more related symptom. A number of studies have been conducted to verify the association between headache and TMD, and some authors have proposed that headache and TMD may be related. In this study, we studied the patterns of headache presented by the patients who visited the TMJ and Orofacial pain clinic. Among the patients participated in this study, tension type headache showed the highest prevalence(48.5%), followed by migraine without aura(15.0%), probable migraine(10.6%), migraine with aura(7.1%), probable tension type headache(4.8%), and other primary headaches(1.8%). The high prevalence of tension type headache may be due to the accompaniment of orofacial pain by pericranial muscle tenderness. Comparison of sex showed that the rate of migraine was higher in female than male(female to male ratio 35.8:25.3). In age analysis, the rate of migraine was high in the twenties(42.2%) and the thirties(40.0%). As the age increased, the rate of migraine decreased, and this trend was in accordance with the previous studies. The percentage of the patients who had previously received treatment was only 26.2%, and that of those who were aware of the diagnosis was merely 8.7%. Therefore, it is not common for headache patients to get treatment, however, since orofacial pain is often accompanied by headache, more systematic diagnosis as well as precise treatment would be necessary. Moreover, since TMD could induce and aggravate headache, proper evaluation and management of TMD would be essential for diagnosis and treatment of headache. In the future, more systematic and broad investigation on the influence of causative factors of TMD on headache as well as the change in headache pattern with the treatment of TMD would be required.ope

The Effect of Argon Laser on Periodontal Disease

The purpose of this study was to evaluate photothermal effect of laser, which eliminates and reduces bacteria causing periodontal disease, on treatment of periodontal disease. This study included subjects with moderate periodontitis who visited the Department of Oral Medicine, College of dentistry, Yonsei University. The subjects were divided into experimental group, where Argon laser treatment was used, and control group, where conventional subgingival curettage was used. Gingival fluids from each subject were collected prior and after 1 week of the treatment, and changes in number of bacterial colonies cultured from aerobic as well as anaerobic bacteria responsible for the periodontal disease, and changes in clinical indices related to the periodontal disease, such as plaque index, gingival index, sulcus bleeding index, were analysed. As a result, the number of bacterial colonies of aerobic and anaerobic bacteria reduced after 1 week of the treatment in both groups, especially the bacterial colonies of anaerobic bacteria which showed statistically significant reduction(p<0.1). However, there was no significant difference between the experimental group and the control group. Clinical indices including plaque index, gingival index, sulcus bleeding index were reduced after 1 week of the treatment in both groups. In the experimental group, gingival index(p<0.1) and sulcus bleeding index(p<0.01) showed significant reduction, and, in the control group, sulcus bleeding index(p<0.01) showed significant reduction. However, there were no significant differences in each indices between the two groups. The above results suggest that Argon laser could be used as a substitute of conventional subgingival curettage, or in combination with subgingival curettage which would increase the effect of the treatment. Although the possibility of clinical application of Argon laser was observed in this study, more randomized-controlled research, including acquirement of sufficient samples as well as long-termed follow up, would be necessary before clinically effective application of Argon laser.ope

The Effect of Mouthrinse containing Chitooligosaccharide, Xylitol and Zinc on Reduction of Dental plaque, Gingivitis and Halitosis.

This study reports the effect of Chito-oligosaccharide, Xylitol and Zinc on reduction of dental plaque, gingivitis and halitosis. Chilo-oligosaccharide, extracted from Chitin, is being widely used in medical field for its antibacterial effect on broad spectrum of microorganism without adverse effect on human body. Xylitol inhibits metabolism of streptococcus mutans , the main microorganism causing dental caries, and facilitates remineralization of tooth surface. Zinc, main component of a typical hydrated compound, effectively eliminates volatile sulfur compound. Through 70 healthy, non-smoking men and women of age 20s without dental caries, periodontal disease, antibiotic administration, the effectiveness of the above agents were evaluated, and the following results were obtained. Mouthrinse used in this study is free of problems arising from other chemical bactericidals, such as Chlorhexidine. It inhibits formation of dental plaque through its antibacterial action against specific microorganisms that cause dental caries, periodontal disease, plaque formation and accumulation, moreover, with the antiinflammtory effect of chitooligosaccharide, prevention as well as treatment of periodontitis is expected. For wettability of chito-oligosaccharide, it remains intraorally for a relatively long time, and since it is drinkable, it is effective at posterior region of tongue as well as paratonsilar area. Through the action of zinc, it reduces halitiosis effectively. In particular, it is alcohol free, unlike other mouthrinse which contain alcohol as preservative. Therefore, it is expected to show high efficacy as a new generation of mouthrinse.ope

Community-friendly Integrated System for Older Persons, A Shortcut to “Aging in Place” in the Upcoming Super-aged Society Burdens

Successful or health aging may not be enough of explaining all perspectives of aging-related consequences in the upcoming super-aged society. Korea has experienced a rapid decline in the traditional family structure and a soar in nuclear families or solitude. Korea sustains paradoxically dissociated delivery of health care and welfare despite a decade of policy implementation of long-term care insurance. On November 20th, 2018, to resolve these challenges, the Ministry of Health and Welfare proclaimed a comprehensive blueprint, “community-based care program for the elderly”. “Community-based care program for the elderly” is considered as a shortcut to “Aging in Place”, later life residential sustainability in the same community and a proven better living outcome compared with institutionalization. As the frontline practitioners of caring older adults, this proclamation needs more practical details of integrating health care, physical dependence, monetary status, and eventually, placement. Despite differ-ent health care system structure and preferences of patients and their caregivers between Korea and United States, current review aims at assisting Korean practitioners with understanding the all-relevant trajectories of an elderly lung-cancer surviving man in Ohio, where remains geographic mixture of rural and metropolitan characteristics.N