Temporomandibular Disorders during or after Dental Implant Treatment

Purpose: Temporomandibular disorders (TMD) may occur during or after regular dental treatment. The aim of this study is to suggest management of TMD involved in dental implant treatment. Materials and Methods: We investgated the etiology, site of implantation, symptoms, treatments and improvements with a focus on TMD among patients who complained of TMD symptoms during or after dental implant treatment. Results: A total of 19 patients complained of TMD associated with implant treatment. Thirteen patients complained of masticatory muscle pain, 13 patients complained of temporomandibular joint (TMJ) pain, and 8 patients complained of both masticatory muscle pain and TMJ pain. The patients were treated primarily with counselling, medication and physical therapy, and secondarily with occlusal splint therapy. Six patients received only primary treatment, and their average recovery time was 4.2 months. Four patients received secondary treatment, and their average recovery time was 8.5 months. None of the patients underwent surgical intervention of the TMJ. Conclusion: Patients who have a risk of developing TMD may experience TMD symptoms during or after implant treatment, such as facial pain, masticatory myalgia, TMJ pain and mouth opening limitation. To mitigate these symptoms, we suggest the application of the usual treatment protocols for TMD.ope

Large-eddy simulation of turbulent flow around a heavy vehicle

DoctorTurbulent flow around a 1:8 scaled realistic heavy vehicle model is studied using large-eddy simulation to understand the effect of coherent vortical structures on aerodynamic drag, lift and side force. Detailed analysis of unsteady features of the flow field and turbulence statistics has been performed while effects of drag reduction devices on flow characteristics are investigated. The dominant frequency of drag and lift, Sr=0.322 is found to be in good agreement with the pressure variation at the frontal area of the vehicle container. The frequency, which is slightly higher than the Strouhal number corresponding to the truck length, is identified as a subharmonic of the frequency at the truck base. Results of the present study suggest that the two frequencies can be employed for designing an active flow control device to alleviate aerodynamic drag and instability.본 연구에서는 1:8 비율로 축소된 실제적 형상을 갖는 화물차 주변의 고유한 와류 구조가 항력, 양력 및 측력에 미치는 영향을 알아보기 위하여 큰에디모사를 수행하였다. 큰에디모사를 통해 얻어진 유동장의 비정상 특성 및 난류 통계에 대한 분석이 수행되었으며, 항력 저감 장치가 유동장의 특성에 미치는 영향 또한 연구되었다. 항력 및 양력의 지배적인 주파수 Sr=0.322는 차량 컨테이너 전면 영역의 압력 변화와 잘 부합하는 것으로 나타났으며, 트럭 길이에 해당하는 Strouhal 수보다 약간 높은 주파수는 트럭 베이스에서 주파수의 하위 고조파로 식별되었다. 본 연구에서 도출된 이러한 두 가지 주파수는 공기역학적 항력과 불안정성을 완화하기 위한 능동적 공기저항 저감 장치를 설계하는 데 사용될 수 있을 것으로 기대된다

Efficient Link Scheduling Based on Estimated Number of Packets in Queue on Industrial Wireless Sensor Networks

The links of low power wireless sensor networks are error prone and the transmission on a wireless link is determined probabilistically by the packet reception rate (PRR) of the link. On the other hand, there is a very strict requirement in the end-to-end reliability and delay of sensor data in industrial wireless sensor networks (IWSNs). The existing approaches to provide the end-to-end reliability in IWSNs is retransmitting the packet when failure occurs. These approaches transmit a packet multiple times in successive time slots to provide the required reliability. These approaches, however, can increase the average delay of packets and the number of packets buffered in a queue. This paper proposes a new scheme to estimate the probabilistic amount of packets, called queue level (QL), in the buffer of each node based on the PRRs of the wireless links. This paper also proposes a QL-based centralized scheduling algorithm to assign time slots efficiently in TDMA-based IWSNs. The proposed scheduling algorithm gives higher priority to the nodes with higher QL. By assigning time slots first to the node with the highest QL, we can reduce the average end-to-end delay of packets and reduce the amount of buffered packets in the queue while satisfying the required end-to-end reliability. The performance of the proposed scheduling algorithm have been evaluated through a simulation using the Cooja simulator and compared with the existing approach. In the simulation on an sample network with the target end-to-end reliability of 99%, all of the flows were shown to guarantee the target reliability in both algorithms: on average, 99.76% in the proposed algorithm and 99.85% in the existing approach. On the other hand, the proposed algorithm showed much better performance than the existing approach in terms of the average end-to-end delay of packets (about 47% less) and the number of maximally buffered packets in the queue of each node (maximally, more than 90% less)

Call Control Model of Intelligent Network over B-ISDN for Multimedia Services

음성, 화상 등 여러 미디어를 포함하는 멀티미디어 서비스가 통신 사업자들에게 차세대 서비스로 많은 관심의 대상이 되고 있다. 멀티미디어 서비스들은 크고 다양한 대역폭과 복잡한 형태의 호와 서비스 제어를 요구하느데, 이러한 대역폭에 대한 요구는 ATM에 기반을 둔 B-ISDN 망에서 제공할 수 있을 것이며 복잡한 서비스는 지능망을 이용하면 용이하게 제어될 수 있다. 현재의 지능망은 전화망과 협대역 ISDN (N-ISDN)에 기반을 두고 있는데, 전달망이 B-ISDN으로 진화하게 되면 이에 맞게 지능망의 구조도 변화해야 한다. 또한 다양한 형태의 멀티미디어 서비스에서 서로 다른 특성을 갖는 단말기를 사용할 수 있도록 B-ISDN 망은 코드 변환기나 다자간 회의를 위한 회의 브리지 (conference bridge)와 같은 자원을 사용자에 투명하게 제공할 수 있어야 한다. 본 논문에서는 B-ISDN 신호의 요구 사항과 사용자에 투명한 자원 제공을 위한 지능망과 B-ISDN의 결합 방법에 대해 제안한다. 자원의 제어 기능을 B-ISDN 신호 방식과 지능망을 이용할 경우 각각에 대한 호 모델을 제시하고, 지능망을 이용하여 자원을 제어할 경우의 호 제어 모델에 대해 기술한다. 또한 차세대 멀티미디어 서비스들 중에서 가장 가까운 장래에 많이 도입 되리라고 예상되는 주문형 비디오 서비스를 제안된 호 모델과 제어 모델을 이용하여 서비스하는 서비스 시나리오에 대해 기술한다.Network service providers have been interested in the multimedia services that consist of multimedia streams including voice and image. Multimedia services require a huge amount of network bandwidth and complex control for call and services. B-ISDN based on ATM suffices the requirement of large bandwidth and IN(Intelligent Network) can deal with effectively the complex control of multimedia services. Currently IN is based on POTS(Plain Old Telephone Service) and N-ISDN, but the functional architecture of IN has to be modified according to the evolution of the underlying transmission network from N-ISDN to B-ISDN. B-ISDN must also support user transparently the resources such as code converters or conference bridges in order to be able to deploy various terminals with different attributes. This paper proposes a method for integrating IN and B-ISDN in order to satisfy the requirement of B-ISDN signaling and to provide resources user transparently. This paper proposes and compares two call models where the resources are controlled by B-ISDN signaling or IN, respectively, and proposes a call control model based on the IN. This paper also suggests various service senarios of video on demand services based on the proposed IN model.Network service providers have been interested in the multimedia services that consist of multimedia streams including voice and image. Multimedia services require a huge amount of network bandwidth and complex control for call and services. B-ISDN based on ATM suffices the requirement of large bandwidth and IN(Intelligent Network) can deal with effectively the complex control of multimedia services. Currently IN is based on POTS(Plain Old Telephone Service) and N-ISDN, but the functional architecture of IN has to be modified according to the evolution of the underlying transmission network from N-ISDN to B-ISDN. B-ISDN must also support user transparently the resources such as code converters or conference bridges in order to be able to deploy various terminals with different attributes. This paper proposes a method for integrating IN and B-ISDN in order to satisfy the requirement of B-ISDN signaling and to provide resources user transparently. This paper proposes and compares two call models where the resources are controlled by B-ISDN signaling or IN, respectively, and proposes a call control model based on the IN. This paper also suggests various service senarios of video on demand services based on the proposed IN model

난류유동의 외재필터 큰에디모사를 위한 가환성 귀납필터 개발

2

A Study on the Integration of Network Management Systems Based on CORBA

통신망이 커지고 복잡해짐에 따라 통신망 관리는 더욱 중요해지고 있다. 이러한 통신망을 효율적으로 관리하기 위해 국제 표준화 그룹인 ITU와 ISO는 CMIS/CMIP 기반의 OSI망 관리 모델 [1]을 표준화하고 IAB에서는 SNMP [7] 기반 망관리 모델을 표준화하였다. 이들 망관리 모델은 통신망 요소들의 관리에는 효율적이지만 복잡한 망들의 관리나 서비스 관리에는 많은 문제들이 있다. 이러한 문제들을 해결하기 위해 본 논문에서는 분산 객체 지향 기술인 CORBA[3]를 이용하여 기존의 망관리 시스템들을 통합하기 위한 방법에 대해 기술한다. CORBA 기반 통합 망관리 구조를 제시하고 CORBA와 OSI망관리 모델사이의 관리정보 및 관리기능 변환 기능을 위한 CORBA/CMIP 게이트웨이 구조를 제시한다. 또한 COBRA 관리자에서 OSI객체들을 접근하기 위햔 기법과 OSI객체에서 발생하는 이벤트를 CORBA 관리자에 전달하기 위한 기법들에 대해 기술한다.Network management systems become more important as the communications networks evolve larger and more complicated. For the efficient management of the communications networks, the international standard organizations, ITU and ISO, have standardized OSI network management model [1] based on CMIS/CMIP, and IAB has proposed SNMP [7]as the Internet management model. The traditional management models are efficient in managing simple communications netwrks, but have many problems in managing complicated networks and services. To solve those problems, this paper proposes an integration method of network management systems based on CORBA [3] which is a distributed and object-oriented technology. We describe an integrated network management architecture based on CORBA/CMIP gateway. The CORBA/CMIP gateway converts the management systems. We also describe how the CORBA managers access the OSI managed objects and how the events occurred in the OSI managed objects are delivered to the CORBA managers.Network management systems become more important as the communications networks evolve larger and more complicated. For the efficient management of the communications networks, the international standard organizations, ITU and ISO, have standardized OSI network management model [1] based on CMIS/CMIP, and IAB has proposed SNMP [7]as the Internet management model. The traditional management models are efficient in managing simple communications netwrks, but have many problems in managing complicated networks and services. To solve those problems, this paper proposes an integration method of network management systems based on CORBA [3] which is a distributed and object-oriented technology. We describe an integrated network management architecture based on CORBA/CMIP gateway. The CORBA/CMIP gateway converts the management systems. We also describe how the CORBA managers access the OSI managed objects and how the events occurred in the OSI managed objects are delivered to the CORBA managers