생리학적 데이터의 조합을 바탕으로 한 아동의 집중력, 기억력 예측 알고리즘

학위논문 (석사)-- 서울대학교 대학원 농업생명과학대학 농생명공학부, 2017. 8. 이기원.Good performance is regarded as important element not only in workplace but also in daily activities. Performance of the human depends on the mental capacity and mental workload. Performance declines when the mental workload exceeds mental capacity. The point the mental capacity is exceeded by mental workload is regarded to as the cognitive redline of workload. Performance declines faster at this point, as task demand is greater than the mental capacity. Few studies of the cognitive redline of workload have been done. In addition, for good performance, mental workload is regarded as more important than physical workload. Especially, according to piagets cognitive development theory, children in concrete operational stage is critical for further learning ability that they develop their ability to distinguish between quality and quantity. However, the reason that mental workload is difficult to quantify through physiological measures, makes it more complicated to demonstrate the cognitive redline. When it comes to childrens development, physical change is visible and easy to identify but mental change is not. Moreover, EEG which is one of the representative measuring tool of physiological data requires accurate process of measuring and analyzing with the expert. HRV is relatively easy to measure but has limitation because it is indirect way of measuring brain signal. Above all things, many researches of real-time indicator measuring physiological data such as heart rate variability (HRV), skin conductance response (SCR) have been done sporadically but not integrated. Therefore, In this study I tried to demonstrate if I can predict the mental capacity (attention and memory ability) not mental workload with the EEG. In addition, with the combination of EEG and HRV, I tried to overcome disadvantages of physiological tool and tried to develop advanced algorithm which predicts mental capacity. Attention ability was measured with Stroop task, and memory ability was measured with digit span task. Elementary school students aged 6-13 were participated, whose brain development is in important phase according to Piaget theory. In conclusion, right-temporal EEG data significantly predicts attention score, and occipital EEG data significantly predicts memory score. I also analyzed brain wave EEG model, and found out beta EEG power significantly predicted attention score but not memory score. I also analyzed HRV data with all other physiological data to earn more predictable algorithms model. These data can be used as daily performance parameter of attention and memory ability. However, in the further study more number of population are needed to increase the accuracy of the model. Moreover, Application which can collect and analyze physiological data needs to be more sophisticated and needs to be properly connected to wearable devices.Ⅰ. Introduction. 1 1.1. Mental capacity and mental Workload 1 1.2. Physiological measurements as a real time indicator 2 1.2.1 Physiological measurements: Electroencephalography (EEG) 4 1.2.2 Physiological measurements: Heart rate variability (HRV) 5 1.3. Limitation of current physiological researches. 6 1.4. Cognitive development in children. 8 1.5. My hypothesis . 8 Ⅱ. Materials and methods. 10 2.1. Procedures 10 2.2. Participants. 11 2.3. Physiological measurements 16 2.3.1 Resting state EEG recordings. 16 2.3.2 Heart rate variability measurement. 17 2.4. Stroop task 18 2.5. Digit Span task. 19 2.6. Data analysis 20 Ⅲ. Results 23 3.1. Most predictable attention and memory ability algorithm model based on ROI (EEG) analysis 23 3.1.1. Right temporal (F8) is the most predictable attention ability algorithm model and Addition of HRV data to attention ability algorithm increases prediction accuracy 23 3.1.2 Occipital (O2) is the most predictable memory ability algorithm model and Addition of HRV data to memory ability algorithm increases prediction accuracy. 26 3.2. Most predictable attention and memory ability algorithm model based on Brain wave (EEG) analysis. 28 3.2.1 Beta wave is the most predictable attention ability algorithm model and Addition of HRV data to attention ability algorithm increases prediction accuracy. 28 3.2.2 There was no brain wave which can predict memory ability However, with the addition of HRV data, there was increase in predictability in the model. 29 Ⅳ. Discussion 32 4.1. With the specific area (temporal, F8) and specific brainwave (beta wave), Attention can be predictable. Moreover, with the addition of HRV data, predictability increased. As a result, temporal (F8) and beta wave predicts attention mostly 32 4.2. With the specific area (occipital, O2), Memory can be predictable. Moreover, with the addition of HRV data, predictability increased. As a result, Occipital (O2) predicts attention mostly. 34 4.3. Physiological data as real-time indicator in daily life. 38 Ⅴ. References 40 Ⅵ. 국문 초록 46Maste

Research of USV for Long-term and Wide-area Oceanographic Observation

An unmanned surface vehicle(USV) for the purpose of long-time and wide-area oceanographic observation was studied. In this study, the development of real-time marine weather observation system and energy harvesting module for exploration of long time was studied. The details of the study are described as follows: 1) Development of the marine environment information collection/processing/ transmission module - Development of DAQ system for oceanographic observation - Development of algorithm for the moving oceanographic observation - Development of a remote-controlled visual monitoring and DB system 2) Development of energy recovery module for power source of marine drone - Optimal design/production of solar energy generation - Development of Battery Management System for the battery charge/ discharge and stabilization (BMS) - Develop of Power Management System for power control of marine drone (PMS) 3) Development of USV - hull linear design and production for Energy efficiency/stability - Development of autonomous driving and Dynamic Positioning System for the performable mission of oceanographic observation 4) Development of navigation algorithm - Navigation control algorithm, Composition of auto-pilot simulator 5) Performance test of the developed USV and control system목 차 List of Tables iii List of Figures iv Abstract viii 제1장 서 론 1.1 연구배경 1 1.1.1 무인해양운동체 5 1.2 연구 목표 9 1.3 논문구성 9 제2장 무인 수상선의 동력학 모델 2.1 무인 수상선의 구조 11 2.1.1 무인 수상선의 설계 12 2.1.2 무인 수상선 정유체 해석 21 2.1.3 무인 수상선 선체 저항 해석 22 2.1.4 무인 수상선 선형시험 결과 24 2.2 무인 수상선의 동력학(Dynamics) 29 2.2.1 무인 수상선의 동력학 29 2.2.2 유체력 30 2.2.3 유체력을 포함한 무인 수상선의 3자유도 운동방정식 33 2.3 무인 수상선의 운동성능 시뮬레이션 34 2.3.1 무인 수상선의 기초운동 및 제어 성능 시뮬레이션 34 제3장 무인 수상선의 전장 시스템 구성 3.1 무인 수상선의 전장 시스템 구성 38 3.1.1 무인 수상선의 추진시스템 39 3.1.2 전원관리시스템(PMS) 41 3.1.3 태양광 발전 시스템 45 3.2 무인 수상선의 해양관측시스템 49 3.2.1 해양관측시스템 구성 49 3.3 무인 수상선의 항법제어시스템 56 3.3.1 항법제어시스템 구성 56 3.3.2 무인 수상선의 항법제어시스템 60 3.3.3 무인 수상선 항법제어시스템 성능시험 66 제4장 무인 수상선의 성능 검증 4.1 무인 수상선 DP(Dynamic Position) 시험 68 4.1.1 무인수상선의 해상 테스트(운동성능 테스트) 68 4.2 무인 수상선 실해역 성능 검증 시험 70 4.2.1 무인 수상선의 실해역 성능시험 조건 70 4.2.2 무인 수상선의 성능시험 72 4.3 성능시험 결과 74 제5장 결론 78 참고문헌 81 부록 84Maste

Experimental Set Up of P300 Based Brain Computer Interface Using a Bioamplifier and BCI2000 System for Patients with Spinal Cord Injury

OBJECTIVE: Brain computer interface (BCI) is one of the most promising technologies for helping people with neurological disorders. Most current BCI systems are relatively expensive and difficult to set up. Therefore, we developed a P300-based BCI system with a cheap bioamplifier and open source software. The purpose of this study was to describe the setup process of the system and preliminary experimental results. METHODS: Ten spinal cord-injured patients were recruited. We used a sixteen-channel EEG(KT88-1016, Contec, China) and BCI2000 software (Wadsworth center, NY, USA). Subjects were asked to spell a 5-character word using the P300-based BCI system with 10 minutes of training. EEG data were acquired during the experiment. After subjects spelled the word for ten trials, the spelling accuracy and information transfer rate (ITR) were obtained in each patients. RESULTS: All subjects performed the experiment without difficulty. The mean accuracy was 59.4±22.8%. The spelling accuracy reversely correlated with the age. Younger subjects spelled with higher accuracy than older subjects (p=0.018). However, sex, injury level, time since injury and ASIA scale were not correlated with the accuracy. The mean of ITR was 2.26±1.22 bit/min. CONCLUSION: This study showed that a BCI system can be set up inexpensively with a low-price bioamplifier and open-source software. The spelling accuracy was moderately achieved with our system. P300-based BCI is useful in young patients, but modification is necessary in old patients who have low ability of recognition and concentration.ope

Feasibility of Using the Epidural Space Detecting Device (EPI-Detection TM) for Interlaminar Cervical Epidural Injection

Cervical epidural injection (CEI), which is widely used for the treatment of cervical radiculopathy, sometimes has been associated with post-operative complications. Recently, EPI-DetectionTM, which detects the negative pressure of the epidural space and notifies the proceduralist by flashing a light and producing a beeping sound, was introduced. We assumed that the newly developed device could be as safe and efficient as the conventional loss of resistance (LOR) method. Therefore, we aimed to evaluate the effectiveness of the EPI-DetectionTM and compare it to that of the conventional LOR method. We randomly assigned 57 patients to the LOR and EPI-Detection groups (29 and 28 patients, respectively). Subjects were treated with interlaminar CEI (ILCEI) using one of two methods. The measured parameters, i.e., operation time and radiation dose were lower in the EPI-DetectionTM group (4.6 ± 1.2 min vs. 6.9 ± 2.1 min; and 223.2 ± 206.7 mGy·cm2 vs. 380.3 ± 340.9 mGy·cm2, respectively; all p < 0.05) than in the LOR group. There were no complications noted in either group. Both the EPI-DetectionTM and LOR methods were safe and effective in detecting the epidural space, but the former was superior to the latter in terms of operation time and radiation exposure. The EPI-DetectionTM may help perform ILCEI safely.ope

Preoperative Cognitive Impairment as a Predictor of Postoperative Outcomes in Elderly Patients Undergoing Spinal Surgery for Degenerative Spinal Disease

Cognitive status has been reported to affect the peri-operative and post-operative outcomes of certain surgical procedures. This prospective study investigated the effect of preoperative cognitive impairment on the postoperative course of elderly patients (n = 122, >65 years), following spine surgery for degenerative spinal disease. Data on demographic characteristics, medical history, and blood analysis results were collected. Preoperative cognition was assessed using the mini-mental state examination, and patients were divided into three groups: normal cognition, mild cognitive impairment, and moderate-to-severe cognitive impairment. Discharge destinations (p = 0.014) and postoperative cardiopulmonary complications (p = 0.037) significantly differed based on the cognitive status. Operation time (p = 0.049), white blood cell count (p = 0.022), platelet count (p = 0.013), the mini-mental state examination score (p = 0.033), and the Beck Depression Inventory score (p = 0.041) were significantly associated with the length of hospital stay. Our investigation demonstrated that improved understanding of preoperative cognitive status may be helpful in surgical decision-making and postoperative care of elderly patients with degenerative spinal disease.ope

Surgical Strategies for Cervical Deformities Associated With Neuromuscular Disorders

Neuromuscular disorders (NMDs) are diseases involving the upper and lower motor neurons and muscles. In patients with NMDs, cervical spinal deformities are a very common issue; however, unlike thoracolumbar spinal deformities, few studies have investigated these disorders. The patients with NMDs have irregular spinal curvature caused by poor balance and poor coordination of their head, neck, and trunk. Particularly, cervical deformity occurs at younger age, and is known to show more rigid and severe curvature at high cervical levels. Muscular physiologic dynamic characteristics such as spasticity or dystonia combined with static structural factors such as curvature flexibility can result in deformity and often lead to traumatic spinal cord injury. In addition, postoperative complication rate is higher due to abnormal involuntary movement and muscle tone. Therefore, it is important to control abnormal involuntary movement perioperatively along with strong instrumentation for correction of deformity. Various methods such as botulinum toxin injection, physical therapy, muscle division technique, or intrathecal baclofen pump implant may help control abnormal involuntary movements and improve spinal stability. Surgical management for cervical deformities associated with NMDs requires a multidisciplinary effort and a customized strategy.ope

단일세포 RNA 시퀀싱을 이용한 사회적 계층을 조절하는 유전자 후보군 탐색

학위논문(석사) -- 서울대학교 대학원 : 의과대학 의과학과, 2024. 8. 최무림.Introduction: Social hierarchies, established through competition for resources, dictate individual behavior and social interactions within groups, offering evolutionary advantages by enhancing survival and health of an individual. Medial prefrontal cortex (mPFC) emerges as a critical neural hub in governing these social dynamics. However, genetic mechanisms underlying social status and their roles within mPFC circuits remain unknown. So, I utilized single cell RNA-seq (scRNA-seq) to analyze differences in gene expression between dominant and subordinate individuals within the mPFC neurons. Methods: Adult male C57BL/6N wild type, FosCreER, and Ai6 mice went through the tube test for social dominance. Data from 10 samples (5 for each rank) were processed using 10x Genomics Cell Ranger and Seurat package. Cell type identification was conducted using the SingleR package. Neuronal cells were isolated to find projecting mPFC neurons. Previous chromatin immunoprecipitation sequencing (ChIP-seq) studies on Pou3f1 were re-analyzed using ChIPseeker and clusterProfiler. Results: Distinct expression patterns of marker genes in the mPFC to nucleus accumbens (NAc) and the mPFC to ventral tegmental area (VTA) neurons were identified. In the subordinate mice, there was a higher expression of Nptx2, Nrn1, Cnih3, and Ankrd33b in the mPFC-NAc neurons, and a higher expression of Pou3f1 in the mPFC-VTA neurons, compared to the dominant mice. Further, Gene ontology analysis of Pou3f1 ChIP-seq data highlighted its involvement in glutamatergic synapse, synaptic membrane, and presynapse, indicating that Pou3f1 expression in the mPFC-VTA neurons may influence social competition and hierarchy through the regulation of excitatory synaptic functions in the mPFC-VTA circuit. Discussion: This study utilized the ability of scRNA-seq by providing detailed transcriptomic data at the single cell-level. Using markers of the mPFC projections, I isolated neurons projecting to the NAc or the VTA and discovered differently expressed genes (DEGs) between the dominant and subordinate mice. scRNA-seq's ability to pinpoint genes of interest represents a major advancement in understanding the genetic basis of social hierarchies. Keyword: Social hierarchy, Single cell RNA sequencing, Neuron, Brain, Behavioral genetics Student Number: 2019-25308자원 경쟁을 통해 확립된 사회적 계층은 개체의 행동 및 집단 내 사회적 상호작용을 좌우하며, 생존 및 건강을 증진시킴으로써 진화적 이점을 제공합니다. 최근 연구에 따르면 내측전전두엽(mPFC)이 이러한 사회적 계층을 형성하는 것에 관여한다는 것이 밝혀졌습니다. 그러나 사회적 지위에 따라 발현량이 달라지는 유전자(DEG)와 이들이 내측전전두엽 회로 내에서의 어떤 역할을 수행하는 지는 아직 알려지지 않았습니다. 따라서, 저는 mPFC neuron에서 서열 상위와 하위 개체 간의 발현량이 달라지는 유전자를 분석하기 위해 단일세포 RNA 시퀀싱(scRNA-seq)를 활용하였습니다. 성인 수컷 마우스들을 사회적 지배력을 평가하는 tube test를 통해 서열 상위 그룹과 하위 그룹으로 나누었고, 각 그룹 마다 5개 sample, 총 10개 sample의 데이터를 10x Genomics Cell Ranger 및 Seurat 패키지를 이용해 scRNA-seq 분석을 진행했습니다. 저는 mPFC에서 측좌핵(nucleus accumbens, NAc)으로 투사(projecting)하는 neuron 및 mPFC 에서 복측피개야(ventral tegmental area, VTA)으로 투사하는 neuron에서 marker 유전자의 발현 패턴을 확인하였습니다. 하위 그룹에서는 mPFC-NAc 뉴런에서 Nptx2, Nrn1, Cnih3, Ankrd33b의 발현이 높았으며, mPFC-VTA 뉴런에서는 Pou3f1의 발현량이 하위 그룹에서 상위 그룹에 비해 높았습니다. Pou3f1 ChIP-seq 데이터의 Gene Ontology 분석에서는 Pou3f1가 glutamatergic synapse, synaptic membrane, presynapse에 관여한다는 것을 보여주었습니다. 이는 Pou3f1의 mPFC-VTA 뉴런에서의 발현이 mPFC-VTA 회로에서 흥분성 시냅스 기능의 조절을 통해 사회적 경쟁 및 계층에 영향을 미칠 수 있음을 시사합니다. 이 연구에서 단일 세포 RNA 시퀀싱(scRNA-seq)은 사회적 계층와 관련된 DEG를 밝혀내는 데 중추적인 역할을 했습니다. 단일 세포 해상도로 전사체 데이터를 제공하는 scRNA-seq의 능력은 mPFC에서 투사하는 neruon을 나타내는 marker gene에 대한 정보를 이용하여 mPFC-NAc 또는 mPFC-VTA neuron의 표적 분리를 가능하게 했습니다. 일부 DEG는 scRT-qPCR 및 FISH 실험에서 검증되지 않았지만, 그럼에도 불구하고 실제 후보가 될 수 있는 유전자를 지목하는 scRNA-seq의 능력은 사회적 계층의 유전적 기반을 이해하는 데 있어 의미있는 진전을 가져올 수 있습니다.1. Introduction 1 1.1. Current Understanding for Social Hierarchy 1 1.2. Single Cell RNA Sequencing for Exploring Molecular Mechanism of Social Hierarchy 6 2. Methods and Materials 9 2.1. Mouse model 9 2.2. scRNA-seq Analysis 13 2.3. Pou3f1 Chromatin Immunoprecipitation Sequencing data Analysis 16 3. Results 18 3.1. scRNA-seq Reveals Hierarchy-dependent Gene Expression in Mouse mPFC 18 3.2. ChIP-seq Analysis Indicates that Pou3f1 Could Influence Social Competition and Hierarchy 39 4. Discussion 42 Bibliography 47 Abstract in Korean 52석

METHOD FOR READING ALOHA BASED TAG IN RADIO FREQUENCY IDENTIFICATION SYSTEM

본 발명은 RFID(Radio Frequency IDentification) 시스템에서의 알로하 기반(Aloha based) 태그(tag) 인식 방법에 관한 것으로, 기존에 널리 사용되는 능동 프레임 알로하 충돌방지 기법에서 한 프레임을 여러 개의 하위 프레임으로 나누어 태그가 응답하게 함으로써 태그를 인식하는데 필요한 시간을 줄이기 위한 기술에 관한 것이다. 이를 위하여 본 발명은, 모든 그룹화에 필요한 연산을 리더(reader)가 처리하고, 이를 태그에게 알려줌으로써 태그의 부하를 최소화하였다. 또한, 태그의 카운터를 사용하여 리더로부터 오는 명령을 계수함으로서 자신의 그룹과 슬롯(slotted) 순서를 태그에서 인식할 수 있게 하였다. 이를 통해 수동 RFID에서도 본 발명에 따른 그룹 알로하 충돌방지 기법을 용이하게 적용할 수 있으며, 인식 속도 또한 기존의 능동 프레임 슬롯 알로하 방식보다 향상시킬 수 있다

Are clinical outcomes affected by laminoplasty method and K-line in patients with cervical ossification of posterior longitudinal ligament? A multicenter study

Background: Open-door laminoplasty (ODL) and French-door laminoplasty (FDL) are the main laminoplasty techniques used to treat cervical ossification of the posterior longitudinal ligament (C-OPLL). However, few studies have compared the outcomes of ODL and modified FDL (mFDL) for C-OPLL. We explored the differences in outcomes between ODL and mFDL for C-OPLL and analyzed the technical efficacy of each procedure in patients with K-line (+) or (-) C-OPLL. Methods: From January 2010 to December 2015, 202 patients with K-line (+) or (-) C-OPLL were retrospectively recruited from 4 institutions. Clinical outcomes were evaluated using the Japanese Orthopaedic Association (JOA) score, JOA score recovery rate, operative time, blood loss, and complications. Univariate analysis and binary logistic regression models were adjusted for confounding factors. Results: Two hundred patients (mFDL, n = 69; ODL, n = 131) with a median follow-up of 42 months (range 36-54 months) were included. The postoperative JOA score significantly improved in both groups (P 0.05). The stratified analysis of the K-line status showed more blood loss in K-line (+) patients who underwent mFDL, but there was no significant difference in the postoperative JOA score, JOA score recovery rate, or operative time between the ODL and mFDL groups. Additionally, there was no significant difference in blood loss, postoperative JOA score, JOA score recovery rate, or operative time among all patients with K-line (+) or (-) C-OPLL in both groups. Conclusions: Both ODL and mFDL are effective for patients with C-OPLL. However, more blood loss tends to occur during mFDL. This study showed no significant difference in the operative time or incidence of complications between the two techniques. The efficacy of ODL and mFDL was not affected by the K-line status (+ or -) in patients with C-OPLL.ope