침엽수로부터 발생되는 방향성 테르펜의 배출속도 비교 연구

김조천,홍지형,강창희,선우영,김기준,임준호 한국대기환경학회 2004 한국대기환경학회지 Vol.20 No.2

In order to investigate the composition ratio and the emission rate of monoterpenes emitted from coniferous trees during summer, the enclosure chamber experiments were carried out for two tree species (Pinus densiflora and Pinus rigida). The major monoterpenes from the pine trees were α-pinene, β-pinene, myrcene and β-phellan-drene. There was no difference of the composition ratio between two sites for P. densiflora, but the difference was observed for P.rigida, Clearly, the ratio of β-pinene (26.1%) for P.rigida was higher than that of β-phellandrene (12%) at the Gumsung mountain site, but the ratio of β-phellandrene (22.2%) was higher than that of β-pinene (9.9%) at the Chiri mountain site. Particularly, the composition ratio of β-phellandrene was higher than that of β-pinene for P.densiflora, and the opposite trend was found for P.rigida at the Gumsung mountain site. The characteristics of the composition ratio between two species were similar at the Chiri mountain site. As a result of the emission rate measurements, it was observed that both sites did not show any significant β value (slope between emission rate and temperature) and ERs (Standard Emission rate at 30℃) difference. However, the β value and ERs at the Chiri mountain site were slightly greater than those of Gumsung mountain site for both pine species. P.densiflora(1.703 and 1.971㎍C/gdw/hr) showed the higher monoterpene ERs than those of P.rigida (0.572 and 0.698 ㎍C/gdw/hr) at both sites.

Computational electroencephalography analysis for characterizing brain networks

Jun-Sang Sunwoo,Kwang Su Cha,Ki-Young Jung 대한임상신경생리학회 2020 Annals of Clinical Neurophysiology Vol.22 No.2

Electroencephalography (EEG) produces time-series data of neural oscillations in the brain, and is one of the most commonly used methods for investigating both normal brain functions and brain disorders. Quantitative EEG analysis enables identification of frequencies and brain activity that are activated or impaired. With studies on the structural and functional networks of the brain, the concept of the brain as a complex network has been fundamental to understand normal brain functions and the pathophysiology of various neurological disorders. Functional connectivity is a measure of neural synchrony in the brain network that refers to the statistical interdependency between neural oscillations over time. In this review, we first discuss the basic methods of EEG analysis, including preprocessing, spectral analysis, and functional-connectivity and graph-theory measures. We then review previous EEG studies of brain network characterization in several neurological disorders, including epilepsy, Alzheimer’s disease, dementia with Lewy bodies, and idiopathic rapid eye movement sleep behavior disorder. Identifying the EEG-based network characteristics might improve the understanding of disease processes and aid the development of novel therapeutic approaches for various neurological disorders.

Sleep characteristics associated with drowsy driving

Sunwoo, Jun-Sang,Hwangbo, Young,Kim, Won-Joo,Chu, Min Kyung,Yun, Chang-Ho,Yang, Kwang Ik ELSEVIER 2017 Sleep Medicine Vol.40 No.-

<P><B>Abstract</B></P> <P><B>Objective</B></P> <P>The aim of this study was to evaluate sleep characteristics associated with drowsy driving in an adult population.</P> <P><B>Methods</B></P> <P>The study subjects consisted of 1675 adults aged 19 years or older who completed a population-based questionnaire survey on sleep habits. Experiences of drowsy driving were obtained from self-reported data. We investigated sleep-related variables including sleep duration, sleep efficiency, chronotype, subjective sleep perception, daytime sleepiness, sleep quality, and snoring. We performed multivariate logistic regression analysis to determine sleep characteristics independently associated with drowsy driving.</P> <P><B>Results</B></P> <P>The mean age of the subjects was 43.2 years, and 66.3% were men. The prevalence of self-reported drowsy driving was 23.6% (396 of 1675), and 33.1% of subjects experienced dozing at the wheel at least once a month. Multivariate analysis demonstrated that men, office and manual workers, excessive daytime sleepiness, depression, habitual snoring, and perceived insufficient sleep were independently associated with drowsy driving. Subgroup analyses revealed that reduced weekday sleep duration was a risk factor of drowsy driving in adults with perceived sufficient sleep. On the other hand, frequent alcohol drinking significantly increased risk of drowsy driving in the subgroup with perceived sleep insufficiency. Furthermore, ordinal regression analyses confirmed the association between sleep characteristics and drowsy driving across different drowsy driving frequencies.</P> <P><B>Conclusion</B></P> <P>Excessive daytime sleepiness, depression, habitual snoring, and perceived insufficient sleep were sleep-related risk factors for drowsy driving. In addition to maintaining healthy sleep habits, individuals at high risk should be encouraged to evaluate underlying sleep disorders or psychiatric problems to prevent drowsy driving.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The prevalence of self-reported drowsy driving was 23.6% in this study. </LI> <LI> Excessive sleepiness, depression, snoring, and perceived insufficient sleep were risk factors for drowsy driving. </LI> <LI> Individuals at high risk should be evaluated for underlying sleep disorders or depression. </LI> </UL> </P>

A Case of Juvenile Huntington Disease in a 6-Year-Old Boy

Sunwoo, Jun-Sang,Lee, Soon-Tae,Kim, Manho The Korean Movement Disorder Society 2010 Journal of movement disorders: official journal of Vol.3 No.2

<P>Huntington disease is a neurodegenerative disorder distinguished by the triad of dominant inheritance, choreoathetosis and dementia, usually with onset in the fourth and fifth decades. It is caused by an unstable cytosine-adenine-guanine (CAG) trinucleotide repeat expansion in the gene IT15 in locus 4p16.3. Juvenile HD that constitutes about 3% to 10% of all patients is clinically different from adult-onset form and characterized by a larger number of CAG repeats typically exceeding 60. We report a case of a 6-year-old boy with myoclonic seizure and 140 CAG repeats confirmed by molecular genetic analysis.</P>

A High-Resolution Stereo 18-Bit 4th Order Sigma-Delta D/A Converter for Digital Audio

Sunwoo,Jun,Kim,Young SaEng,Park,Sung Uk,Lee,Seong Ho,Kim,Suk Ki 대한전자공학회 1995 ICVC : International Conference on VLSI and CAD Vol.4 No.1

This paper describes an 18-bit Stereo Digital to Analog Converter(DAC) for Digital Audio equipments. The circuit consists of 2 stage, 8 tunes Digital Interpolation Filter, 128 Dines 4th Order Sigma-Delta Modulator and 1bit DAC for Pulse Density Modulation(PDM) Outputs. The interpolation filter has +/-0.0005dB Passband ripple and 110dB Stopband rejection on key specifications. The measured Dynamic Range of the DAC is 96dB and S/(N+D) is 91dB. Die size is 22.1㎟ using 0.8um standard CMOS process (single poly, double metal).

메타버스 환경에서 지식 그래프 기반 AI 챗봇을 이용한 민원 서비스 구현 및 최적화

지동준(Dong-Jun Ji),정선우(Sunwoo Jung),김민규(Min-Kyu Kim),안진현(Jinhyun Ahn),이세제(Se-Je Lee),전대성(Dae Sung Jun),임동혁(Dong-Hyuk Im) 한국산학기술학회 2023 한국산학기술학회논문지 Vol.24 No.8

자연어 처리(NLP;Natural Language Processing) 기술은 다양한 분야에서 인간의 언어를 이해하고 처리하는데 활용되고 있다. 이러한 기술은 요약, 텍스트 생성, 번역, 질의응답, 토픽 모델링 등 다양한 응용 분야에서 연구되고 있으며, 특히 챗봇에 대한 관심이 높아지고 있다. 챗봇은 인공지능 기술을 활용하여 사용자와 대화 및 상호작용을 목적으로 개발되었으며, 교육, 산업, 비지니스 등 다양한 분야에서 활용되고 있다. 하지만 기존의 챗봇 모델은 사용자의 질문에 대한 답변 제공 시 의도와 다른 답변이나 정확하지 않은 답변을 도출한다는 한계가 존재한다. 이에 지식 그래프(Knowledge Graph)를 활용하여 사용자의 질문에 대한 답변을 빠르고 정확하게 제공하기 위한 챗봇 모델을 설계했다. 기존 인터넷 민원 서비스는 상담을 위해 접수 후 7일이라는 시간 소요가 발생하는데 본 연구에서 제안된 챗봇 모델은 메타버스 가상공간 내에서 행정 민원 서비스를 처리 할 수 있도록 설계되었다. 따라서 본 연구는 특정 도메인인 행정민원 서비스에서 지식 그래프를 활용한 AI 기반 챗봇 모델의 활용 가능성을 제시한다. Natural language processing (NLP) technology is used to understand and process human language in various fields. These technologies are being studied in various applications, such as summarization, text generation, translation, question answering, topic modeling, etc. In particular, interest in chatbots is increasing. Chatbots were developed for the purpose of conversation and interaction with users using artificial intelligence (AI) technology and are used in various fields, such as education, industry, and business. However, chatbot models have had limitations in that they derive answers that are different from the intended answers or are inaccurate when providing answers to user questions. Accordingly, a chatbot model was designed to quickly and accurately provide answers to users questions by utilizing a knowledge graph. Current internet services for civil complaints take 7 days to respond after a request for consultation, but the chatbot model proposed in this study is designed to handle administrative civil complaint services within the metabus virtual space. This study suggests the possibility of using an AI-based chatbot model and a knowledge graph in the specific domain of administrative civil service.

Tocilizumab in Autoimmune Encephalitis Refractory to Rituximab: An Institutional Cohort Study

Lee, Woo-Jin,Lee, Soon-Tae,Moon, Jangsup,Sunwoo, Jun-Sang,Byun, Jung-Ick,Lim, Jung-Ah,Kim, Tae-Joon,Shin, Yong-Won,Lee, Keon-Joo,Jun, Jin-Sun,Lee, Han Sang,Kim, Soyun,Park, Kyung-Il,Jung, Keun-Hwa,Jun Springer-Verlag 2016 Neurotherapeutics Vol.13 No.4

<P>A considerable portion of autoimmune encephalitis (AE) does not respond to conventional immunotherapies and subsequently has poor outcomes. We aimed to determine the efficacy of tocilizumab, an anti-interleukin-6 antibody, in rituximab-refractory AE compared with other treatment options. From an institutional cohort of AE, 91 patients with inadequate clinical response to first-line immunotherapy and following rituximab were retrospectively reviewed. Patients were grouped according to their further immunotherapy strategies. Thirty (33.0 %) patients were included in the tocilizumab group, 31 (34.0 %) in the additional rituximab group, and 30 (33.0 %) in the observation group. Outcomes were defined as the favorable modified Rankin Scale scores (aecurrency sign2) at 1 and 2 months from the initiation of each treatment strategy and at the last follow-up. Favorable clinical response (improvement of the modified Rankin Scale scores by aeyen 2 points or achievement of the mRS scores aecurrency sign 2) at the last follow-up was also analyzed. The tocilizumab group showed more frequent favorable mRS scores at 2 months from treatment initiation and at the last follow-up compared with those at the relevant time points of the remaining groups. The majority (89.5 %) of the patients with clinical improvement at 1 month from tocilizumab treatment maintained a long-term favorable clinical response. No serious adverse effects of rituximab or tocilizumab were reported. Therefore, we suggest that tocilizumab might be a good treatment strategy for treating AE refractory to conventional immunotherapies and rituximab. The tocilizumab-mediated clinical improvement manifests as early at 1 month after treatment initiation.</P>

Unveiling the Root Cause of the Efciency‑Lifetime Trade‑Of in Blue Fluorescent Organic Light‑Emitting Diodes

Sunwoo Kang,Jun Yeob Lee,Taekyung Kim 대한금속·재료학회 2020 ELECTRONIC MATERIALS LETTERS Vol.16 No.1

The origin of efciency-lifetime trade-of in triplet–triplet fusion (TTF) type blue fuorescent organic light-emitting diodes(OLEDs) was investigated and the device structure to resolve the issue was developed. The efciency and lifetime were simultaneously improved in the blue OLEDs by developing a multilayer hole transport stack which can adjust carrier densities andrecombination zone in the emitting layer (EML). It was found that electron leakage from EML and high spatial density of excitons in the vicinity of the electron blocking layer for high TTF rates by narrow recombination zone are the detrimental factorsfor efciency-lifetime trade-of. A multilayer hole transport stack employing a deep highest occupied molecular orbital holetransport layer and an electron blocking layer combined with an appropriate hole blocking layer simultaneously improved thepower efciency by 16% at 500 cd/m2and lifetime by almost 100% (from 73 h up to 145 h). In addition, the low efciency in thelow luminance region was also completely controlled, resulting in negligible efciency variation in the entire luminance range.

Immunoglobulin G4-Related Disease Involving Various Head and Neck Regions: A Case Report

Jun Yong Im,Miok Sunwoo 대한영상의학회 2022 대한영상의학회지 Vol.83 No.4

Immunoglobulin G4 (IgG4) related disease (IgG4-RD) is currently considered an immune-mediated condition and is recognized as a disorder group with common pathological, hematological, and clinical characteristics. This disease may involve diverse organs of the head and neck, and include mainly the lacrimal gland, orbit, thyroid gland, pituitary gland, and the meninges. Here, we report a case of IgG4-RD in a 65-year-old female showing head- and neck-limited but synchronously and mainly manifesting as otalgia and facial neuritis.

Synthesis and magnetic properties of Co-substituted Ce₂Fe<SUB>14</SUB>B

Jun-Sun Hwang,Kang-Hyuk Lee,Sunwoo Lee,Sang-Im Yoo 한국자기학회 2022 한국자기학회 학술연구발표회 논문개요집 Vol.32 No.2