기계 학습을 활용한 구동 토크 예측 기반 차량 속도 프로파일 최적화

김병건,김기훈,안윤용,성지훈,최석훈,전영호,허건수 한국자동차공학회 2022 한국 자동차공학회논문집 Vol.30 No.6

A number of studies have been proposed in order to obtain the optimal vehicle speed profile for a given route based on dynamic programming(DP). In general, solving optimization problems requires a vehicle dynamics model to accurately calculate energy consumption. However, this model cannot exactly reflect the real characteristics of various vehicles because of the nonlinearity of the rolling resistance, air resistance, and gradient resistance. Therefore, this study proposes vehicle speed optimization by using a machine learning network model that is trained from actual vehicle driving data. The performance of the proposed method is verified by simulation where the driving environment is duplicated corresponding to real driving conditions. The effectiveness of the proposed optimal speed profile is evaluated by comparing with conventional cruise control driving. As a result, driving with the optimal speed profile for a given route of 27.3 km significantly reduces battery energy consumption by 8.4 %.

TV 뉴스 발화의 개입(engagement) 표현과 수용자의 뉴스에 대한 신뢰도의 상관관계

김병건 담화·인지언어학회 2018 담화·인지언어학회 학술대회 발표논문집 Vol.2018 No.4

소비자불만대응에 있어 서비스회복에 미치는 요인에 대한 연구(생명보험 불만고객을 대상으로)

김병건,문정숙 한국소비자정책교육학회 2008 소비자정책교육연구 Vol.4 No.1

본 연구는 생명보험의 소비자불만 대응시 서비스회복에 영향을 미치는 요인과 서비스 만족도와의 상관성 및 요인별 영향도를 분석하고자 시도되었다. 연구는 불만을 제기한 고객 600명을 대상으로 한 리서치 결과를 토대로 실시하였으며, 연구결과를 요약하면 다음과 같다. 첫째, 절차요인, 담당자요인 및 결과요인은 모두 만족도와 높은 正의 상관성이 있음이 확인되었다. 둘째, 서비스만족도에 영향을 미치는 주요 요인은 “처리소요시간, 담당자만족도, 불편사항해결, 경청태도, 최초연락받은시간”이며, 특히 처리신속성이 만족도에 가장 큰 영향을 미치는 것으로 조사되었다. 셋째, 고객요구사항을 받아들이지 않았더라도 신속한 처리와 담당자의 대응태도의 개선을 통해서도 충분히 만족도를 향상시킬 수 있음이 확인되었다. 이러한 연구결과를 토대로 시사점과 함께 실무에 적용할 수 있는 실천사항을 제시하였다. The main goal of this research is to verify the relationship between service satisfaction and service recovery factors. The data and analysis is based on 600 unsatisfied customers from life insurance company. There are three results are followed: First, the customer satisfaction was directly affected by procedures, service providers and results. Second, there are several reasons for the service satisfaction that lead-time for solving, satisfaction to the service provider, the result of complaints, listening attitude and first responding time. Especially, the lead-time for solving gave major influence to the customer’s satisfaction. Third, it has also confirmed that the customer satisfactions were increased by speedy procedure and improvement of the provider’s attitude even though the complaint was not solved.

내과의사가 알아야 할 두통의 진단과 치료

김병건 대한내과학회 2023 대한내과학회 춘계학술대회 Vol.2023 No.0

Prevalence and Impact of Migraine and Tension-Type Headache in Korea

김병건,주민경,이태규,김재문,이광수,정진상 대한신경과학회 2012 Journal of Clinical Neurology Vol.8 No.3

Background and Purpose The epidemiology and impact of headache disorders are only partially documented for Asian countries. We investigated the prevalence and impact of migraine and tension-type headache - which are the two most common primary headache disorders - in a Korean population. Methods A stratified random population sample of Koreans older than 19 years was selected and evaluated using a 29-item, semistructured interview. The questionnaire was designed to classify headache types according to the criteria of the International Classification of Headache Disorders, second edition, including migraine and tension-type headache. The questionnaire also included items on basic demographics such as age, gender, geographical region, education level, and income, and the impact of headache on the participant. Results Among the 1507 participants, the 1-year prevalence of all types of headaches was 61.4% (69.9% in women and 52.8% in men). The overall prevalence rates of migraine and tension-type headaches were 6.1% (9.2% in women and 2.9% in men) and 30.8% (29.3% in women and 32.2% in men), respectively. The prevalence of migraine peaked at the age of 40-49 years in women and 19-29 years in men. In contrast to migraine, the prevalence of tensiontype headache was not influenced by either age or gender. Among individuals with migraine and tension-type headache, 31.5% and 7% reported being substantially or severely impacted by headache, respectively (Headache Impact Test score =56). Overall, 13.4% of all headache sufferers reported being either substantially or severely impacted by headache. Conclusions The 1-year prevalence rates of migraine and tension-type headache in the studied Korean population were 6.1% and 30.8%, respectively. One-third of migraineurs and some individuals with tension-type headache reported being either substantially or severely impacted by headache.

어지럼 환자의 병력청취

김병건 대한평형의학회 2009 Research in Vestibular Science Vol.8 No.2

Vertigo, defined as an illusion of the movement, always indicates an imbalance within the vestibular system. The same sensation can result from lesions in such diverse locations as the inner ear, the visual-vestibular interaction centers in the brainstem and cerebellum, or the subjective sensation pathways of the thalamus or cortex. Many neuro-otological disease, such as benign paroxysmal positional vertigo, vestibular neuritis, Meniere’s disease, stroke, migraine, phobic postural vertigo etc., can cause vertigo. The peripheral and central causes of vertigo can usually be distinguished based on other features in the history, which are discussed in detail. Vertigo, defined as an illusion of the movement, always indicates an imbalance within the vestibular system. The same sensation can result from lesions in such diverse locations as the inner ear, the visual-vestibular interaction centers in the brainstem and cerebellum, or the subjective sensation pathways of the thalamus or cortex. Many neuro-otological disease, such as benign paroxysmal positional vertigo, vestibular neuritis, Meniere’s disease, stroke, migraine, phobic postural vertigo etc., can cause vertigo. The peripheral and central causes of vertigo can usually be distinguished based on other features in the history, which are discussed in detail.

정치권력 변화에 따른 ‘진보’에 대한 표상 변화에 대한 연구 - MBC 〈뉴스데스크〉를 중심으로 -

김병건 담화·인지언어학회 2019 담화·인지언어학회 학술대회 발표논문집 Vol.2019 No.4

Prevalence Rates of Primary Headache Disorders and Evaluation and Treatment Patterns Among Korean Neurologists

김병건,주민경,유수진,Grazia Dell’Agnello,Hans-Peter Hundemer,Tommaso Panni,Sara Prada Alonso,Sarah Louise Roche,한정희,조수진 대한신경과학회 2022 Journal of Clinical Neurology Vol.18 No.5

Background and Purpose Several studies have found that the prevalence of migraine is higher among healthcare professionals than in the general population. Furthermore, several investigations have suggested that the personal experiences of neurologists with migraine can influence their perception and treatment of the disease. This study assessed these relationships in Korea. Methods A survey was used to investigate the following characteristics among neurologists: 1) the prevalence rates of migraine, primary stabbing headache, and cluster headache, and 2) their perceptions of migraine and the pain severity experienced by patients, diagnosing migraine, evaluation and treatment patterns, and satisfaction and difficulties with treatment. Results The survey was completed by 442 actively practicing board-certified Korean neurologists. The self-reported lifetime prevalence rates of migraine, migraine with aura, primary stabbing headache, and cluster headache were 49.8%, 12.7%, 26.7%, and 1.4%, respectively. Few of the neurologists used a headache diary or validated scales with their patients, and approximately half were satisfied with the effectiveness of preventive medications. Significant differences were observed between neurologists who had and had not experienced migraine, regarding certain perceptions of migraine, but no differences were found between these groups in the evaluation and preventive treatment of migraine. Conclusions The high self-reported lifetime prevalence rates of migraine and other primary headache disorders among Korean neurologists may indicate that these rates are underreported in the general population, although potential population biases must be considered. From the perspective of neurologists, there is an unmet need for the proper application of headache diaries, validated scales, and effective preventive treatments for patients. While the past experiences of neurologists with migraine might not influence how they evaluate or apply preventive treatments to migraine, they may influence certain perceptions of the disease

RTLS DS-SS모뎀의 주파수 동기 알고리즘 설계

김병건,임종태,박형래,Kim, Byung-Gun,Lim, Jong-Tae,Park, Hyung-Rae 한국통신학회 2008 韓國通信學會論文誌 Vol.33 No.9a

본 논문에서는 DS-SS 방식의 ISO/IEC 24730-2 RTLS 모뎀을 위한 주파수 동기 알고리즘을 제시한다. 제시하는 주파수 동기 알고리즘은 주파수 동기 획득 모드와 주파수 동기 추적 모드로 구성되며, 주파수 동기 획득 모드는 각도 추정과 검증 과정의 두 단계 과정을 통해 이루어진다. 각도 추정에서는 타이밍 간격에 따라 세 가지 경우로 나누어 각도를 추정하고, 검증 과정에서는 추정된 세 각도간의 이론적인 연계성을 이용하여 각도의 모호성을 제거하여 효과적인 주파수 동기화가 이루어지도록 하였다. 이러한 방식으로 구성된 주파수 동기 알고리즘의 이론적 해석과 시뮬레이션을 통한 성능 분석을 토대로 제시한 주파수 동기 알고리즘의 타당성을 검증하였다. This paper presents an automatic frequency control algorithm for RTLS DS-SS modem based on the standard of ISO/IEC 24730-2. The presented automatic frequency control algorithm consists of frequency acquisition mode and frequency tracking mode, and the frequency acquisition mode is divided into the angle estimation step for frequency offset estimation and the verification step for removing the angle ambiguity. In the angle estimation step, three different sub-bit angles are estimated according to the timing intervals, then the estimates are used to re move the angle ambiguity in the verification step. The theoretical analysis and the simulation results of the proposed frequency control algorithm are presented.

니켈 페라이트 박막에서 수직 자기 이방성과 자기적 도메인의 박막 두께 의존성

김병건,도중회,정성조,신행범,조현태,차보국 한국물리학회 2016 새물리 Vol.66 No.5

Inverse spinel NiFe$_{2}$O$_{4}$ (NFO) films were prepared on (110) MgAl$_{2}$O$_{4}$ substrates by using pulsed laser deposition. The NFO films were deposited at a substrate temperature of 600 $^\circ$C and an oxygen partial pressure of 1 mTorr, and their thicknesses were in the range of 20 nm - 240 nm. As the film's thickness increased, the positon of the (440) NFO peak moved to a higher angle, implying a relaxation of the lattice strain. For 240 nm, the lattice constant of the NFO film was about 8.39 Å, which corresponded to a lattice mismatch of about 0.6% with the lattice constant of the NFO bulk. The magnetic hysteresis measurement suggested an increasing tendency of the perpendicular magnetic anisotropy with increasing film thickness. For 160 nm, the ratio of the remanent magnetization to the saturation magnetization (M$_{rem.}$/M$_{sat.}$) was maximally $\sim$0.22. The magnetic domain structure was observed by using magnetic force microscopy. The image contrast was improved with increasing film thickness, and it was the best for a film with a thickness of 160 nm. 펄스 레이저 증착법을 이용하여 역스피넬(inverse spinel) 구조를 갖는 니켈 페라이트 NiFe$_{2}$O$_{4}$(NFO)박막을 (110) MgAl$_{2}$O$_{4}$ 기판 위에 성장시켰다. 박막은 기판온도 600 $^\circ$C, 산소분압 1mTorr에서 증착되었으며, 박막의 두께는 20 nm - 240 nm 였다. 박막의 두께가 증가할수록 (440) NFO의 X선 회절 피크가 우측으로 이동하는 것을 확인하였는데, 이는 NFO 박막의 압축변형이 이완되기 때문으로 생각되었다. 두께가 240 nm 일 때, NFO 박막의 격자상수는 약 8.39 Å으로서 벌크 시료의 격자상수와 비슷하였으며 약 0.6%만의 격자 불일치를 보였다. 수직방향 자기이력곡선 측정을 통하여 박막의 두께가 증가함에 따라 수직 자기 이방성이 강해지는 경향을 확인했으며, 160 nm 일 때 잔류 자화와 포화 자화의 비(M$_{잔류자화}$/M$_{포화자화}$)가 약 0.22로 가장 컸다. 수직 방향의 자기구역 형상을 자기 힘 현미경으로 관측하였으며, 이미지의 명암은 박막의 두께가 증가함에 따라 뚜렷해지는 경향을 보였으며 두께가 160 nm일 때 가장 좋았다.