A Case of Atrial Septal Defect (ASD) in a Miniature Schunauzer Dog

박철,최치봉,김일환,박희명,Park, Chul,Choi, Chi-bong,Kim, Il-hwan,Park, Hee-myung The Korean Society of Veterinary Science 2003 大韓獸醫學會誌 Vol.43 No.2

An atrial septal defect (ASD) is congenital heart disease with a communication between the atria, which allows blood to shoot from the atrium with pressure. A 3-month-old female Miniature Schunauzer was referred to the Veterinary Teaching Hospital of Konkuk University for the evaluation of systolic heart murmur. At presentation, the mucous membrane was cyanotic. On physical examination, an ejection-type systolic murmur was auscultated at the pulmonic area. In addition, thoracic radiography showed enlargement of main pulmonary artery and right atrial/ventricular enlargement. Echocardiography revealed dilated right atrium and atrial septal defect. However, mitral and tricuspid valve were still intact and well tolerating. The presence of an ASD was confirmed by identifying flow across the defect with color Doppler imaging. Doppler echocardiography provides a means of non-invasive documentation and quantification of ASD. Complete blood count and serum chemistry were not remarkable. Although large defect was confirmed between the two atrium, the patient did not show any obvious clinical signs of heart failure at this time.

P-179 : 밸브진단기를 활용한 관망시스템 내의 유지관리기술 개발

박철한 ( Chul Han Park ),이현동 ( Hyun Dong Lee ),조명훈 ( Pill Jae Kwak ),곽필재 ( Myung Hun Choi ),윤상린 ( Sang Leen Yun ),공명식 ( Myeong Sik Kong ) 한국물환경학회(구 한국수질보전학회) 2013 한국물환경학회·대한상하수도학회 공동 춘계학술발표회 Vol.2013 No.-

American cocker spaniel dog에서 발생한 삼첨판 이형성 증례

박철,최치봉,서정향,정병현,박희명,Park, Chul,Choi, Chi-Bong,Sur, Jung-Hyang,Chung, Byung-Hyun,Park, Hee-Myung 대한수의학회 2004 大韓獸醫學會誌 Vol.44 No.1

A 2-year-old, female, American cocker spaniel dog presented for a 1-year history of severe ascites, exercise intolerance, tachypnea. At that time, she was in an emergency state. First, the dog was stabilized with oxygen therapy. A diagnosis of cardiac problem was made from history, auscultation, radiograph, ECG, and echocardiography. Jugular pulsation was palpated and a harsh, systolic murmur of tricuspid regurgitation was prominent at the right cardiac apex. Tricuspid valve dysplasia (TVD) was confirmed with echocardiography, accompanying enormous myocardial hypertrophy. The clinical signs had been improved for 8 months with careful therapy and periodic abdominocentesis, and ascites was well controlled. The situation, however, became worse quickly in a week because the client did not follow our management schedule. Finally, she died due to dyspnea and shock. After the spontaneous death, necropsy and histopathological examination were performed and when we opened the thorax, a significantly large heart was observed. On histopathological findings, grossly myocardium appeared pale initially, then progressed to yellow and white. Microscopically, there was an extensive hemorrhage along with loss of myocardial striations. Interstitial fibrosis and various degenerative alterations in myocytes were also present.

리튬이온 배터리의 열관리가 전기자동차 주행거리에 미치는 영향

박철은(Chul-Eun Park),유세웅(Se-Woong Yoo),정영환(Young-Hwan Jeong),김기범(Kibum Kim) 한국산학기술학회 2017 한국산학기술학회논문지 Vol.18 No.5

전기자동차에 사용되는 리튬이온 배터리의 성능은 배터리 온도에 따라 큰 차이를 보인다. 본 논문에서는 유한차분법을 이용하여 배터리의 발열량에 따른 배터리의 온도변화를 평가하고, 배터리의 충전량, 내부저항 및 전압변화를 조사하였다.이 배터리 모델을 1차원 해석 프로그램인 AMESim과 연동하여 전기자동차가 NEDC 모드로 주행 시, 배터리의 온도 변화에 따른 전기자동차의 주행거리를 산출하였다. 배터리는 온도가 25℃ 이하로 감소하면 내부저항이 증가하기 때문에 발열량이 증가하여 주행거리는 줄었다. 또한, 배터리의 온도가 25℃ 이상이 되면, 배터리의 충전량이 감소하여 배터리의 성능이 떨어지고 그 결과로 주행거리가 줄었다. 배터리의 성능을 최적으로 유지할 수 있는 온도인 25℃를 기준으로 배터리의 온도가 -20℃와 45℃일 때, 전기자동차의 주행거리는 각각 33%와 1.8% 감소하였다. 배터리의 최적 온도를 유지하기 위해 효율적인 배터리 열관리를 통하여 저온에서는 가열, 고온에서는 냉각이 이루어져야 한다. 해석 결과 외기온이 -20℃인 경우 500 W의 열을 공급해주어야 하며, 외기온이 45℃ 경우에는 냉방을 통해 250 W의 열을 방출해줌으로써 배터리 구동의 최적 온도인 25℃를 유지할 수 있다. The performance of lithium ion batteries used in electric vehicles (EV) varies greatly depending on the battery temperature. In this paper, the finite difference method was used to evaluate the temperature change, state of charge (SOC), internal resistance, and voltage change of the battery due to heat generation in the battery. The simulation model was linked with AMESim to calculate the driving range of an EV traveling in New European Driving Cycle (NEDC) mode. As the temperature dropped below 25℃, the internal resistance of the battery increased, which increased the amount of heat generated and decreased the driving range of EV. At battery temperatures above 25℃, the driving range was also decreased due to reduced SOC that deteriorated the battery performance. The battery showed optimal performance and the driving range was maximized at 25℃. When battery temperatures of -20℃ and 45℃, the driving range of EV decreased by 33% and 1.8%, respectively. Maintaining the optimum battery temperature requires heating the battery at low temperature and cooling it down at high temperature through efficient battery thermal management. Approximately 500 W of heat should be supplied to the battery when the ambient temperature is -20℃, while 250 W of heat should be removed for the battery to be maintained at 25℃.

허구적 대상의 존재론적 특성

박철은(Chul-Eun, Park) 한국외국어대학교 철학문화연구소 2010 철학과 문화 Vol.21 No.-

허구적 대상은 존재하는가? 없다면 왜 없는가? 그리고 있다면 그것은 어떠한 것인가? 그리고 허구 대상은 지시 가능한 대상인가? 허구적 대상에 대해 묘사하는 명제들은 진리값을 갖는가? 허구적 대상을 논리적으로 다룰 수 있는가? 그것의 논리적 특징은 무엇인가? 이 질문들에 대한 러셀, 설, 라일, 파슨스, 반 인와겐, 월터스토프, 우즈, 크립키, 도넬란, 루이스 등의 상이한 답변을 소개하고 그 이론적 장, 단점을 간략하게 고찰했다. Does exist a fictional character? If it doesn't exist, why doesn't it exist? and if It is, what is it? Besides, can fictional character be referenced? Does propositions that describe fictional character have truth value? Does fictional character function logically? what it's logical feature is? I present different answers to those questions of Russell, Ryle, Parsons, van Inwagen, Wolterstorff, Woods, Kripke, Donnellan and Lewis, and consider their theoretical merits and demerits briefly.

사용자 중심의 SLA 지표 선정 방법론

박철한 ( Chul-han Park ),김상수 ( Sangsoo Kim ),인호 ( Hoh In ) 한국정보처리학회 2006 한국정보처리학회 학술대회논문집 Vol.13 No.2

IT 서비스의 안정적인 공급과 IT 서비스 품질 개선을 이루고자 하는 SLA (Service Level Agreement)에 대해 많은 연구와 시도가 지금까지 진행되어 왔다. SLA 시행에 있어서 측정 지표와 그 평가 기준 선정은 매우 중요하나, 대부분 SLA 측정 지표들은 기술관점의 항목들로 구성되어 있기 때문에, SLA 시행 결과가 사용자 중심이 아닌 서비스 제공자 중심으로 나타나고 있다. 이는 사용자의 불만족을 초래하고 서비스 제공자와의 의사 소통을 어렵게 만들고, 결국 SLA 도입 실패로 이어지는 원인이 되고 있다. 본 연구에서는 기존의 SLA 측정 지표들에서, 사용자 중심의 SLA 측정 지표로 활용할 수 있는 항목들을 BSC 의 인과관계모델을 통해 추출하고, AHP 기법을 통해 SLA 평가 기준들과 측정 지표들에 대한 가중치를 도출하였다. 이를 통하여 사용자 관점의 SLA 지표 선정 방법에 대한 명확한 기준을 제시하였다.

통신암호화에 응용된 로렌츠 기반 이산 카오스의 동기화에 관한 연구

박철,김영태,고형화,Park, Chul,Kim, Young-Tae,Ko, Hyung-Hwa 한국통신학회 1997 韓國通信學會論文誌 Vol.22 No.11

본 논문에서는 카오스 현상을 발생시키는 이산 로렌츠 시스템의 컴퓨터 모의 실험에 대한 방법을 제시하였다. 모의 실험에서의 카오스적인 움직임은 수치해석에 의해 예측된 결과와 일치하였다. 동기화된 카오스 시스템의 원리를 사용함으로써, 비화통신을 위한 접근 방법 로렌츠 방정식을 코딩한 송.수신기를 컴퓨터를 사용, 모의 실험함으로써 증명하였다. 송신기에서는 카오스 신호를 사용해서 보내고자 하는 메시지를 먼저 카오스 신호와 곱하고 다시 카오스 신호를 더해서 전송한다. 한편 수신기에서는 전송된 신호를 수신측 카오스 신호로 빼준 후에 다시 나누어서 전송된 메시지를 회복하는 방법을 사용하였다. 비선형 상태추정으로써 로렌츠 이산 카오스 동기 시스템의 견고성의 정도를 결정하기 위해서 샘플링 시간을 달리했으며, 이때 동기 오차와 그에 따른 송신신호와 수신신호와의 오차 값을 비교하여 성능을 평가하였다. In this paper, a computer simulation of the Lornz discrete chaotic system is described. The chotic behavior closely matches the results predicted by numerical simulations. Using the concept of discrete synchronized chaotic systems, the possibility of a secure communication is proved by simulating the Lorenz system in both the transmitter and receiver. In the proposed approach, at first, a chaotic modulating signal is multiplied with the message, and these are transmitted with adding a chaotic modulating signals, and then at the receiver, the chaotic modulating signal is regenerated and divided from the receiver signal. Varying a smapling time interval to calibrate the robustness of the Lorenz discrete synchronized chaotic system as a nonlinear state estimator, we measured the performance of the Lorenz discrete syncrhonized chaotic system by comparing the synchronization error and the error between transmitted signal and received signal.

아산만 해역 동-춘계 대증식기의 플랑크톤 변화

박철,이두별,이창래,양성렬,정병관,Park, Chul,Lee, Doo-Byoul,Lee, Chang-Rae,Yang, Sung-Ryull,Jung, Byoung-Gwan 한국해양학회 2008 바다 Vol.13 No.4

아산만 해역에서 2005년 2월부터 6월까지 환경 요인과 플랑크톤 군집의 변화를 파악하고 이들 간의 상관관계를 파악해 보았다. 수온은 전형적인 겨울철과 봄철의 수온양상을 보였고, 염분의 변화는 크지 않았다. 식물플랑크톤은 2월에 만의 안쪽에서 첫 번째 peak를 보인 후 5월에 만 전체적으로 두 번째 peak를 보였다. 수온의 증가는 식물플랑크톤 우점종의 천이를 유발하여 2월의 식물플랑크톤 대증식기에는 규조류가 가장 우점하였으며, 5월에는 규조류와 은편모조류가 혼재하며 발생하였고, 6월에는 와편모조류가 우점하였다. 일반적으로 연안해의 식물플랑크톤 대증식은 봄철과 가을철에 발생하는 것으로 알려져 있으나 아산만 해역에서는 이보다 약 한달 정도 빠르게 발생하는 것으로 나타났다. 또한, 식물플랑크톤 대증식시에 산염은 활발히 흡수되어 식물플랑크톤 성장에 이용되었고, 질산염은 제한 영양염으로 작용하였다. 중형동물플랑크톤은 수온과 유의한 양의 상관관계를 보였고, 식물플랑크톤과는 음의 상관관계를 보였다. 중형동물플랑크톤은 식물플랑크톤의 대증식이 발생한 $2{\sim}3$달 이후에 개체수가 증가하였다. 증가한 수온과 먹이로 인해 동물플랑크톤 군집이 성장한 것으로 해석된다. Temporal variations in plankton assemblages and environmental factors in Asan Bay and their relationships were examined with the data collected from February till early June, 2005. Seawater temperatures showed typical pattern of temporal change observed in temperate waters. Salinity variation was minor. Phytoplankton biomass showed two peaks, one in February only in the inner part of the bay and the other in May in the whole bay. Phytoplankton succession was clearly shown with the increase of seawater temperatures. Diatom (Bacillariophyceae) dominated in February, diatom and cryptomonads (Cryptophyceae) prevailed in May, and dinoflagellates (Dinophyceae) was most abundant in June. Spring bloom in Asan Bay occurred about one month earlier than those observed in temperate seas. Among the inorganic nutrients (N, P and Si), only silicate concentration showed a significant negative correlation with phytoplankton biomass, indicating the sink of this nutrient in the bay to be the uptake by phytoplankton. Nitrate concentration seemed to be a limiting factor in this bay during the study period. Mesozooplankton abundances showed a significant positive correlation with seawater temperatures and a significant negative correlation with phytoplankton biomass. Increase of mesozooplankton abundance followed phytoplankton increase with the time lag of about two months. This increase of zooplankton seemed to be the result of increased seawater temperatures and food.

아산만 요각류 Calanus sinicus 의 알 생산

박철,이평강 ( Chul Park,Pyung Gang Lee ) 한국수산과학회 1995 한국수산과학회지 Vol.28 No.1

Seasonality in biomass and egg production was investigated for Calanus sinicus, one of the major copepods in Asan Bay, Korea. Biomass of this species in this restricted embayment showed only one peak in spring, but egg production showed two peaks, spring (April and May) and fall (September). Average egg productions during the spawning seasons were 16.3 eggs/female/day (spring) and 7.6 eggs/female/day (fall) with maximum egg production of 39.0 eggs/female/day. Food concentrations in this bay measured in terms of particulate organic carbon (POC) were relatively high around the year, and correlation between egg production and POC was not significant. With the food provided sufficiently animals produced a lot of fecal pellets, but egg production was ceased after several days of experiment. From these results it was believed that egg production in this bay was influenced by food quality and feeding history rather than food concentrations. Habitat temperatures also seem to have influence on egg production from the facts that no egg was produced at extreme habitat temperatures, although the correlation between the two was not significant. In this bay, two generations with different time periods seem to progress yearly. Distribution was coupled with life cycle only at certain time of the year. During the other periods predation pressure by the higher trophic levels and shift of the centers of the distributions toward deeper outer bay seemed to be responsible for the observed distribution and egg production of this species in this bay. Comparing with the previous reports, migration of fairly long distance and continual reproduction seemed possible for this species.

연안역 동물 플랑크톤 시료의 변이: 반복 채집 및 시간별 채집의 필요성

박철,Park, Chul 한국해양학회 1989 韓國海洋學會誌 Vol.24 No.4

To examine the sample variability of zooplankton, samples were collected at two stations in the nearshore off Anhung (Chungnam, Korea), using a NORPAC net (76 Cm diameter, 0.333 mm mesh size) for two days, April 5 and 6, 1989. The net was towed vertically to eliminate the source of variation due to vertical migration. During the period of 6 hours, triplicate sampling was done every one or two hour at each station. Species composition and abundances at two stations were not so different, but the abundances at each station varied greatly with respect to sampling time. Greater abundance at one sampling time ranged 2.3-8.7 times of smaller abundance at another sampling time. At the level of ${\alpha}=0.05$, however, mean abundances of different sampling time did not differ significantly from each other due to the large variance. It was believed that the large variance was caused by the time dependent effect of patchiness of which parameters were varied with time because of sea water movement. From the variation within the triplicate samples, it was considered that the abundance data obtained from single tow were not significantly different from the data in the range of 50-200% of those from single tow. From these results, the necessity for the replicate and time dependent sampling was indicated. In the nearshore like the sampling site of this study, it seemed to be better to reduce the number of stations for the replicate and time dependent sampling though the proper sampling scheme was to be decided based on the goal of the study.