압축비 조절기구가 부착된 단기통 디젤엔진에 대한 BDF의 적용

박형도 ( Hyung Do Park ),양협 ( Hyup Yang ) 대한설비관리학회 2009 대한설비관리학회지 Vol.14 No.2

An experimental study on engine performance parameters and emission gas characteristics for bio-diesel fuels (BDF`s) was performed by using of a specific engine; the type of single-cylinder, four-stroke, water-cooled diesel engine with variable compression ratio adjustment mechanism (the model Farryman A 30 marine, TQ, UK). Specific fuel consumptions (SFC) and soot tendency (smoke %) for various fuel and/or operation conditions were also examined. The BDF`s used were prepared BD 20 and BD 100 together with the commercial diesel fuel (DF) for reference. The established conditions for experiment were 12:1, 14:1, 16:1 and 18:1 for compression ratio (CR), and 1000, 1500, 2000 and 2500 rpm for engine speed. It was found that SFC of BDF`s is increased 1.3~3.7% compared with DF according to the rpm`s; for the smoke %, BDF`s value is reduced significantly up to max. 45.7 % in comparison to that of DF; and while NOx is increased amazingly up to max. 38%, which is too much than the previous results of around 12.0 %. Also, it does not seem that the engine`s power output remains changed significantly according to the fuels used.

연성개폐 지붕구조물 Erection 시공법에 관한 사례 연구

박금성,김형도,곽명근,Park, Keum-Sung,Kim, Hyung-Do,Kwak, Myong-Keun 한국공간구조학회 2016 한국공간구조학회지 Vol.16 No.4

Lifting plan in the large spacial structure is an important factor influencing the efficiency and economy of the construction process. The purpose of this study was deriving the requirements for lifting techniques as the basic research in the double spoke wheel roof structure construction. In the lift up erection method, management plan of the interference error in the column and outer-ring was needed that occur during lifting roof structure. In the bent erection method, material usage reduction plan was required by the structural design of the temporary bent. In the hybrid erection method, lifting plan was needed that minimizes weather condition and crane usage. All lifting techniques were required Value Engineering model for reduction of cost and construction period.

멀티콥터를 이용한 수직방향 DTV 신호 레벨 측정

박형도(Hyung-Do Park),임솔(Sol Lim),김대진(Dae Jin Kim) 한국방송·미디어공학회 2014 방송공학회논문지 Vol.19 No.3

저산소성 뇌손상으로 오인된 비경련성 발작 지속증상

박형은(Hyung-Eun Park),조현지(Hyun-Ji Cho),김영도(Young-Do Kim) 대한임상노인의학회 2012 대한임상노인의학회지 Vol.13 No.4

Epileptic activity can cause regional vasogenic/cytotoxic edema that reflects hemodynamic and metabolic changes. However, extensive hemispheric involvements on magnetic resonance imaging (MRI) after status epilepticus (SE) were very rare. A 63-year-old man admitted to our hospital due to semicoma mental status duration about 10 hours. He had respiratory difficulty, so that he needs to care ventilator. MRI on 6th hospital day showed extensive high signal intensities on diffusion-weighted MRI (DWI) in both hemispheres resembling hypoxic brain lesions. Whereas, EEG showed epileptic discharges associated with generalized slowing waves. Follow-up MRI on 14th hospital day showed regression of previous brain lesions. Therefore, he was diagnosed as decreased mental status due to SE. This case reminded us that post-ictal MRI of SE might be ischemic lesion mimic. Therefore, we should consider DWI of cytotoxic edema after SE. 간질발작은 혈류역학성과 대사성 변화를 반영하는 혈관성/세포독성 부종의 원인이 될 수 있다. 하지만 발작지속증상이후에 광범위한 뇌실질의 변화를 뇌자기공명사진에서 보이는 경우는 매우 드물다. 63세 남자환자가 약 10시간 정도의 반혼수 상태로 내원하였다. 내원 6일째 찍은 뇌확산강조영상에서 저산소성 뇌손상과 비슷한 소견을 보였고, 뇌파에서는 전반적인 서파를 동반한 간질양파소견을 보였다. 내원 14일째 추적검사한 뇌자기공명사진상에서는 이전의 확산강조영상의 병변이 사라진 소견을 보였다. 따라서 발작후 뇌자기공명사진 소견은 저산소성 뇌손상과 같은 뇌병변 소견을 보일 수 있으므로 드물지라도 발작지속증상후 변화의 가능성도 고려해야 하겠다.

우리나라 제조업체의 교대작업실태와 교대작업여부에 따른 상병결근 및 이직에 관한 연구

박정선,백도명,이기범,이경용,이관형,Park, Jung-Sun,Paek, Do-Myung,Lee, Ki-Beom,Rhee, Kyung-Yong,Yi, Kwan-Hyung 대한예방의학회 1994 Journal of Preventive Medicine and Public Health Vol.27 No.3

In order to provide necessary information for better health of workers through understanding the actual status of the industries adopting shift systems. The data were gathered from a stratified random sample of 347 (0.5%) firms selected out of about 70,000 manufacturing industries throughout the nation in 1993. Stratification during sampling was by industrial group and number of workers. The major findings obtained from 288 firms surveyed completely were as follows : 1. About 20.2% of the 288 firms were adopting shift systems and shirtworkers accounted for about 25.1% of the total work force in 288 firms. 2. The bigger number of workers was, the higher the adopting rate of shift system was. 3. The rate of having welfare facilities such as dining room, commuting bus, washing facilities, and health care room etc. was higher in the industries adopting shift systems. 4. The major industrial groups adopting shift systems were the rubber a: plastic goods manufacturing industry (54.1 per 100 firms) and the textile manufacturing industry (44.8 per 100 firms). However, the proportion of shiftworkers was higher in the textile manufacturing industry (70.5 per 100 firms) and the electronics industry (57.9 per 100 frms). 5. The most predominant work schedule was the weekly rotating, semi-continuos 2-crew 2-shift system (47.5%). 6. In the industries adopting shift systems, shiftworkers had an adjusted average of 0.29 spells per 100 workers ($0.14{\sim}0.45$ in 95% C.I.) compared to 0.23 spells per 100 nonshift dayworkers ($0.15{\sim}0.31$ in 95% C.I.) for 1 month. 7. Also, in the industries adopting shift systems, the adjusted average annuel turn-over rate of shiftworkers was 13.07 per 100 workers ($12.03{\sim}14.12$ in 95% C.I.) compared to 10.18 per 100 nonshift dayworkers ($9.53{\sim}10.82$ in 95% C.I.).

다(多)출력 DC-DC 플라이백 컨버터용 변압기 설계방법 및 개발

박종연,강도형,Park, Jong Yeon,Kang, Do Hyung 강원대학교 산업기술연구소 2000 産業技術硏究 Vol.20 No.1

This paper gives a fundamental study of the design method of Flyback Transformer(FBT) in the Multioutput Flyback DC-DC Converter. We explained a winding strategy and Core selecting of the Flyback transformer to get the design guidelines for optimizing the performance of Flyback DC-DC Converter. The final goal of this paper is to obtain design rules of the Flyback transformer to minimize the leakage inductance for good quality of DC Souce.

온라인 커뮤니티 이용자의 잠복 관찰(Lurking) 행위 의도에 관한 연구

박도형(Park, Do-Hyung) 경희사이버대학교 미래고등교육연구소 2012 사이버사회문화 Vol.3 No.2

기존 연구의 대부분은 온라인 커뮤니티의 이용 의도에 관한 연구인데, 대부분의 연구는 이용 의도를 커뮤니티 사용 의도로 접근하였다. 하지만 커뮤니티에 참여하여 글을 쓰고 구성원간의 상호작용 없이, 단순히 커뮤니티를 방문하고, 다른 사람들의 글만 보고 정보를 얻어가는 행위(Lurking)는 온라인 커뮤니티의 발전을 저해할 수 있다. 이에 본 연구는 Preece, Nonnecke와 Andrews(2004)의 탐색적 연구를 바탕으로 온라인 커뮤니티에서 사람들이 잠복 관찰(Lurking) 하려는 행위 의도를 갖는 이유에 대해 알아보고자 한다. 기존의 온라인 커뮤니티 연구와 온라인 환경에서의 이용자 행위를 바라본 연구들을 기초로 온라인 커뮤니티의 구성원들의 행위에 영향을 줄 수 있는 요인들을 확인하고, 각 요인들이 온라인 커뮤니티내 글을 쓰는 의도와 글을 읽는 의도에 어떤 영향을 미치는지 분석하였다. 이를 통해 잠복관찰자(Lurker)들이 잠복 관찰(Lurking) 행위를 전략적으로 하려는 욕구에는 무엇이 있으며, 이런 욕구의 해결을 잠복 관찰(Lurking)이 아닌 다른 방향을 통해 해결할 수 있는 전략적 대안을 제시하였다. Online communities is getting more popular with the development of information technology. It is essential that community members participate actively and share their contents or opinions continuously for the success and growth of online communities. However, it is revealed that most of members just take the role of passive observer. They are lurking community information and contents without any contribution. In this sense, this study focuses on explore lurking behavior of online community members. Based on technology acceptance model, this study investigates the effect of two distinctive motivations(intrinsic and extrinsic motivation) on the intention for posting and reading. Finally, this study proposes several strategies to enhance information and contents sharing in online communities.

위암의 최소침습수술

박도중(Do Joong Park),안상훈(Sang Hoon Ahn),김형호(Hyung-Ho Kim) 대한종양외과학회 2015 Korean Journal of Clinical Oncology Vol.11 No.2

Gastric cancer surgery with curative intent comprises subtotal or total gastrectomy with radical lymph node dissection. Recently, as the incidence of early gastric cancer (EGC) is increasing, minimally invasive surgery can be applied to gastric cancer treatment. Minimally invasive gastric surgery has four aspects such as minimally invasive access, modified function-preserving gastrectomy, limited lymphadenectomy, and no reconstruction. Laparoscopic gastrectomy became popular for EGC and its indication is being expanded to advanced gastric cancer. Reduced or single port gastrectomy can be performed for selective EGC. For middle or upper EGC, laparoscopic pylorus-preserving gastrectomy or proximal gastrectomy is applicable as function-preserving gastrectomy. D1+ node dissection is enough for EGC without lymph node metastasis and sentinel node biopsy will be helpful for avoiding unnecessary lymph node dissection in EGC patients.

지능형 시뮬레이션 모형을 기반으로 한 정보기술 투자 성과 요인 및 전략 도출에 관한 연구

박도형(Do-Hyung Park) 한국지능정보시스템학회 2013 지능정보연구 Vol.19 No.1

Information technology is a critical resource necessary for any company hoping to support and realize its strategic goals, which contribute to growth promotion and sustainable development. The selection of information technology and its strategic use are imperative for the enhanced performance of every aspect of company management, leading a wide range of companies to have invested continuously in information technology. Despite researchers managers, and policy makers’ keen interest in how information technology contributes to organizational performance, there is uncertainty and debate about the result of information technology investment. In other words, researchers and managers cannot easily identify the independent factors that can impact the investment performance of information technology. This is mainly owing to the fact that many factors, ranging from the internal components of a company, strategies, and external customers, are interconnected with the investment performance of information technology. Using an agent-based simulation technique, this research extracts factors expected to affect investment performance on information technology, simplifies the analyses of their relationship with economic modeling, and examines the performance dependent on changes in the factors. In terms of economic modeling, I expand the model that highlights the way in which product quality moderates the relationship between information technology investments and economic performance (Thatcher and Pingry, 2004) by considering the cost of information technology investment and the demand creation resulting from product quality enhancement. For quality-enhancement and its consequences for demand creation, I apply the concept of information quality and decision-maker quality (Raghunathan, 1999). This concept implies that the investment on information technology improves the quality of information, which, in turn, improves decision quality and performance, thus enhancing the level of product or service quality. Additionally, I consider the effect of word of mouth among consumers, which creates new demand for a product or service through the information diffusion effect. This demand creation is analyzed with an agent-based simulation model that is widely used for network analyses. Results show that the investment on information technology enhances the quality of a company’s product or service, which indirectly affects the economic performance of that company, particularly with regard to factors such as consumer surplus, company profit, and company productivity. Specifically, when a company makes its initial investment in information technology, the resultant increase in the quality of a company’s product or service immediately has a positive effect on consumer surplus, but the investment cost has a negative effect on company productivity and profit. As time goes by, the enhancement of the quality of that company’s product or service creates new consumer demand through the information diffusion effect. Finally, the new demand positively affect the company’s profit and productivity. In terms of the investment strategy for information technology, this study’s results also reveal that the selection of information technology needs to be based on analysis of service and the network effect of customers, and demonstrate that information technology implementation should fit into the company’s business strategy. Specifically, if a company seeks the short-term enhancement of company performance, it needs to have a one-shot strategy(making a large investment at one time). On the other hand, if a company seeks a long-term sustainable profit structure, it needs to have a split strategy(making several small investment at different times). The findings from this study make several contributions to the literature. In terms of methodology, the study integrates both economic modeling and simulation technique in order to overcome the limitations of each methodology

여행자 관심 기반 스마트 여행 수요 예측 모형 개발: 웹검색 트래픽 정보를 중심으로

박도형 ( Park Do-hyung ) 한국정보시스템학회 2017 情報시스템硏究 Vol.26 No.3

Purpose Recently, there has been an increase in attempts to analyze social phenomena, consumption trends, and consumption behavior through a vast amount of customer data such as web search traffic information and social buzz information in various fields such as flu prediction and real estate price prediction. Internet portal service providers such as google and naver are disclosing web search traffic information of online users as services such as google trends and naver trends. Academic and industry are paying attention to research on information search behavior and utilization of online users based on the web search traffic information. Although there are many studies predicting social phenomena, consumption trends, political polls, etc. based on web search traffic information, it is hard to find the research to explain and predict tourism demand and establish tourism policy using it. In this study, we try to use web search traffic information to explain the tourism demand for major cities in Gangwon-do, the representative tourist area in Korea, and to develop a nowcasting model for the demand. Design/methodology/approach In the first step, the literature review on travel demand and web search traffic was conducted in parallel in two directions. In the second stage, we conducted a qualitative research to confirm the information retrieval behavior of the traveler. In the next step, we extracted the representative tourist cities of Gangwon-do and confirmed which keywords were used for the search. In the fourth step, we collected tourist demand data to be used as a dependent variable and collected web search traffic information of each keyword to be used as an independent variable. In the fifth step, we set up a time series benchmark model, and added the web search traffic information to this model to confirm whether the prediction model improved. In the last stage, we analyze the prediction models that are finally selected as optimal and confirm whether the influence of the keywords on the prediction of travel demand. Findings This study has developed a tourism demand forecasting model of Gangwon-do, a representative tourist destination in Korea, by expanding and applying web search traffic information to tourism demand forecasting. We compared the existing time series model with the benchmarking model and confirmed the superiority of the proposed model. In addition, this study also confirms that web search traffic information has a positive correlation with travel demand and precedes it by one or two months, thereby asserting its suitability as a prediction model. Furthermore, by deriving search keywords that have a significant effect on tourism demand forecast for each city, representative characteristics of each region can be selected.