• 대한수학회보
• /
• 제48권4호
• /
• pp.791-812
• /
• 2011

This is a survey on American options. An American option allows its owner the privilege of early exercise, whereas a European option can be exercised only at expiration. Because of this early exercise privilege American option pricing involves an optimal stopping problem; the price of an American option is given as a free boundary value problem associated with a Black-Scholes type partial differential equation. Up until now there is no simple closed-form solution to the problem, but there have been a variety of approaches which contribute to the understanding of the properties of the price and the early exercise boundary. These approaches typically provide numerical or approximate analytic methods to find the price and the boundary. Topics included in this survey are early approaches(trees, finite difference schemes, and quasi-analytic methods), an analytic method of lines and randomization, a homotopy method, analytic approximation of early exercise boundaries, Monte Carlo methods, and relatively recent topics such as model uncertainty, backward stochastic differential equations, and real options. We also provide open problems whose answers are expected to contribute to American option pricing.

• 한국지반공학회지:지반
• /
• 제7권2호
• /
• pp.27-40
• /
• 1991

동아대학교 승학캠퍼스는 산지를 굴착하여 약 10년 전부터 연차적으로 건설되어 왔다. 1989년 8월에 내린 200mm16ay이상의 집중호우로 인한 지하수 및 산사태로써 건물, 사면, 미로 등 많은 피해를 입었다. 이 피해의 원인조사 및 보완대책을 위하여 현황 및 50m 격자형 위치측량, 예비조사, 야외간이 측량법, 지구 물리학적 탐사법, 시추조사 및 흙의 특성시험 등이 수행되었다. 이러한 조사결과를 바탕으로 피해의 원인 및 예측을 수행하였으며 수평배수공법, 위험한 노출암괴의 제거, 지하배수를 겸한 옹벽설치, 붕적층의 제거 및 격자형 블록에 의한 사면안정공법 등좌 보완대책이 수립되었다.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
• /
• 제24권2호
• /
• pp.7-14
• /
• 2018

Purpose: The outbreak of Middle East Respiratory Syndrome(MERS) in KOREA has brought up the demands for ventilation guideline and regulations for healthcare facilities since most of the infection was spreaded inside healthcare facility. Currently KOREA has no ventilation guideline or regulations covering entire section of healthcare facility. The purpose of this study is to investigate current ventilation methods in KOREA healthcare facilities to in future, propose ventilation guideline. Methods: Research of foreign counties ventilation guideline and regulation for healthcare facilities were conducted for reference. Field investigation with survey of 21 healthcare were conducted to identify the ventilation system and operating methods. Additionally survey for healthcare workers were conducted to observe the recognition related to ventilation system in healthcare facility. Results: The result showed that most of foreign countries ventilation guideline and regulation suggests similar items to reduce the spread of infection and maintain good indoor air quality. The investigation results indicated that fixed guideline for ventilation in healthcare facility were required due to different ventilation operating methods. Survey result of healthcare workers has told us that ventilation guideline and regulation is needed to prevent further infection. Implications: Absence of ventilation guideline and regulations for healthcare facility in KOREA is an urgent issue.

• 한국수산과학회지
• /
• 제49권6호
• /
• pp.856-861
• /
• 2016

This study compared the density of fish determined using three different echogram methods: the frequency-difference, time variable, and threshold modification methods. An acoustic survey was conducted off the coast of Jeju Island after sunset. Data at 38 and 120 kHz frequencies were collected using a commercial fishing vessel. As a reference point, the value of ${\Delta}MVBS_{120-38kHz}$ that distinguished fish from zooplankton using the 38 and 120 kHz frequencies was set at < 2 dB. The estimated density of fish along the survey line was 0.1-30.4, 0.1-64.3, and $0.1-51.7m^2/nmi^2$ using the frequency difference, time variable threshold, and threshold modification methods, respectively. The results of this study constitute basic research for estimating fish densities.

• 대한수학교육학회지:학교수학
• /
• 제5권3호
• /
• pp.275-295
• /
• 2003

본 논문에서는 교수·학습 방법을 중심으로 우리 나라 초등학교 수학교육의 실제를 이해하기 위하여, 선행 연구 고찰, 설문 조사, 수업 관찰 등을 실시하고 그 결과를 분석하였다. 본 연구의 결과, 초등학교 수학과에서 널리 활용하는 교수·학습 방법은 강의법(또는 발문 중심의 방법), 활동 중심의 방법, 소집단 협동 학습 방법, 공학적 도구 활용 방법인 것으로 나타났다. 본 연구에서 교수·학습 방법과 관련하여 가장 미흡한 것으로 분석된 점은, 교사들이 추구하고 있는 교수·학습 방법이 다소간은 외형적인 충실함에 치중하는 경향이 있다는 것이다. 그러므로, 어떤 특정한 교수·학습 방법을 활용하여 수업을 진행한다고 할 때, 그 방법의 절차적인 순서와 같은 외형적인 측면과 함께, 그 교수·학습 방법에서 본질적으로 목적으로 하고 있는 부분이 무엇인가를 파악하고 그것을 실현하기 위해 노력할 필요가 있다.

• 한국임상수의학회지
• /
• 제15권1호
• /
• pp.222-227
• /
• 1998

This survey was based on the data of one hundred four dogs with 108 case,T of fracture admitted to the veterinary teaching hospital, College of Veterinary Medicine, Kyungpook National University and 24 private small animal hospitals from January, 1995 to Decemberi 1996. The results were analyzed as following criteria; the distribution of fractures causes of fractured age and sexual distributions month of the most frequencel total body weights presence of communicating external wound, extent of damaged direction of fracture line, location of fracture liner fracture managements fixations methods, fixations methods according to location of fracture. The results of survey were as follow: 1. Main distribution of fracture; radius . ulna (23.1%).2. Causes of fracture; road toraffic accident (39.4 T,). 3. Age; over 24 months (27.9%). 4. Sex; male (53.89)), female (46.2%). 5. Month of the most frequence; July (14.4%) 6. Total body weight: 2-5 kg (45.27)). 7. Presence of communicating external wound; closed fracture (94.2%). 8. Extent of damage; complete fracture (92.6%). 9. Direction of fracture line: comminuted fracture (27.8 To). 10. Location of fracture line; diaphysis (62.0%). 11. Fracture management; open reduction (58.3% ). 12. Fixation methods; not treat (22.2%). 13. Fixation methods according to location of fracture; radius ulna-Kirschner wire fixation (45.5%), femur. shaft-intramedullary pinning (71.4%), pelvis-bone plate (53.3%), metacarpus-not treat, Kirschner wire fixation (each 30.8%).

• 방사성폐기물학회지
• /
• 제21권1호
• /
• pp.95-114
• /
• 2023

During the decades after the Fukushima Daiichi Nuclear Power Station (FDNPS) accident, ambient dose rates have markedly decreased when compared to those at the early state of the accident. Government projects have been continuously conducted by surveying the ambient dose rate and radiocesium distributions. Airborne surveys using crewed helicopters and unmanned aerial vehicles (UAVs) are the best methods for obtaining an overall picture of the distribution. However, ground-based surveys are required for accurate measurements near the population. The differences between these methods include the knowledge of the post depositional behavior of radionuclides in land use. The survey results form the basis for policy decisions such as lifting evacuation zones, decontamination, and other countermeasures. These surveys contain crucial findings regarding post-accident responses. This paper reviews the survey methods of government projects and current situation around the FDNPS. The visualization methods and databases of ambient dose rates are also reviewed to provide information to the population.

• 한국산업안전학회:학술대회논문집
• /
• 한국안전학회 1998년도 춘계 학술논문발표회 논문집
• /
• pp.207-214
• /
• 1998

In the past several years, accident frequency rate was decreased but severity rate was increased at construction sites with less than two-hundred workers. Accidents caused by failure of education in respect with the management occupied about 40 % in 1997. In this research, a questionnaire survey to know the effects of safety education was committed for small & medium construction sites. Survey results showed that workers wanted to improve work environments and safety facilities than safety education, however they also were not satisfied to educational facilities, contents and methods. Whereas, they agreed that they improved safety consciousness after safety education. As a result, four appropriate methods to promote effective safety education were proposed.

• 한국경영과학회:학술대회논문집
• /
• 대한산업공학회/한국경영과학회 1994년도 춘계공동학술대회논문집; 창원대학교; 08월 09일 Apr. 1994
• /
• pp.112-121
• /
• 1994

Studies on visual fatigues were activated after VDTs were rapidly introduced into the office works in 1980s. Various measurement methods and its measures were developed from those studies. Early studies frequently used simple measures such as near point of accommodation, near point of vergence, and CFF. Current researches focus on dark focus, dark vergence, and VEP which have a good relevance to the visual fatigues. In spite of the merit they also have some limits and disagreements. This survey summarizes the measures, measurement methods and relevant researches. Finally several topics are proposed for the future researches in Korea.

• Journal of the Korean Data and Information Science Society
• /
• 제17권1호
• /
• pp.173-185
• /
• 2006

In this paper, we propose two methods for setting initial weights in the PLS algorithm which is employed to measure the customer satisfaction in SEM. Using data from the survey of the students conducted with the questionnaire of the ACSI survey, we evaluate the education service in terms of the satisfaction level of the students and compare our proposed methods with the previous method.