• Journal of the Korean Statistical Society
• /
• v.6 no.2
• /
• pp.167-177
• /
• 1977

유전적 질환이 있는 가계에서 출생하는 자녀중에서 유전적인 질환을 보유할 수 있는 확률을 예측하는 방법의 하나로서 우도추정치(likelihood estimator)를 사용하는 것은 분리분석(segregation analysis)에서 중요한 역할을 하고 있다. Elston과 Stewart(1971)는 이러한 분석방법의 일반적인 통계모형을 정립하였으며 필자(1974)와 Morton 등 (1974)은 complex segregation이 될 때에 분석되는 4가지의 통계모형을 주장하였다. 본 연구의 목적은 multiple ascertainment $\pi$가 존재하는 경우 분리확률모수(segregation parameter) $\theta$의 우도추정치를 구하고 둘째로 oligogenic case에 대한 이론적인 배경을 구명하고자 한다.

• 한국벤처창업학회:학술대회논문집
• /
• 2022.11a
• /
• pp.195-199
• /
• 2022

본 연구는 스타트업 투자성과와 연계된 창업가 역량, 재무정보 등 정량데이터를 기반으로 스타트업 투자자들의 투자결정요인을 분석하였다. 주요 실증결과는 다음과 같다. 첫째, 창업 초기 종업원 수가 많고, 최고경영자의 지분비율이 높을수록 투자승인 확률이 높게 나타났다. 둘째, 재무적 특성에서는 기업의 매출액 규모가 작을수록 투자승인 확률이 높게 나타났다. 이러한 결과는 스타트업의 경우, 기업의 단기성과보다는 투자 결정에 있어 미래가치 혹은 다른 정성적인 요인이 더 고려된다는 점을 보여준다. 셋째, 창업가 특성에서는 CEO 교육수준(학력)이 높을수록 투자승인 확률이 높게 나타났다. 즉, 창업자의 학력은 성공적인 투자 여부에 핵심적인 변수이고 이것은 선행연구의 결과와 다르지 않았다. 또한, 학력과 투자유치의 연관성은 창업 3년 미만 스타트업에서 상대적으로 강하게 나타났다. 선행연구에서 투자정보공개, 관련 데이터 확보의 어려움으로 스타트업 투자에 관한 정량적 실증연구가 거의 진행되지 못한 점을 고려한다면, 본 연구는 설문조사 방식을 뛰어넘어 국내 초기 창업기업만을 대상으로 성공적인 투자유치와 연계된 스타트업의 평가요인을 정량적으로 분석했다는 점에서 중요한 의의를 갖는다.

• Proceedings of the Korean Statistical Society Conference
• /
• 2000.11a
• /
• pp.45-50
• /
• 2000

Hedayat et al.(1988)와 Stufken(1993) 등은 환경 또는 생태의 특성을 고려하여 인접단위들을 추출확률을 최소화시킬 수 있는 표본설계방법을 제안하였다. 그리고 Hedayat et al.(1998)은 실제 조사에 있어 이들 방법보다 유용한 방법을 제시하였다. 본 논문에서는 이들 표본설계방법의 문제점들을 밝히고 이를 보완할 수 있는 방법과 추가적인 연구 방향 등을 제시한다.

• Proceedings of the Korean Institute of Industrial Safety Conference
• /
• 2003.05a
• /
• pp.60-66
• /
• 2003

우리 생활 주변에 도로들이 일년 내내 파헤쳐 굴착되고 있어 교통도보 등 위험을 초래하고 특히 도심교통 유발요인이 되고 있음을 매체를 통해 접하게 된다. 이들 중 대부분은 배관공사 즉 가스배관, 수도배관, 하수도배관, 송유관 등 주요기반 공사에 해당된다. 역시 사고발생이 적지 않음을 알 수 있다.(중략)

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.25 no.5
• /
• pp.317-326
• /
• 2013

Probabilistic design methods can consider uncertainties of design variables and are widely used in the design of vertical breakwaters. The probabilistic design methods include a partial safety factor method, reliabilitybased design method, and performance-based design method. Especially the performance-based design method calculates the accumulated sliding distance during the lifetime of the breakwater or during a design storm. Recently a time-dependent performance-based design method has been developed based on the first-passage probability of individual sliding distance during a design storm. However, because the allowable criteria in the first-passage probability method are not established, the stability of structures cannot be quantitatively evaluated. In this study, the allowable first-passage probabilities for two limit states are proposed by calculating the first-passage probabilities for the cross-sections designed with various water depths and characteristics of extreme wave height distributions. The allowable first-passage probabilities are proposed as 5% and 1%, respectively, for the repairable limit state (allowable individual sliding distance of 0.03 m) and ultimate limit state (allowable individual sliding distance of 0.1 m). The proposed criteria are applied to the evaluation of the effect of wave-height increase due to climate change on the stability of the breakwater.

• Journal of the Korean GEO-environmental Society
• /
• v.18 no.3
• /
• pp.31-38
• /
• 2017

The purpose of this study is to propose a chart that can easily estimate the seismic failure probability of small and medium sized earthfill dams with little geotechnical information. By considering the existing method and procedure for estimating the seismic failure probability of a dam, the zero seismic failure probability curve, on which the seismic probability is zero regardless of the geotechnical properties of the dam, was determined in the form of hyperbola in the dam height and freeboard ratio plane. It was confirmed that the dam height-freeboard ratio distribution pattern of the Korean small and medium sized dams was shaped like a hyperbola like the zero seismic failure probability curve. Therefore, a estimation chart was constructed in which a number of seismic failure probability contours are represented by a number of hyperbolas at regular intervals in the dam height-freeboard ratio plane. The proposed chart was applied to the calculation of the seismic failure probability of two small and midium sized dams with relatively well-managed geotechnical properties and the validity of the chart was confirmed by comparison with the results obtained by the existing procedures and methods. In the future, the proposed chart is expected to be useful in considering investment priorities for maintenance and reinforcement of small and medium sized dams in preparation for earthquakes.

• The Korean Journal of Applied Statistics
• /
• v.23 no.6
• /
• pp.1201-1208
• /
• 2010

In teaching probability and statistics classes, we should increase efforts to develop examples that enhance teaching methodology in delivering more meaningful knowledge to students. Sports is one field that provides a variety of examples and World Cup Soccer events are a treasure house of many interesting problems. Teaching, using examples from this field, is an effective way to enhance the interest of students in probability and statistics because World Cup Soccer is a matter of national interest. In this paper, we have suggested several examples pertaining to counting the number of cases and computing probabilities. These examples are related to many issues such as possible scenarios in the preliminary round, victory points necessary for each participant to advance to the second round, and the issue of grouping teams. Based on a simulation using a statistical model, we have proposed a logical method for computing the probabilities of proceeding to the second round and winning the championship for each participant in the 2010 South Africa World Cup.

• The Journal of Engineering Geology
• /
• v.21 no.3
• /
• pp.247-257
• /
• 2011

In this study the infinite slope model, one of the physical landslide models has been suggested to evaluate the susceptibility of the landslide. However, applying the infinite slope model in regional study area can be difficult or impossible because of the difficulties in obtaining and processing of large spatial data sets. With limited site investigation data, uncertainties were inevitably involved with. Therefore, the probabilistic analysis method such as Monte Carlo simulation and the GIS based infinite slope stability model have been used to evaluate the probability of failure. The proposed approach has been applied to practical example. The study area in Boeun area been selected since the area has been experienced tremendous amount of landslide occurrence. The geometric characteristics of the slope and the mechanical properties of soils like to friction angle and cohesion were obtained. In addition, coefficient of variation (COV) values in the uncertain parameters were varied from 10% to 30% in order to evaluate the effect of the uncertainty. The analysis results showed that the probabilistic analysis method can reduce the effect of uncertainty involved in input parameters.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.17 no.1
• /
• pp.42-54
• /
• 2018

This study is to establish the traffic volume-based warrants of left-turn lanes in unsignalized intersections based on a risk probability methodology. This study applied a risk probability of a potential rear-end collision between a left-turn vehicle and the immediately following through vehicle. With the shifted negative exponential model and the compound probability theorem, the risk probability can be expressed as the function of directional volumes, opposing volumes and the percentage of left-turns for a two-lane and four-land highway, respectively. The warrants of installing left-turn lanes on unsignalized intersections were developed with the risk probability. The warrants define the total approaching and opposing volumes to encourage a left-turn lane as a function of operating speed, percentage of left-turn, and number of lanes.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.38A no.8
• /
• pp.629-637
• /
• 2013

Chaos communication systems have the characteristics such as non-periodic, wide-band, non-predictability of signals and easy implementation. There have been many studies about chaos communication systems because of these advantages. But, chaos communication systems have low BER(Bit Error Rate) compare to general digital communication system. Existing researches on chaos communication systems only analyze BER performance according to various chaos maps. There are no studies on analysis of BER performance according to PDF(Probability Density Function) of chaos maps. In this paper, we analyze the BER performance according to changing parameter, equation, and initial values of chaos map's PDF. In addition, we propose new chaos map to improve BER performance. Simulation results show that BER performance of CDSK(Correlation Delay Shift Keying) is changed when PDF of chaos map changed. And the proposed chaos map has a better BER performance compare to previous chaos maps such as Tent map, Logistic map, and Henon map.