• Journal of Acupuncture Research
• /
• v.21 no.1
• /
• pp.211-225
• /
• 2004

목적 : 류마티스 관절염 환자의 골 파괴에 중요한 역할을 하는 것으로 알려진 Matrix Metalloproteinase-1(MMP-1) 유전자의 단일 염기 다형성을 분석하고, 나아가 봉독약침 치료에 대한 반응과의 연관성을 조사하기 위하여 본 연구를 시행하였다. 방법 : 미국류마티스학회의 류마티스 관절염 기준에 해당하는 122명의 한국인 류마티스 관절염 환자와 건강한 92명의 대조군을 대상으로 pyrosequencing 방법을 이용하여 MMP-1 유전자의 -519 위치의 다형성을 비교 분석하였으며, 류마티스 관절염 환자군을 다시 유전자 유형에 따라 동통 관절수, 종창 관절수, 조기 강직, 통증 강도, 삶의 질 평가도구인 HAQ, 환자 및 의사의 전반적 질병상태 평가, ESR, CRP 등의 항목을 치료 전후 평가하여 비교 분석하였다. 결과 : 1. 류마티스 환자군과 건강한 대조군간에 MMP-1 유전자의 단일 염기 다형성의 유전자형의 분포와 대립유전자 발현 빈도에 통계적으로 유의한 차이가 나타났으며, 이는 MMP-1 유전자 다형성이 한국인 류마티스 관절염 환자의 질병 감수성과 관련이 있음을 추정할 수 있다. 2. 각 유전자형 그룹간 치료전 질병의 중증도 평가에서 임상 평가와 혈액의 급성 염증 반응물질 평가에서 통계적으로 유의한 차이는 없었다. 3. 급성 염증 반응의 지표인 ESR과 CRP level의 봉독약침 치료 전후 변화는 MMP-1의 유전자 다형성과 유의한 연관이 없었다. 4. 각 유전자형 그룹간의 치료 전후 질병 호전도 비교에서, AA 유전자형이 종창 관절수 평가에서 더나은 호전을 보였으며, 다른 모든 평가에서는 통계적으로 유의한 차이가 없었으며, 향후 관련 유전자와의 연관성 연구가 필요하다고 사료된다.

• The Korean Journal of Applied Statistics
• /
• v.29 no.6
• /
• pp.1095-1106
• /
• 2016

The quantile regression method proposed by Koenker et al. (1978) focuses on conditional quantiles given by independent variables, and analyzes the relationship between response variable and independent variables at the given quantile. Considering the linear programming used for the estimation of quantile regression coefficients, the model fitting job might be difficult when large data are introduced for analysis. Therefore, dimension reduction (or variable selection) could be a good solution for the quantile regression of large data sets. Regression tree methods are applied to a variable selection for quantile regression in this paper. Real data of Korea Baseball Organization (KBO) players are analyzed following the variable selection approach based on the regression tree. Analysis result shows that a few important variables are selected, which are also meaningful for the given quantiles of salary data of the baseball players.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.20 no.1
• /
• pp.33-40
• /
• 2016

In this study, using the Cost Prediction Model and Performance Prediction Model have developed a way to estimate future management costs and performance for bridge and tunnel by Network Level. Studies to date have primarily focused on the single facility, it is difficult to apply to the analysis of the Network Level. This study, items used as an index of 'Special Act for the Safety Control of Public Structures' was added to Usability and Functionality to Status. Action period and annual budget for each facility can be estimated through the Basic and Advanced analysis. In addition, we verified the technical feasibility through case analysis.

• Journal of Korean Society of Forest Science
• /
• v.79 no.3
• /
• pp.231-244
• /
• 1990

As the complexity of society increases, the demand for the forest-based recreational site is also increased. This, in turn. makes congestion an ubiquitous type of externality in forest-based recreational site. Efficient resource allocation requires this congestion effect to be accounted and considered in the decision making process. In this content, this study was conducted to suggest a process which can be used to measure the congestion and determine the optimal number of users. Willigness to pay(WTP) function obtained from Book Han San National Park users suggested that every 20.000 users increased decrease the satisfaction of users obtained from the site visit be 27.3%. For the purpose of demonstration this WTP function is applied tit determine the optimal number of users which is estimated as about 73,000 persons per day.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.27 no.3
• /
• pp.449-457
• /
• 2017

In this paper, we analyze the security and performance of the Quantis Quantum random number generator in terms of cryptography through experiments. The Quantis' post-processing is designed to output full-entropy via bit-matrix-vector multiplication based on mathematical background, and we used the min-entropy estimating test of NIST SP 800-90B so as to verify whether the output is full-entropy. Quantis minimizes the effect on the random bit rate by using an optimization technique for bit-matrix-vector multiplication, and compared the performance to conditioning functions of NIST SP 800-90B by measuring the random bit rate. Also, we have distinguished what is in Quantis' post-processing to the standard model of NIST in USA and BSI in Germany, and in case of applying Quantis to cryptographic systems in accordance with the CMVP standard, it is recommended to use the output of Quantis as the seed of the approved DRBG.

• Journal of the Korea Convergence Society
• /
• v.10 no.11
• /
• pp.71-77
• /
• 2019

This paper defines a multi-selection knapsack problem and presents an algorithm for seeking its optimal solution. Multi-selection means that all members of the particular group be selected or excluded. Our branch-and-bound algorithm introduces a simplex containing the feasible region of the original problem to exploit the fact that the most tightly underestimating function on the simplex is linear. In bounding operation, the subproblem defined over the candidate simplex is minimized. During the branching process the candidate simplex is splitted into two one-less dimensional subsimplices by being projected onto two hyperplanes. The approach of this paper can be applied to solving the global minimization problems under various types of the knapsack constraints.

• Korea Real Estate Review
• /
• v.28 no.3
• /
• pp.21-35
• /
• 2018

The recent performance of residential mortgages demonstrated how default risk operated separately from prepayment risk. In this study, we investigated the determinants of the borrowers' decisions pertaining to early termination through default from the mortgage performance data released by Freddie Mac, involving securitized mortgage loans from January 2011 to September 2013. We estimated a Cox-type, proportional hazard model with a single risk on fundamental factors associated with default options for individual mortgages. We proposed a mortgage default model that included two specifications of delinquency: one using a delinquency binary variable, while the other using a delinquency probability. We also compared the results obtained from two specifications with respect to goodness-of-fit proposed in the spirit of Vuong (1989) in both overlapping and nested models' cases. We found that a model with our proposed delinquency probability variable showed a statistically significant advantage compared to a benchmark model with delinquency dummy variables. We performed a default prediction power test based on the method proposed in Shumway (2001), and found a much stronger performance from the proposed model.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2015.05a
• /
• pp.264-264
• /
• 2015

최근 기후변화는 우리 삶에 다양한 영향을 미치고 있으며, 이에 따른 수문순환 변화 역시 자명하게 받아들이고 있다. 이에 따라 수자원 취약성 평가 및 대책에 관한 연구는 다양하게 진행되고 있는 실정이다. 하지만 국내의 경우 전체 유역에 대한 수자원 취약성 평가 연구는 부족한 실정이다. 따라서 본 연구에서는 국내 총 12 수계인 한강, 안성천, 금강, 삽교천, 영산강, 섬진강, 탐진강, 만경강, 동진강, 낙동강, 태화강, 형산강 유역에 대한 수자원 취약성 평가를 실시하였다. 평가 방법으로는 장기간에 걸친 다양한 토양의 특징, 토지이용, 관리상태의 변화에 따른 크고 복잡한 유역의 유출량을 추정하기 위해 개발된 SWAT(Soil and Water Assessment Tool) 모형을 이용하여 수문 모형을 구축하였고, 유출 관련 매개변수 최적화 작업은 SWAT-CUP 모형을 이용하였다. 최적화된 매개변수의 적용을 통해 각 유역별 유출량을 산정하였다. 그 결과 2009년과 2011년은 한강, 낙동강, 금강, 영산강순 이였으며, 2010년은 낙동강, 한강, 금강, 영산강순 이였다. 면적별 유출량인 비유량(specific discharge)을 산정한 결과, 2009년에는 영산강, 낙동강, 금강, 한강순 이며, 2010년에는 영산강, 금강, 낙동강, 한강순 이였으며, 2011년에는 금강, 한강, 영산강, 낙동강 순을 보였다. 또한, 인구당 유출량 산정 결과 2009년에는 영산강, 금강, 낙동강, 한강순 이며, 2010년에는 영산강, 금강, 낙동강, 한강순 이며, 2011년에는 영산강, 금강, 낙동강, 한강순 이었다. 이를 바탕으로 국내 총 12 수계에 대한 수자원 취약성을 산정해보았다. 대응변수는 이수의 수요 및 공급적인 측면에서 구분하였으며, 사회/경제, 물 이용, 환경, SWAT으로 구성하였습니다. 수자원 취약성 평가를 위해 다기준의사결정기법(MCDM, Multi-Criteria Decision Making) 중 하나인 TOPSIS(Technique for Order of Preference by Similarity to Ideal Solution)기법을 사용하였다. 산정 결과 삽교천, 동진강, 형산강, 안성천, 섬진강, 만경강, 낙동강, 영산강, 태화강, 금강, 한강, 탐진강 순 이였다. 본 연구 결과는 향후 다중 공간에 구축한 고해상도 모형을 통해 국내 수문상황 진단 및 고해상도 미래 수문 시나리오 생산을 통한 수자원 관리에도 활용될 전망이며, 기후변화 취약성 평가를 위한 지표 개발에 이용될 예정이다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2019.11a
• /
• pp.264-264
• /
• 2019

The purpose of this paper is to establish development concepts for a novel collision avoidance system with preventing function of navigator's human error (Hu-CAS) in ship control behaviors. Hu-CAS consists of four modules: 1) collision risk assessment module to estimate collision priority between the ship and objects, 2) decision-making module to decide collision risk levels, 3) parameter estimation module needed in the ship control to avoid collisions and 4) control system to control the rudder angle and speed. Hu-CAS, proposed in this paper, can provide a novel system substitution current Autopilot and/or a CAS be teen manned vessel and Autonomous ship in a future.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.18 no.6
• /
• pp.1269-1276
• /
• 2023

Crop estimation is essential for the multinational meal and powerful demand due to its numerous aspects like soil, rain, climate, atmosphere, and their relations. The consequence of climate shift impacts the farming yield products. We operate the dataset with temperature, rainfall, humidity, etc. The current research focuses on feature selection with multifarious classifiers to assist farmers and agriculturalists. The crop yield estimation utilizing the feature selection approach is 96% accuracy. Feature selection affects a machine learning model's performance. Additionally, the performance of the current graph classifier accepts 81.5%. Eventually, the random forest regressor without feature selections owns 78% accuracy and the decision tree regressor without feature selections retains 67% accuracy. Our research merit is to reveal the experimental results of with and without feature selection significance for the proposed ten algorithms. These findings support learners and students in choosing the appropriate models for crop classification studies.