• 응용통계연구
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• 제17권1호
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• pp.49-60
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• 2004

이 논문의 목적은 역 가우스 분포의 모수비가 관심의 대상일 때, 그 모수비에 대한 무정보적 사전분포를 구하는데 있다. 특별히, 모수비에 대한 확률대응사전분포와 기준 사전분포를 제안하였다. 먼저, 관심의 대상이 되는 모수에 대해 모수 직교화 변환을 구하고, 모수 직교화 변환을 이용하여 확률대응사전분포와 기준사전분포를 구하였다. 특히 확률대응사전분포의 일치차수는 1차임을 보였으며 2차 확률대응사전분포는 존재하지 않음을 보였다. 또한 제안된 사전분포에 의해 유도된 사후분포는 적절 분포임을 증명하였다. 모의 실험을 통하여 확률대응사전분포와 기준사전분포를 비교했으며, 실제자료를 이용하여 분석하는 예를 보였다.

• 응용통계연구
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• 제37권2호
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• pp.209-224
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• 2024

화자검증(speaker verification)이란 두개의 음성 데이터로부터 같은 화자의 목소리 인지 아닌지를 판단하는것을 말한다. 범죄현장에서 범인의 목소리만이 증거로 남는경우, 두개의 목소리를 객관적이고 정확하게 비교할 수 있는 화자 검증 시스템 또는 화자 매칭 시스템의 구축이 시급하다. 본 연구에서는 한국어에 대한 화자검증 딥러닝 모형을 새롭게 구축하고, 학습에 필요한 적절한 형태의 학습데이터셋에 대해 연구한다. 음성데이터는 고차원이면서 백그라운드 노이즈를 포함하는 등의 변동성이 큰 특징이 있다. 따라서 화자 검증 시스템을 구축하기위해 딥러닝 기반의 방법 선택하는경우가 많다. 본 연구에서는 ECAPA-TDNN 모형을 선택하여 화자 매칭 알고리즘을 구축하였다. 구축한 모형을 학습시키는데 사용한 Voxceleb은 대용량의 목소리 데이터로 다양한 국적을 가진 사람들로부터 음성데이터를 포함하지만 한국어에 대한 정보는 포함하지 않는 다. 본 연구에서는 한국어 음성데이터를 학습에 포함시켰을때와 포함시키지 않았을때 학습 데이터 내 해당언어의 존재 유무가 모델의 성능에 미치는 영향에 대해 파악하였다. Voxceleb으로만 학습한 모델과 언어와 화자의 다양성을 최대로 하기 위해 Voxceleb과 한국어 데이터셋을 결합한 데이터셋으로 학습한 모델을 비교하였을 때, 모든 테스트 셋에 대해 한국어를 포함한 학습데이터의 성능이 개선됨을 보인다.

• 한국신뢰성학회지:신뢰성응용연구
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• 제17권1호
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• pp.38-49
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• 2017

Purpose: The purpose of this study is to introduce the assessment model for industrial accidents prevention policy. Methods: 10 years of industrial accidents data are explored through EDA approach. Case control study is tried in order to assess the effectiveness of the measures taken by Korea Safety and Health Agency, Civilian, and 'Ministry of Employment and Labor'. Propensity score matching is used to match the characteristics of the two groups compared, and then case control study is again conducted. Next, logistic and Poisson regressions are used to assess the risk factors. Results: According to case control study involvement of 'Korea Safety and Health Agency' and 'Ministry of Employment and Labor' were not effective, but Civilian was. Propensity score matching leads to the same conclusion. Poisson regression reveals the impact of the risk factors on the industrial accidents. Industrial accidents occur more often as the number of employees grows. Mining, farming, fishing, 'transportation storage and telecommunication' and forestry have a higher level of industrial accidents but service industry has a lower level. It is odd that more involvement of Korea Safety and Health Agency, Civilian, and Ministry of Employment and Labor means more industrial accidents. Conclusion: 'Korea Safety and Health Agency', Civilian, and 'Ministry of Employment and Labor' seem to visit those industries with more industrial accidents.

• KDI Journal of Economic Policy
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• 제39권1호
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• pp.1-18
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• 2017

This paper empirically studies the effect of public procurement on small and medium-sized enterprises (SMEs) in the Republic of Korea using firm-level data. Public procurement, the purchase of goods and services from private firms by the public sector, is regarded as an important policy measure for providing support to firms, particularly SMEs. This study uses establishment-level panel data of the mining and manufacturing sectors from the Korean National Bureau of Statistics (Statistics Korea) and procurement history from the Korean Public Procurement Service to empirically estimate the effects of public procurement on firms' productivity (total factor productivity) and survivability. Using a propensity score matching estimation method, we find that participating firms showed higher productivity than non-participating ones in the control group only for the year of participation, that is, 2009. After two years, in 2011, they exhibited significantly lower productivity. In contrast, establishments that participated in public procurement for SMEs in 2009 were more likely to survive than those that did not do so in 2011. These results can be interpreted as the negative consequences of government intervention. The market's efficiency enhancement is hindered if underserving companies survive owing to government intervention but fail to improve efficiency.

• 방송공학회논문지
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• 제7권4호
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• pp.310-316
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• 2002

본 논문에서는 동영상 부호화 시 움직임 벡터의 고속 추정을 가능하게 하기 위한 적응 탐색 영역 결정 방식에 대해 제안한다. 시간적 과잉정보를 제거함으로써 압축 효율을 개선하고자 하는 움직임 벡터 추정을 위한 블록 매칭 방식 (BMA: Block Matching Algorithm)은 움직임 벡터의 정확성 및 계산량 측면에서 상호 교환적인 특성을 갖고 있다. 고속 움직임 추정을 위한 전처리 과정인 제안 방식은 인접 블록 움직임 벡터의 국부 통계 특성을 이용하여 움직임 탐색 영역을 적응적으로 결정한다. 실험 결과를 통해 제안된 방식이 압축 효율의 손상 없이 상당한 계산량이 줄었음을 확인할 수 있었다.

• 응용통계연구
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• 제25권1호
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• pp.163-181
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• 2012

비정규직 재직자 직업능력개발에 대한 훈련 효과 추정을 위해 이 연구에서는 통계청의 경활 자료와 비모수적 매칭 방법을 사용하였다. 추정결과 재직자 직업능력개발 훈련은 정규직 자에게는 정규직 유지가능성을 높이고 비정규직 자에게는 임금보다는 정규직 전환확률을 높이는 것으로 나타났다. 또한 미관찰 요인에 의한 추정결과의 강건성을 알아보는 민감도 분석에서는 미관찰 요인은 추정결과에 크게 영향을 미치지 않는 것으로 나타났다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권4호
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• pp.1066-1079
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• 2023

Multi-target tracking based on the detector is a very hot and important research topic in target tracking. It mainly includes two closely related processes, namely target detection and target tracking. Where target detection is responsible for detecting the exact position of the target, while target tracking monitors the temporal and spatial changes of the target. With the improvement of the detector, the tracking performance has reached a new level. The problem that always exists in the research of target tracking is the problem that occurs again after the target is occluded during tracking. Based on this question, this paper proposes a DeepSORT model based on SIFT features to improve ship tracking. Unlike previous feature extraction networks, SIFT algorithm does not require the characteristics of pre-training learning objectives and can be used in ship tracking quickly. At the same time, we improve and test the matching method of our model to find a balance between tracking accuracy and tracking speed. Experiments show that the model can get more ideal results.

• 품질경영학회지
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• 제44권2호
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• pp.341-356
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• 2016

Purpose: The purpose of this paper is to study whether the adoption of Six Sigma quality management by a firm positively affects its financial performance. The correlation between the duration of Six Sigma implementation period and the financial status of the firm is investigated as well. Methods: We conduct the analysis using data from Manufacturing Industry Productivity Panel Survey 2013 provided by Korea Productivity Center and Ministry of Trade, Industry and Energy. Propensity score matching is used to reduce sample selection bias of observational study. Furthermore, we use multiple linear regression in order to study the relationship between the implementation of Six Sigma quality management and financial performance. The return on assets and ratio of net income to net sales are considered as dependent variable and implementation of Six Sigma as independent variable. Results: The indication of this analysis is that implementation of Six Sigma quality management does not significantly enhance financial status. The firms that adopted Six Sigma quality management were categorized into three groups according to the implementation period. Comparison of each group with the firms that do not adopt Six Sigma quality management does not show statistically significant enhancement of financial status. Conclusion: In conclusion, both adoption and duration of six sigma quality management do not affect financial performance significantly.

• 한방안이비인후피부과학회지
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• 제34권2호
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• pp.53-69
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• 2021

Objectives : The purpose of this study is to analyze the effects of treatment between Western medicine and Korean medicine on Allergic rhinitis patients using national population-based claim data from the Health Insurance Review and Assessment Service. Methods : The subjects of the study were 30,024 patients in the Korean medicine group and 30,024 in the Western medicine group who were diagnosed with Allergic rhinitis from September 1, 2018 to December 31, 2018. Propensity score analysis was used for matching age, sex, etc. at a ratio of 1:1. Cox regression and subgroup analysis were used to estimate the adjusted hazard ratio of recurrence, Asthma, and Atopic dermatitis in Korean medicine group and Western medicine group. In addition, the total treatment period, total treatment cost, and average cost per day of visit were compared and analyzed. Results : Compared to Korean medicine, Western medicine had a significantly higher risk of recurrence at 1.701 times, Asthma occurrence risk at 1.609 times and Atopic dermatitis occurrence risk at 1.098 times. Compared to Western medicine, the total treatment period of Korean medicine was 14.27 days longer, the total treatment cost was 53,591 won more, and the average cost per day was 7,539 won more. Conclusions : This study is a retrospective cohort study using the propensity score matching in Korea to compare the outcomes of Allergic rhinitis between Western medicine and Korean medicine. Further research is needed by considering patients characteristics, and linking with additional data.

• 한국임상약학회지
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• 제33권3호
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• pp.178-185
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• 2023

Objective: Atopic dermatitis (AD) is a chronic, recurrent inflammatory skin disease. Both tralokinumab and dupilumab have been recommended in the European Guideline for the treatment of adult patients with severe AD. In Korea, dupilumab has been approved for patients with moderate to severe AD, and reimbursed for those with severe AD. Since there is no clinical trial directly comparing tralokinumab and dupilumab, we conducted indirect comparison to assess the clinical usefulness in patients with AD. Methods: We selected clinical trials for indirect comparison through a systematic literature review. Individual patient data were available for the tralokinumab clinical trial, and aggregated data were available for the dupilumab clinical trial. Therefore, we employed the Matching-Adjusted Indirect Comparison (MAIC) method. The treatment efficacy was assessed based on whether patients achieved a 75% reduction on the Eczema Area and Severity Index (EASI 75) after drug administration. Results: The difference in the proportion of patients achieving EASI 75 between tralokinumab and dupilumab was 4.7% (95% CI: -7.9 to 17.3). Considering the non-inferiority margin for the EASI 75 achievement rate is -10%, tralokinumab is deemed non-inferior to dupilumab as the lower bound of the CI for the difference in the EASI 75 achievement rate between tralokinumab and dupilumab was within -10%. Conclusion: We conducted a MAIC analysis comparing tralokinumab and dupilumab based on EASI 75 achievement. The findings of this study show that tralokinumab is non-inferior to dupilumab and can be implemented in Korean clinical settings with a therapeutic position comparable to dupilumab.