• The Korean Journal of Applied Statistics
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• v.17 no.1
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• pp.49-60
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• 2004

In this paper, when the observations are distributed as inverse gaussian, we developed the noninformative priors for ratio of the parameters of inverse gaussian distribution. We developed the first order matching prior and proved that the second order matching prior does not exist. It turns out that one-at-a-time reference prior satisfies a first order matching criterion. Some simulation study is performed.

• The Korean Journal of Applied Statistics
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• v.37 no.2
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• pp.209-224
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• 2024

Speaker verification is becoming popular as a method of non-face-to-face identity authentication. It involves determining whether two voice data belong to the same speaker. In cases where the criminal's voice remains at the crime scene, it is vital to establish a speaker verification system that can accurately compare the two voice evidence. In this study, to achieve this, a new speaker verification system was built using a deep learning model for Korean language. High-dimensional voice data with a high variability like background noise made it necessary to use deep learning-based methods for speaker matching. To construct the matching algorithm, the ECAPA-TDNN model, known as the most famous deep learning system for speaker verification, was selected. A large dataset of the voice data, Voxceleb, collected from people of various nationalities without Korean. To study the appropriate form of datasets necessary for learning the Korean language, experiments were carried out to find out how Korean voice data affects the matching performance. The results showed that when comparing models learned only with Voxceleb and models learned with datasets combining Voxceleb and Korean datasets to maximize language and speaker diversity, the performance of learning data, including Korean, is improved for all test sets.

• Journal of Applied Reliability
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• v.17 no.1
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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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• v.39 no.1
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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.

• Journal of Broadcast Engineering
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• v.7 no.4
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• pp.310-316
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• 2002

In this paper, we propose an adaptive search range decision algorithm for fast motion estimation of video coding. Block matching algorithm for motion vector estimation that improves coding efficiency by reduction of temporal redundancy has trade-off problem between the motion vector accuracy and the complexity. The proposed algorithm playing as a pre-processing of fast motion estimation adaptively determines the motion search range by the local statistics of neighboring motion vectors. resulting in dramatic reduction of the computational cost without the loss of coding efficiency. Experimental results show the capability of the proposed algorithm.

• The Korean Journal of Applied Statistics
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• v.25 no.1
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• pp.163-181
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• 2012

This paper studies the effect of job training for non-regular employees in the Korea labor market. Using an economically active population data set of statistics Korea, we apply a non-parametric matching and sensitivity analysis method to measure the effect of the training for non-regular employees and to look for the impact of an unobservable variable or confounding factor in regards to the selection effect and outcome effect. In the our empirical results, we conclude that the effect of the training for non-regular employees has a better employment effect for getting a regular job rather than a wage effect; in addition, the impact of unobservable variables or confounding factors do not exercise a statistically strong influence on the baseline ATT.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.4
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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.

• Journal of Korean Society for Quality Management
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• v.44 no.2
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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.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.34 no.2
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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.

• Korean Journal of Clinical Pharmacy
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• v.33 no.3
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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.