• Proceedings of the Korea Information Processing Society Conference
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• 2020.11a
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• pp.380-382
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• 2020

네트워크에 존재하는 저장 공간을 필요에 따라 유연하게 대여하여 사용할 수 있는 클라우드 스토리지 서비스는 데이터의 일관성 유지, 저렴한 유지관리 비용 등 여러 장점에 힘입어 널리 활용되고 있다. 하지만 클라우드 시스템은 데이터 소유자에 의한 관리가 이루어지지 않으므로 민감한 데이터의 노출에 의한 피해 또한 다수 발생하고 있는데, 이를 해결하기 위하여 암호화 등을 통한 프라이버시 보존을 위한 연구가 꾸준히 진행되고 있다. 본 연구에서는 프라이버시가 보존된 상태에서 클라우드에 저장된 데이터를 검색함에 있어, 대수적 난제에 근거를 둔 접근 제어 기능을 내포한 소프트웨어 기반의 검색 가능한 암호화 (searchable encryption) 기법과 최근 많은 관심을 받고 있는 하드웨어 기반 클라우드 데이터 검색의 효율성 및 기능에 대한 비교 분석을 수행한다. 이를 통하여 하드웨어 기반 기법의 활용을 통한 성능 향상 가능성을 확인하고 잠재적 보안 위협을 검토한다.

• Journal of the Korea Society of Computer and Information
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• v.27 no.9
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• pp.41-47
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• 2022

In this paper, we propose a new and simple self-supervised learning method that predicts the middle image of a face image sequence for automatic expression recognition. Automatic facial expression recognition can achieve high performance through deep learning methods, however, generally requires a expensive large data set. The size of the data set and the performance of the algorithm are tend to be proportional. The proposed method learns latent deep representation of a face through self-supervised learning using an existing dataset without constructing an additional dataset. Then it transfers the learned parameter to new facial expression reorganization model for improving the performance of automatic expression recognition. The proposed method showed high performance improvement for two datasets, CK+ and AFEW 8.0, and showed that the proposed method can achieve a great effect.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.694-697
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• 2004

최근 빠르게 성숙되고 있는 시장과 경쟁적 환경으로 인해 고객 유지에 대한 중요성이 증대되고 있다. 이는 기존 고객을 유지하는 것이 비용 면에서 저렴할 뿐 아니라, 고객 충성도나 구전효과가 같은 기타 부수적인 이득을 획득할 수 있다는 측면에서 유리하기 때문이다. 본 논문은 고객의 이탈 가능성을 미리 예측하고 이를 사전에 방지할 수 있는 고객 유지 절차를 제시하고 있다. 이탈고객의 탐지 및 방지를 위해서는 기존의 인구통계학적 자료 외에도 웹로그, 구매 Database 등의 대용량의 고객 행위 데이터에 대한 분석이 요구되기 때문에 데이터 마이닝 기법의 활용이 필수적이다. 그러나 대부분의 데이터 마이닝 연구는 예측 및 분류의 정확성이 높은 모델을 개발하는데 초점이 맞추어져 있으며, 고객의 행위를 이해하고 바람직한 방향으로 유도하고자 하는 연구는 지극히 부족한 상황이다. 그러므로 본 논문은 다양한 데이터마이닝 기법을 통합하여 잠재 이탈고객을 탐지하고, 기존 연구에서 간과하고 있던 비용적 측면을 고려한 이탈 방지 절차를 제시하고자 한다.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.458-461
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• 2006

With the opening in construction market, more diversified and internationalized construction culture is imported, but the level of our construction culture and policy is still not met the international standards. For example, there is a difference in the liquidated damages at delay due to the reason of builder imputation during the public construction project comparing the international standards like damages. It may lead to the potential claim. In this study, via comparing and analysis on the relevant international standards and extension expense for terms of work, actual compensation is selected, and improvement of liquidated damages like damages is presented.

• Journal of Life Science
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• v.33 no.6
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• pp.490-497
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• 2023

Pregnant women may need to take medications to treat preexisting diseases or diseases that develop during pregnancy. However, some drugs may be fetotoxic and lead to, for example, teratogenicity and growth retardation. Predicting the fetotoxicity of drugs is thus important for the health of the mother and fetus. The fetotoxicity of many drugs has not been established because various challenges hinder the ability of researchers to determine their fetotoxicity. The need exists for in silico-based fetotoxicity assessment models, as they can modernize the testing paradigm, improve predictability, and reduce the use of animals and the costs of fetotoxicity testing. In this study, we collected data on the fetotoxicity of drugs and constructed fetotoxicity prediction models based on various machine learning algorithms. We optimized the models for more precise predictions by tuning the hyperparameters. We then performed quantitative performance evaluations. The results indicated that the constructed machine learning-based models had high performance (AUROC >0.85, AUPR >0.9) in fetotoxicity prediction. We also analyzed the feature importance of our model's predictions, which could be leveraged to identify the specific features of drugs that are strongly associated with fetotoxicity. The proposed model can be used to prescreen drugs and drug candidates at a lower cost and in less time. It provides a predictive score for fetotoxicity risk, which may be beneficial in the design of studies on fetotoxicity in human pregnancy.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1D
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• pp.195-202
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• 2006

The infiltration route analysis is a military application using geospatial information technology. The result of the analysis would present vulnerable routes for potential enemy infiltration. In order to find the susceptible routes, optimal path search algorithms (Dijkstra's and $A^*$) were used to minimize the cost function, summation of detection probability. The cost function was produced by capability of TOD (Thermal Observation Device), results of viewshed analysis using DEM (Digital Elevation Model) and two related geospatial information coverages (obstacle and vegetation) extracted from VITD (Vector product Interim Terrain Data). With respect to 50m by 50m cells, the individual cost was computed and recorded, and then the optimal infiltration routes was found while minimizing summation of the costs on the routes. The proposed algorithm was experimented in Daejeon region in South Korea. The test results show that Dijkstra's and $A^*$ algorithms do not present significant differences, but A* algorithm shows a better efficiency. This application can be used for both infiltration and surveillance. Using simulation of moving TOD, the most vulnerable routes can be detected for infiltration purpose. On the other hands, it can be inversely used for selection of the best locations of TOD. This is an example of powerful geospatial solution for military application.

• 한국벤처창업학회:학술대회논문집
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• 2017.08a
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• pp.15-35
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• 2017

The purpose of this research is to investigate the factors which effect the intention to reemploy after the retirement and the mediation effect of the social capitalism for retired and prospective retired baby boomers. Starting from 2010, baby boomers have been retiring at a large scale. However retirement at a large scale without securing provision for fiancial wise in later life can lead to many issues regarding social and fiancial wise such as instability of labour market and increase of spending in society welfare cost and such on. Change of individual's self prospective and institutional support to help prepare find new career for next 3decade after the retirement needs to be concretized. Also, while in the work force, potential retiring baby boomer workers should be systematically supported with education, training and reemployment program based on individual's career orientation and allowing them to stay for a longer period in the labour market can be the implication to the solution for the economic stability and increasing social cost such as public pensions.

• The Journal of the Korea Contents Association
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• v.22 no.1
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• pp.99-115
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• 2022

In this study, domestic academic journal papers on tax compliance, tax consciousness, and faithful tax payment (hereinafter referred to as "tax compliance") were comprehensively analyzed from an interdisciplinary perspective as a representative research topic in the field of tax science. To achieve the research purpose, topic modeling technique was applied as part of text mining. In the flow of data collection-keyword preprocessing-topic model analysis, potential research topics were presented from tax compliance related keywords registered by the researcher in a total of 347 papers. The results of this study can be summarized as follows. First, in the keyword analysis, keywords such as tax investigation, tax avoidance, and honest tax reporting system were included in the top 5 keywords based on simple term-frequency, and in the TF-IDF value considering the relative importance of keywords, they were also included in the top 5 keywords. On the other hand, the keyword, tax evasion, was included in the top keyword based on the TF-IDF value, whereas it was not highlighted in the simple term-frequency. Second, eight potential research topics were derived through topic modeling. The topics covered are (1) tax fairness and suppression of tax offenses, (2) the ideology of the tax law and the validity of tax policies, (3) the principle of substance over form and guarantee of tax receivables (4) tax compliance costs and tax administration services, (5) the tax returns self- assessment system and tax experts, (6) tax climate and strategic tax behavior, (7) multifaceted tax behavior and differential compliance intentions, (8) tax information system and tax resource management. The research comprehensively looked at the various perspectives on the tax compliance from an interdisciplinary perspective, thereby comprehensively grasping past research trends on tax compliance and suggesting the direction of future research.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.55-55
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• 2017

가뭄은 국민생활 및 경제 등에 막대한 손실을 초래하며, 지역사회 공동체나 사회기능에 심각한 영향을 끼칠 수 있는 재해이다. 가뭄피해 최소화를 위해서는 단기대응, 복구지원 등의 사후대책에서 사전대비 및 예방으로의 정책 전환이 필요하며, 이러한 정책 수립을 뒷받침하기 위해서는 가뭄에 따른 정량적인 피해영향 평가가 우선적으로 필요하다. 하지만 가뭄 피해의 범위 및 형태는 워낙 광범위하기 때문에, 피해추정을 위한 잣대라 할 수 있는 영향평가 기법조차 제대로 정립되지 못하고 있는 실정이다. 국내에서는 분야별(기상, 농업, 수문)로 지수화 된 지표를 이용한 가뭄 평가가 주로 수행되고 있으며, 경제적 영향평가는 방법론에 대한 시범 연구 수준이다. 가뭄기록조사 등 과거 가뭄피해 자료에서도 피해액의 금액환산이 되지 않은 사례가 대부분이며 급수차지원, 관정개발 등 사후복구비 위주의 일부 자료만이 피해금액으로 제시되어 있을 뿐이다. 댐, 저수지 등에 의한 용수공급 안정성으로 인해, 기상학적인 가뭄이 즉시 물부족으로 인한 피해로 이어지지는 않지만, 물부족이 발생하거나 부족량이 예측되는 상황에서 피해규모를 시스템적으로 추정 및 비교할 수 있는 기법 개발의 필요성에 의해 잠재피해액 개념의 공급지장비용 추정기법을 개발하였다. 공급지장비용 또는 편익 도출을 위한 이론적 배경으로, 경제적 가치 또는 파급효과를 분석하기 위한 방법은 경제학적 접근법과 비경제학적 접근법으로 구분된다. 경제학적 접근법에서 사용하는 진술선호 기법의 경우 전국을 대상으로 설문 등의 과정을 거쳐 지불의사액을 도출하는 과정이 필요하기 때문에 많은 조사비용이 소요된다. 비경제학적 또는 공학적 접근법으로 분류되는 대체비용법은 이론적 배경이 약하고 대체항목의 선택에 주의가 필요하다는 단점이 있으나, 물가자료, 산업통계, 수자원통계 등 기초자료의 주기적 업데이트가 유리하며, 정신적 피해를 제외할 경우 피해비용 추정결과의 편차가 진술선호기법 보다는 작은 장점이 있다. 본 연구에서는 피해비용의 과대추정에 유의하여 대체비용법에 기반한 일본 후생노동성의 감 단수피해추정기법을 우리나라 자료에 맞게 수정하여 공급지장비용을 추정하였으며, 경제학적 접근법에 의한 용수의 한계가치비용 등과 비교를 통해 적용성을 검토하였다.

• The Journal of the Korea Contents Association
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• v.15 no.6
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• pp.455-462
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• 2015

This paper examines the effect of corporate social responsosibility(CSR) on the firm value. Based on the argument that CSR would play the role of mitigating conflicts between firms and society, I hypothesized that CSR would enhance the firm value. This study used regression analysis with a data set of 733 from 2009 to 2012 using KEJI(Korean Economic Justice Institute) Index. An Index published by KEJI was used as the measure of CSR performance. The results of this study are summarized as follows: First, there is a significant positive relation between CSR and firm value. Second, in the seven-rating items consist of the KEJI Index, most items have the positive relationship with the firm value. These results suggest that firm with higher CSR activities exhibit better financial performance as measured by Tobin's Q.