• Journal of Korea Water Resources Association
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• v.48 no.2
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• pp.91-103
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• 2015

This paper presents the systematic approach to positively skewed shape of instantaneous unit hydrograph (IUH), that is one of the universal features of hydrologic response function. To this end an analytical expression of statistical moments for IUH is derived within the framework of geomorphologic instantaneous unit hydrograph (GIUH) theory and quantified according to the concept of hydrodynamic, geomorphologic and kinematic heterogeneity. There is a big scale difference between hillslope and channel flow path system. Although the former has the much smaller level of scale its variation coefficient tends to be higher and coefficient of skewness has the different trend than the latter. The shape of IUH is likely to be much more affected by kinematic heterogeneity rather than hydrodynamic heterogeneity and its combined effect with geomorphologic heterogeneity is the major cause of skewing hydrologic response function. Statistical features of hillslope and channel flow path can be transferred into hydrologic response function in the form of dimensionless statistics and their relative importance forms the general shape of hydrologic response function.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.1
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• pp.62-71
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• 2016

Food insecurity is associated with poor health outcomes. In particular, previous studies marked the adverse outcomes on mental health. This study examined the association of food insecurity and mental health in Korean adults using the data from the 2013 Korean National Health and Nutrition Examination Survey (KNHANES). The study population was 5,685 adults in Korea. Food insecurity was examined using 18-items. A diagnosis of depression was considered to be depression. Depressive symptoms were defined as more than 2 weeks of depression feelings. Multivariate logistic regression models examined the associations between food insecurity and depression and depressive symptom. The overall prevalence of depression was 3.8% in the participants. Food insecurity was associated significantly with depression and depressive symptom in the unadjusted and age and sex adjusted model. Food insecurity was associated with depression, depressive symptoms in the multivariate logistic regression model (OR:3.49, OR:3.70). Marginal food insecurity was not associated with depression in the multivariate logistic regression model. The results showed that food insecurity is associated with depression and depressive symptoms in adults. Multi-disciplinary interventions are needed including nutrition, health, health policy, and a healthy environment for the food insecurity group to achieve a better health outcome, especially mental health.

• Journal of Science and Technology Studies
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• v.6 no.2 s.12
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• pp.103-129
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• 2006

In spite of decreased attention to digital divide, it has been pointed out as one of the main obstacles to realization of information society. At the outset, two conflicting explanations, optimism and pessimism, have directed their attention to objective basis of digital divide in common. They, however, have been neglected the fact that accessibilities can be varied not only by objective conditions but by subjective conditions such as individual recognition of necessity and willingness. Subsequent choices can be a crucial factor to determine whether to or not to access. In USA, over 50% of potential users determined not to access to the internet by their own will and choices. By the user survey on internet, 'do not feel the necessity' ranked the first reason not to use the internet in South Korea. The respondents who chose 'no time to use' tend to decrease but kept holding their shares, too. The relative importance of 'not to access' by individual choice have been increased. Whether the non-users of ICTs by choice is in or beyond the scope of digital divide, it evidently shows the necessity and importance of directing our attention to it on the way to information society.

• Journal of KIISE
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• v.42 no.2
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• pp.183-189
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• 2015

Recently, computer systems have encountered difficulties in making further progress due to the technical limitations of DRAM based main memory technologies. This has motivated the development of next generation memory technologies that have high density and non-volatility. However, these new memory technologies also have their own intrinsic limitations, making it difficult for them to currently be used as main memory. In order to overcome these problems, we propose a hybrid main memory system, namely HyMN, which utilizes the merits of next generation memory technologies by combining two types of memory: Write-Affable RAM(WAM) and Read-Affable RAM(ReAM). In so doing, we analyze the appropriate WAM size for HyMN, at which we can avoid the performance degradation. Further, we show that the execution time performance of HyMN, which provides an additional benefit of durability against unexpected blackouts, is almost comparable to legacy DRAM systems under normal operations.

• Journal of Korea Water Resources Association
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• v.52 no.11
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• pp.931-940
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• 2019

In hydrologic models, parameters are mainly used to reflect hydrologic elements or to supplement the simplified models. In this process, the proper selection of the parameters in the model can reduce the uncertainty. Accordingly, this study attempted to quantify the uncertainty of SWAT parameters using the General Likelihood Uncertainty Estimation (GLUE). Uncertainty analysis on SWAT parameters was conducted by using the formal and informal likelihood measures. The Lognormal function and Nash-Sutcliffe Efficiency (NSE) were used for formal and informal likelihood, respectively. Subjective factors are included in the selection of the likelihood function and the threshold, but the behavioral models were created by selecting top 30% lognormal for formal likelihood and NSE above 0.5 for informal likelihood. Despite the subjectivity in the selection of the likelihood and the threshold, there was a small difference between the formal and informal likelihoods. In addition, among the SWAT parameters, ALPHA_BF which reflects baseflow characteristics is the most sensitive. Based on this study, if the range of SWAT model parameters satisfying a certain threshold for each watershed is classified, it is expected that users will have more practical or academic access to the SWAT model.

• Annual Conference of KIPS
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• 2009.11a
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• pp.595-596
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• 2009

정보화의 발전에 비례하여 정보보호의 중요성도 높아지고 있다. 최근까지 정보보호에 대한 관심과 주요 연구의 흐름은 기술적인 보호조치(예: 암호화, 접근제어, 방화벽 등)와 관리적 관점의 행동연구였다. 최근에 들어서야 국내외적으로 정보보호 투자효과에 대한 연구가 활성화되기 시작했다. 정보보호 투자효과에 대한 계량적 산정이 필요한 이유는 정보보호의 중요성을 정확하게 인식할 수 있어 적정규모의 예산을 책정하고 효율적으로 예산을 투입할 수 있는 기초를 마련할 수 있기 때문이다. 정보보호 투자효과를 측정하기 위한 선행연구로 보안사고의 피해규모를 산정하는 연구가 필수적이다. 보안사고의 피해규모는 가시적 손실(피해복구, 생산성 저하, 손해배상 등)과, 비가시적 손실(고객 충성도 저하, 회사의 브랜드 이미지 하락 등) 규모의 합으로 구성된다. 그 동안 가시적 손실규모 측정에 관한 연구는 상대적으로 많았으나, 비가시적 손실규모 측정에 관한 연구는 상대적으로 미흡하였던 것이 사실이다. 이는 현실적으로 비가시적 손실규모를 측정할 수 있는 접근방법을 고안해내는 것이 어려웠기 때문이다. 이로 인해 막연히 비가시적 손실규모가 가시적 손실규모에 비해 대단히 클 것이라고 짐작해 올 수 밖에 없었다. 본 논문에서는 보안사고의 비가시적 손실규모를 측정하기 위해 대규모 개인정보 보안 사고가 발생한 기업의 매출액 증가율을 경쟁기업과 분석하는 연구방법을 제안한다. 매출액은 영업이익 및 순이익과는 달리 회사 내부적인 회계방침에 의해 규모의 조절이 불가능한 재무요소이면서 회사가 고객 충성도 저하와 회사의 브랜드 이미지 하락으로 인해 받게 되는 영향을 가장 정확하게 반영하는 재무요소이기도 하다. 연구방법에 따라 2008년 대규모 개인정보 보안사고가 발생한 국내기업을 선정하고 그 경쟁사와 매출액 변화추이를 비교 분석하였다. 분석결과 보안사고가 발생한 기업의 평균 매출액 증가율이 경쟁사 평균 매출액 증가율 보다 0.0225% 높다는 사실을 발견했다. 이 결과는 국내의 보안 사고가 기업 가치에 미치는 비가시적 영향이 거의 없거나 또는 발생하더라도 그 영향력이 미미하여 가격정책 및 광고 홍보를 통해 충분히 극복할 수 있다는 점을 대변한다. 본 논문의 결과는 역설적으로 국내 보안사고의 피해규모를 측정하는데 있어 가시적 손실규모의 정확한 측정이 무엇보다 중요함을 의미한다.

• Journal of the Korean Arthroscopy Society
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• v.8 no.2
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• pp.75-81
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• 2004

Purpose: Recent development and advances in arthroscopic surgical techniques for Anterior Cruciate Ligament(ACL) reconstruction have led to the ideal location for the etric point from 10 o'clock (in right knee) and 13:30 (in left knee) to 10:30 (in right knee) and 14 o'clock (in left knee) in the frontal plane. This study was performed to compare operative methods and the radiologic results of femoral tunnels made through the tibial tunnel(trans-tibial approach) and the anteromedial portal. Material and Methods: From January 2003 to May 2004, one-hundred reconstructions of anterior cruciate ligament were performed. Group I (femoral tunnel through tibial tunnel) was composed of 50 cases and group ll (femoral tunnel through anteromedial portal) was consisted of 50 cases. The study was performed to compare the radiographic results of femoral tunnels made through the tibial tunnel and the anteromedial portal and operative methods. Results: In operative methods at Group II, femoral tunnel was made more easily at isometric point than Group I, a good visual field was achived because 100$^{\circ}$ flxion of knee, they can be reduced risk of posterior cortical breakage and tunnel-graft mismatching and decreased divergence of femoral interference screw in radiology (P<0.05). The angle between femoral tunnel and longitudinal axis of ACL wae increased at Group ll. Conclusion: Aanteromedial portal technique was more useful in ACL reconstruction for femoral tunnel toward 10 o'clock to10:30(in right) or 1:30 to 2 o'clock(in left).

• Journal of Environmental Impact Assessment
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• v.27 no.4
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• pp.367-377
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• 2018

A cultural ecosystem service(CES), which is non-material benefit that human gains from ecosystem, has been recently further recognized as gross national income increases. Previous researches proposed to quantify the value of CES, which still remains as a challenging issue today due to its social and cultural subjectivity. This study proposes new way of assessing CES which is called Cultural Service Opportunity Spectrum(CSOS). CSOS is accessibility based CES assessment methodology for regional scale and it is designed to be applicable for any regions in Korea for supporting decision making process. CSOS employed public spatial data which are road network and population density map. In addition, the results of 'Rapid Assessment of Natural Assets' implemented by National Institute of Ecology, Korea were used as a complementary data. CSOS was applied to Namyangju-si and the methodology resulted in revealing specific areas with great accessibility to 'Natural Assets' in the region. Based on the results, the advantages and limitations of the methodology were discussed with regard to weighting three main factors and in contrast to Scenic Quality model and Recreation model of InVEST which have been commonly used for assessing CES today due to its convenience today.

• Journal of the Korea Society of Computer and Information
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• v.20 no.6
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• pp.59-76
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• 2015

Recent wide spread of embedded devices and technology growth of broadband communication has led to rapid increase in the volume of created and managed data. As a result, data centers have to increase the storage capacity cost-effectively to store the created data. Data deduplication is one way to save the storage space by removing redundant data. This work propose IO extent based deduplication schemes called CORE-Dedup that exploits content-preserving access locality. We acquire IO traces from block device layer in virtual machine host, and compare the deduplication performance of chunking method between the fixed size and IO extent based. At multiple workload of 10 user's compile in virtual machine environment, the result shows that 4 KB fixed size chunking and IO extent based chunking use chunk index 14500 and 1700, respectively. The deduplication rate account for 60.4% and 57.6% on fixed size and IO extent chunking, respectively.

• Journal of Digital Convergence
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• v.11 no.10
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• pp.255-262
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• 2013

Data envelopment analysis(DEA) is a linear programming procedure designed to evaluate the relative efficiency of a set of peer entities called decision making units which use the same inputs to produce the same outputs. It has been widely employed in a variety of disciplines as an efficiency or performance measurement tool for comparing a set of entities such as firms, banks, hospitals, nations and organizations. The method, however, cant's make the priority of their performance when many units have efficiency score of unity or 100 percent. In this paper, we propose a new approach which combine qualitative method(graphical approach using network analysis) and quantitative method(super-efficient analysis using DEA), and present the results of an empirical analysis using the data of the Korean professional baseball players. As a result, there were 12 DMU that priority is hardly realized through DEA. However, this problem could be solved with super-efficiency analyzing. Also, more in-depth interpretation was able through integrating results of dendrogram and super-efficiency analyzing and prospecting it in qualitative, quantitative ways.