• Journal of the Korea Convergence Society
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• v.11 no.2
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• pp.75-83
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• 2020

This study aimed to understand the differences in general characteristics, principal diagnosis, injury-related characteristics, and types of transportation accidents between young-old and old-old patients who were hospitalized owing to injury based on data from the Korean National Hospital Discharge In-Depth Injury Surveys. We used a complex sample cross tabulation analysis (chi-square test) and complex sample generalized linear model (t-test). Therefore, the primary focus of healthcare professionals working with the old-old should prevent falls in the home and increase the available medical care, financial aid plans, and psychosocial support for aging. Additionally education on traffic accident prevention and road safety is particularly important for old-old patients.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.293-293
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• 2021

자연유량이란 인위적 행위에 의한 하천의 유량 변화가 없는 개발되지 않은 상태의 하천유량을 말하며, 실제 유량을 측정하거나 관측자료를 활용한 장기유출모형을 통해 산정할 수 있다. 미계측 유역에 대한 강우-유출 모형 구축시, 무엇보다 실제 미계측유역에 적용시 나타날 수 있는 문제점을 최소화할 수 있는 방향으로 모형 개발이 이루어지는 것이 필요하다. 강우-유출 모형 매개변수의 수가 많아질수록 과적합(over-fitting)의 발생 소지가 증가하게 되며, 지역화 모형 구축시 불확실성을 더욱 가중시키게 된다. 이러한 이유로, 모형의 검정보다는 검증에 초점이 맞춰져 있어야 하며, 더불어 사용되는 강우-유출 모형의 매개변수가 적어야 한다. 본 연구에서는 대표 강우-유출모형의 선정시 여러 평가 기준 중 예측의 정확성 측면에서 통계적 지표를 통해 모형의 수행능력에 중점을 두었으며, 적은 개수의 매개변수를 갖음에도 불구하고 상대적 우수한 모의결과를 제공하는 GR4J(Ge'nie Rural a 4 parame tres Journalier)모형을 최적 유출모형으로 선정하여 댐 상류유역에 대한 자연유량 재현성능을 평가하였다. 최종적으로 강우-유출모형의 최적매개변수와 유역특성인자 사이의 상호연관성을 고려해 매개변수를 지역화하기 위하여, 본 연구에서는 두 가지 이상의 변량에 대한 상관성을 효과적으로 재현하는데 효과적이며, 자유로운 주변확률분포 선택과 결합확률분포의 추정이 용이한 장점이 있는 Copula 함수를 활용하였다. 제시된 방법론에 대한 적합성을 평가하기 위해 교차검증 관점에서 지역화된 매개변수의 적합성을 검토하였으며, 본 연구에서 도출된 결과는 유역특성에 따른 미계측유역의 자연유량 산정시 지역 매개변수를 강우-유출모형에 활용함으로써 신뢰성 있는 자연유량 산정 결과를 제공할 수 있을 것으로 판단된다.

• Information Systems Review
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• v.11 no.2
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• pp.23-44
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• 2009

U-Services are inevitably essential for the realization of u-Cities. Most local governments in Korea have expressed much interest in introducing u-Cites and related u-Services. Since researchers anticipate that developing u-Cities will produce economic effects, the Korea government has support local governments to develop u-Cities and necessary u-Services. However, the technology issues have been dominiated in the field of U-City services and most of the U-City services do not reflects all the complicated and pluralistic sides of environment, which are caused by future uncertainties in developing u-Cites. For the purpose of addressing the above uncertainties, this paper attempts to develop the possible scenarios for U-City services through a scenario planning approach. A focus group interview and survey with professionals in the field of planning u-Cities was performed to identify these uncertainties. Then, in order to investigate the validity of the scenario planning methodology, the u-Service "u-Water purity monitoring" is adopted. After considering the relevant issues, we developed two possible scenarios: a mutual linkage service among u-Service related organization and a cooperating and coordinating service among local governments. On the basis of these scenarios, the strategies for potential U-City services are formulated. Various participants in developing U -City services are encouraged to use the scenarios as the foundation of predicting future features of u-Cities and developing the framework of the U-City service scenarios effectively.

• The Journal of the Korea Contents Association
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• v.8 no.6
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• pp.26-33
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• 2008

The customer relation marketing in which companies can utilize to control and to get the filtered information efficiently has appeared in ubiquitous commerce. It is applying data mining technique to build the management that can even predict and recommend products to customers. In this paper, we proposed the case of customer relation management application using the associative mining. The proposed method uses the associative mining composes frequent customers with occurrence of candidate customer-set creates the association rules. We analyzed the efficient the feature of purchase customers using the hypergraph partition according to the lift of creative association rules. Therefore, we discovered strategies of the cross-selling and the up-selling. To estimate the performance, the suggested method is compared with the existing methods in the questionnaire dataset. The results have shown that the proposed method significantly outperforms the accuracy than the previous methods.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.5
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• pp.37-43
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• 2009

Streaming video service over wireless and mobile communication networks has received significant interests from both academia and industry recently. Specifically, mobile WiMAX (IEEE 802.16e) is capable of providing high data rate and flexible Quality of Service (QoS) mechanisms, supporting mobile streaming very attractive. However, we need to note that streaming videos can be partially deteriorated in their macroblocks and/or slices owing to errors on OFDMA subcarriers, as we consider that compressed video sequence is generally sensitive to the error-prone channel status of the wireless and mobile network. In this paper, we introduce an OFDMA subcarrier-adaptive mobile streaming server based on cross-layer design. This streaming server system is substantially efficient to reduce the deterioration of streaming video transferred on the subcarriers of low power strength without any modifications of the existing schedulers, packet ordering/reassembly, and subcarrier allocation strategies in the base station.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.17-17
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• 2016

이중편파 레이더는 수평 수직반사도($Z_H{\cdot}Z_V$), 차등반사도($Z_{DR}$), 교차상관계수(${\rho}_{HV}$), 차등위상차(${\Phi}_{DP}$) 등 다양한 변수 산출을 통하여 대기 수상체 구분, 우적분포에 영향이 적은 강우량 추정, 밝은 띠(BB, Bright Band)의 탐지 등이 가능하게 됨으로써 수문기상 및 재해관리 분야에 활용성이 점점 더 커지고 있다. 본 연구는 RHI, PPI에서 생산된 레이더 변수를 이용하여 BB를 탐지하고 그 특성을 평가하였다. BB는 레이더를 이용하여 상층대기를 관측할 때 수직단면에서 강수입자가 눈에서 비로 변하는 구간에서 과대하게 높은 반사도가 나타나는 층을 말한다. BB에서는 QPE가 과대 추정되기 때문에, BB의 특성 파악은 레이더의 관측전략 수립과 QPE 보정에 필수적이다. 본 연구에서는 RHI에 의한 $Z_H$의 연직단면분석, RHI와 PPI의 고도각 경사거리(slant range) 빔의 ${\rho}_{HV}$, $Z_{DR}$, $Z_H$에 의한 분석을 통하여 BB의 상단부($BB_{TOP}$), 최정점($BB_{PEAK}$) 및 하단부($BB_{BOTTOM}$)의 고도를 상호 비교 평가하였다. 분석 자료는 KICT X-밴드 레이더에 의한 관측한 2015년 10월 21일의 층상운에 의한 강우를 이용하였다. RHI에 의한 $Z_H$의 연직단면 분석결과 $BB_{top}$, $BB_{bottom}$ 및 $BB_{peak}$는 KICT 레이더 고도(MSL : 40m)를 기준으로 각각 3.26Km, 2.3Km($BB_{width}$: 0.96km) 및 2.7Km로 나타났다. 이 같은 결과는 다른 2가지 분석방법에서도 유사하게 나타나고 있으며, 이는 BB분석을 위해 다양한 변수를 통한 신뢰성 있는 BB의 특성을 파악할 수 있는 기반을 제공한다.

• Journal of the Korea Convergence Society
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• v.13 no.4
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• pp.79-88
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• 2022

The objective of this study was to assess the association of changes in behaviors and depressed mood during the COVID-19 pandemic in Korea. A cross-sectional internet-based survey was conducted, using proportional samples of Korean adults and a logistic regression model was used to assess the association. As a result, negative changes of daily sitting or lying down time, daily walking time, smoking, and alcohol consumption were associated with being more depressed during the COVID-19 pandemic [odds ratios (ORs): 2.23 (95% CI=1.77-2.81), 2.04 (95% CI=1.63-2.56), 2.84 (95% CI=1.51-5.36), and 1.82 (95% CI=1.26-2.63), respectively]. This indicates that strategies to promote positive health behaviors change (increased activities and decreased consumption of smoking and alcohol) could help address psychological distress during the COVID-19 pandemic.

• Journal of agricultural medicine and community health
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• v.42 no.3
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• pp.119-131
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• 2017

Objectives: The purpose of this study was to compare the diabetic management indicators between agriculture, forestry, and fishery workers (AFF) and other occupational adults (non-AFF) in community-dwelling diabetes. Methods: The study population consisted of 22,127 diabetic population ${\geq}19years$ who participated in the 2015 Community Health Survey. Chi-square test and logistic regression analysis was used to compare the diabetic management indicators between AFF and non-AFF. Socioeconomic characteristics such as age, gender, education level, monthly household income, National Basic Livelihood Security status, and marital status was sequentially adjusted. Results: Among total diabetic population, 3,712 people (16.8%) was AFF and 18,415 people (83.2%) was non-AFF. The fully-adjusted odds ratio [OR] (95% confidence interval [CI]) of current non-medical treatment (0.72, 0.66-0.79), measurement of hemoglobin A1c (0.61, 0.55-0.67), screening for diabetic retinopathy (0.76, 0.70-0.83), screening for diabetic nephropathy (0.75, 0.70-0.81), non-alcoholic or moderate drinking (0.70, 0.64-0.78), nutrition label reading (0.83, 0.71-0.98), low salt preference (0.85, 0.78-0.93), dental examination (0.60, 0.54-0.66), scaling experience (0.84, 0.77-0.93), regular toothbrushing (0.66, 0.58-0.76), and diabetes management education (0.84, 0.77-0.92) was significantly lower in AFF compared to non-AFF. In contrast, the fully-adjusted OR (95% CI) of AFF's low stress level (1.39, 1.26-1.52) and adequate sleep duration (1.22, 1.13-1.32) was significantly higher than non-AFF, which are better indicators of diabetic management in AFF. Conclusions: Overall, the level of diabetes management of AFF was not as good as that of non-AFF. In order to improve the level of diabetes management of AFF, a delicate diabetes intervention strategy considering the occupational characteristics of AFF will be needed.

• The Korean Journal of Financial Management
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• v.21 no.1
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• pp.205-229
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• 2004

The deviation from put-call parity condition may affect market prices since it provides an opportunity of arbitrage to many participants. This study uses the KOSPI200 index data and examines the interdependence among spot, futures, and options contracts by examining whether the deviations from the parity have significant roles in price formation. Whenever the parity condition is violated, the deviation tends to affect the prices significantly in most markets. The results show that positive values of deviation are associated with the fall of the prices in the spot and put option contracts and the rise of the call option premiums, thus decreasing the deviations. Also, the decreasing impact of deviations lasts for at Beast an hour in most markets. Futures prices, however, do not show clear relations with the deviations, which suggests the possibility that futures markets lead other markets.

• Journal of Environmental Impact Assessment
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• v.27 no.2
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• pp.203-214
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• 2018

The purpose of this study is to estimate the concentrated distribution area of nutria (Myocastor coypus) and potential suitable habitat and to provide useful data for the effective management direction setting. Based on the nationwide distribution data of nutria, the cross-validation value was applied to analyze the distribution density. As a result, the concentrated distribution areas thatrequired preferential elimination is found in 14 administrative areas including Busan Metropolitan City, Daegu Metropolitan City, 11 cities and counties in Gyeongsangnam-do and 1 county in Gyeongsangbuk-do. In the potential suitable habitat estimation using a MaxEnt (Maximum Entropy) model, the possibility of emergency was found in the Nakdong River middle and lower stream area and the Seomjin riverlower stream area and Gahwacheon River area. As for the contribution by variables of a model, it showed DEM, precipitation of driest month, min temperature of coldest month and distance from river had contribution from the highest order. In terms of the relation with the probability of appearance, the probability of emergence was higher than the threshold value in areas with less than 34m of altitude, with $-5.7^{\circ}C{\sim}-0.6^{\circ}C$ of min temperature of the coldest month, with 15-30mm of precipitation of the driest month and with less than 1,373m away from the river. Variables that Altitude, existence of water and wintertemperature affected settlement and expansion of nutria, considering the research results and the physiological and ecological characteristics of nutria. Therefore, it is necessary to reflect them as important variables in the future habitable area detection and expansion estimation modeling. It must be essential to distinguish the concentrated distribution area and the management area of invasive alien species such as nutria and to establish and apply a suitable management strategy to the management site for the permanent control. The results in this study can be used as useful data for a strategic management such as rapid management on the preferential management area and preemptive and preventive management on the possible spreading area.