• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.10
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• pp.2451-2461
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• 2014

Mobile application is software executing on smart devices regardless of the time and place. Many individuals and companies have provided a lot of mobile applications services. However, there is not certain standard in terms of application's quality evaluation because study is deficient compared with increase amount of development of mobile application. Moreover, mobile application basically has many special characteristics. For these reasons mobile application is required special standard of quality different from general software. To satisfy these needs, I design and propose mobile application evaluation model. Evaluation model is mapped by characteristics of mobile application based on ISO/IEC 25000's quality characteristics and propose each quality characteristics and metrics. For verification, scenario-based studies were applied to quality model and carried out.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.335-335
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• 2012

기후변화에 의한 미래 수문량 전망에 대한 연구는 전지구 모델 결과를 바탕으로 이루어진다. 현재 전지구 모델의 모의 결과 생산된 강우 자료는 기상청에서 제공되며, 제공된 자료는 기상청 관측 지점에 국한되어 있다. 어떤 유역의 확률홍수량 전망은 유역내 강우 지점의 확률강우량을 강우-유출 모형인 HEC-1에 입력하여 추정할 수 있다. 한강 유역과 같은 대유역의 확률홍수량을 구하기 위해서는 유역내 기상청 관측 지점만으로는 지점수가 부족하기 때문에 국토해양부나 수자원공사 관할의 지점 자료를 활용한다. 하지만 이러한 대유역의 미래 확률홍수량을 전망하고자 하는 경우에 제공되는 전지구 모델 결과가 기상청 지점에 국한되어 있어 다른 지점의 확률강우량을 산정하는 데 어려움이 있다. 본 연구에서는 이러한 문제를 보완하기 위해 지역빈도해석을 이용하여 미래 전망 자료가 없는 지점들의 확률강우량을 추정하였다. 지역빈도해석을 수행하기 위해서는 관측 자료가 있는 유역내 지점들의 특성치(site characteristics)를 바탕으로 지역을 구분하고, Hosking and Wallis(1997)가 제안한 이질성 척도(heterogeneity measure)를 근거로 구분된 지역의 수문학적 동질성 여부를 검토하며, 각 지역에 대한 성장곡선(growth curve)를 추정한다. 지역별로 추정된 성장곡선에 지점의 연최대값 평균을 곱하면 그 지점의 확률강우량을 추정할 수 있다. 따라서 미래 기간의 지역별 성장곡선과 지점의 연최대값 평균을 전망할 수 있으면, 미래 기간의 지점별 확률강우량을 산정할 수 있고, 이를 바탕으로 확률홍수량도 전망할 수 있다. 이를 위해 본 연구에서는 전지구 모델에서 모의된 강우 자료를 바탕으로 미래 기간의 성장곡선을 추정하고, 과거 대비 미래 기간의 지속기간별 연최대값 평균의 비율을 산정하여 모의 자료가 없는 지점에 적용함으로써 미래 기간의 연최대값 평균을 산정하였으며, 이를 바탕으로 미래 기간의 확률강우량을 산정하도록 하였다. 이 기법의 신뢰도를 검증하기 위해 관측 자료를 두 기간으로 구분하여, 이 기법을 적용하여 추정한 확률강우량과 관측 자료로부터 산정한 확률강우량을 비교하였다.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.5
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• pp.713-719
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• 2009

In this paper, we develope a water demand forecasting algorithm using AR(Auto-regressive) and MLP(Multi-layer perceptron). To show effectiveness of the proposed method, we analyzed characteristics of time-series data collected in "A" purification plant at Jeon-Buk province during 2007-2008, and then performed the proposed method with various input factors selected through various analyses. As noted in experimental results, the performance of three types model such as multi-regressive, AR(Auto-regressive), and AR+MLP(Auto-regressive + Multi-layer perceptron) show 5.1%, 3.8%, and 3.6% with respect to MAPE(Mean Absolute Percentage Error), respectively. Thus, it is noted that the proposed method can be used to predict short-term water demand for the efficient operation of a water purification plant.

• The Journal of Engineering Geology
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• v.31 no.1
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• pp.19-30
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• 2021

This study evaluated the injection rate and the injection efficiency of the artificial recharge in the upper drought-prone watershed region, where the remaining water was used for injection, by using a numerical model to secure water during a drought. As a result of a numerical model under the condition of diverse injection rates per a well and hydraulic characteristics of the aquifer, the optimal injection rate per a well was estimated as 50.0 ㎥/day, and the injection efficiency was simulated as 33.2% to 81.2% of the total injection volume. As the injection time was shorter, the injection efficiency tented to increase non-linearly. As the injection rate increased, the residual storage in aquifer increased and available groundwater amount also increased, which could be advantageous for drought relief. For a more accurate assessment of injection efficiency, the model will be validated using the field injection data and optimum scenarios will enable the efficient operation of the artificial recharge system in the study area.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.4
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• pp.402-410
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• 2022

The present study introduces a calibration method of the CSC model implemented in the LS-DYNA program for considering the material properties of ultra-high performance concrete(UHPC). Based on previous experimental studies, various parameters, which constitute three shear failure surfaces, pressure-volumetric strain curve, fracture energy, dynamic increase factor(DIF), and so on, are modified. Then, the proposed calibration method is verified by comparing the numerical result with the experimental data through the single element analysis. In addition, based on the established finite element models, the applicability of the calibrated CSC model is examined for UHPC structures subjected to impact and blast loadings.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.973-991
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• 2022

Globally, several countries with sea are using eco-friendly energy resources through offshore wind power development by overcoming the weak point of the existing power generation method. The sea has the advantage of being able to develop large scale wind farms in wide waters, but the installation of marine structures threatens the safe operation of vessels. Accordingly, a standard guideline for safe navigation by analyzing the mutual effects between ship routes and offshore wind site was presented by the PIANC. Nonetheless, the standard guideline calculated the same safe distance in all situations. Therefore, this study developed a calculation model for an optimal safe distance between ship routes and offshore wind sites by reflecting the ship's maneuvering, encounter situations, environmental force, traffic density, offshore wind power generators, and channel types. As a result of the validation simulation, the developed model showed that the optimal safe distance was secured.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.71-71
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• 2023

국가물관리기본법에 의거하여 통합물관리 정책에 부합하는 농어촌용수 계획 및 관리를 위해 유역 및 용수구역 단위의 농업용수 공급 및 수요 분석이 요구되고 있다. 현재 농업용수는 개수로 방식 용수공급체계 및 수문 직접조작에 의한 용수배분체계로 공급량 대비 사용량의 비율이 48%에 불과하다. 또한, 농경지 상류와 하류의 공급량 차이가 크게 발생하며, 경지면적 감소가 공급 필요량 감소로 연결되지 않는다. 농업용수의 경우 기존 국가유역수자원 모델 (K-WEAP, MODISM)을 통한 물수지 분석시 순물소모량 개념의 회귀수량 산정으로 공급량과 회귀량의 왜곡이 발생하고 있으며, 이에 따른 공급량 왜곡, 유역내 복잡하고 다양한 농업용수 공급체계를 하나의 가상저수지로 단순화함으로서 유역내 들녘별 농업용수 과부족 분석 불가능, 하천과 저수지 공급 우선순위 현장과 불일치 등 농어촌용수구역의 특성 및 실제 현장을 반영하는데 한계가 있다. 본 연구에서는 기존 물수지 분석 모델을 개선하기 위한 농업용수 유역 물수지 분석 모델의 방법론을 제시하고 시범지역 적용을 통한 검증 및 적용성을 평가하고자 한다. 경기 안서 농촌용수구역을 대상으로 농어촌공사 및 지자체 관리 저수지, 양수장, 취입보, 관정 등 총 106개 개별 시설물 자료를 구축하였으며, 39개 지구로 세분화하였다. 한국농어촌공사의 계측 공급량 기반 수요량 및 개별 시설물에 대한 물수지 분석 후 지구 단위, 소유역 단위, 표준유역 단위의 상하류 및 시설물을 연계한 유역 물수지 모델을 제시하고자 한다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.2 s.54
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• pp.115-121
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• 2009

The paper presents a signal-based damage detection algorithm of ARX model using dynamic acceleration data. An ARX model correlates acceleration data measured at two locations in a structure by considering those two sets of data as input and output signals. For detecting damage, the error between the measured data and the predicted response from the defined ARX model is computed in time and used for a statistical evaluation. A normal distribution function from the error in time is constructed and its statistical characteristic values are used for the evaluation of damage. By comparing the normal distribution functions before and after damage, three different types of damage indices are proposed. The efficiency and limitation of the proposed algorithm with the statistical evaluation of damage indices have been examined and discussed through laboratory experiments.

• Journal of vocational education research
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• v.30 no.4
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• pp.23-49
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• 2011

Faculty performance evaluation system has been settled down as an uncomfortable but unavoidable system, and it is one of the most important factors to grow the college competitiveness up. In this study, we selected and surveyed faculty evaluation models of several universities and colleges in Korea, and analyzed by comparing each evaluation areas of educational achievement, college-industry collaboration, research, and service. We also identified the properties of the current faculty evaluation models of the junior colleges, and derived several problems from these models such as an imitation of four-year university model, a disorders of job evaluation with respect to the attributes of classified jobs, a large variation of individual item weights, and an insufficient reflection of major characteristics. Based on these surveys and analysis, an improved faculty evaluation model for the junior college is proposed in this study. This model proposed four basic areas-educational achievement, college-industry collaboration, research, and service by considering the importance of the college-industry collaboration in the junior college-as well as the team evaluation area. Weights of the SCI-class paper was selected as a criterion for the arrangement of objective comparison of each evaluation items. We showed the integration method of several different evaluation model with respect to the attributes of classified jobs of each faculties, and evaluation plan of variational characteristics according to the majors of individuals in this model. Finally, we introduced an area fail and rating system to operate efficiently the proposed faculty evaluation model.

• Information Systems Review
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• v.7 no.2
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• pp.41-59
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• 2005

Mobile games have emerged as the most innovative entertainment technology adding new revenue streams, taking advantage of the potential of wireless consumer applications and service offerings. Mobile games, like any other types of computer game, offer a unique value for users in providing an exciting digital experience in virtual worlds. Players can become empowered through the development of new characters and strategies within games to achieve rewarding successes against the computers and other players. In this paper, we attempt to investigate the factors influencing the usage and acceptance of the mobile games in Korea, based on the extended version of the Technology Acceptance Model(TAM). Based on data collected from survey, we show that perceived usefulness is the major determinant for users to play mobile games. Two factors, including perceived enjoyment and self-expressiveness, are empirically shown to determine perceived usefulness. In addition, perceived ease of use, rewards, operational quality of device, and design/story have been showed to significantly and directly affect perceived enjoyment. It was also confirmed that self-efficacy and operational quality of device are the antecedents of perceived ease of use. Based upon the statistical results, some useful guidelines for game development and market penetration strategies are also provided.