• 상하수도학회지
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• 제34권6호
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• pp.503-512
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• 2020

Identifying the water circulation status is one of the indispensable processes for watershed management in an urban area. Recently, various water circulation models have been developed to simulate the water circulation, but it takes a lot of time and cost to make a water circulation model that could adapt the characteristics of the watershed. This paper aims to develop a water circulation state estimation model that could easily calculate the status of water circulation in an urban watershed by using multiple linear regression analysis. The study watershed is a watershed in Seoul that applied the impermeable area ratio in 1962 and 2000. And, It was divided into 73 watersheds in order to consider changes in water circulation status according to the urban characteristic factors. The input data of the SHER(Similar Hydrologic Element Response) model, a water circulation model, were used as data for the urban characteristic factors of each watershed. A total of seven factors were considered as urban characteristic factors. Those factors included annual precipitation, watershed area, average land-surface slope, impervious surface ratio, coefficient of saturated permeability, hydraulic gradient of groundwater surface, and length of contact line with downstream block. With significance probabilities (or p-values) of 0.05 and below, all five models showed significant results in estimating the water circulation status such as the surface runoff rate and the evapotranspiration rate. The model that was applied all seven urban characteristics factors, can calculate the most similar results such as the existing water circulation model. The water circulation estimation model developed in this study is not only useful to simply estimate the water circulation status of ungauged watersheds but can also provide data for parameter calibration and validation.

• 지식경영연구
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• 제14권3호
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• pp.1-13
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• 2013

This study investigates how relational activities within MNC network affect knowledge transfer and performance of subsidiary. We separated the possible relationships between headquarter and overseas subsidiaries by support level, interaction level, and conflict level, and compared the impact on knowledge transfer, and performance. To understand the knowledge sharing, development and performance, we use structural equation modeling to analyze data from subsidiaries in China.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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• pp.164-165
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• 2016

To express the original texture of the concrete, exposed concrete finishing technique has been applied in many buildings. However, it is likely to cause quality problems after construction is completed. In addition, because of costs and time issues, reconstruction and maintenance works are difficult and ineffective. Therefore, step-by-step proactive quality management based on sufficient consensus among participants(client, designer, contractor) is very importatnt. This study analyzed factors causing low quality exposed concrete and quality contol points applied to 'A' headquarter construction project.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권7호
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• pp.34-42
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• 2015

Feasibility tests for the hydraulic fracturing were conducted in order to secure additional saline groundwater for irrigating to the land-based aquaculture farm. Two boreholes were placed to the aquaculture farm A and B, respectively. A hydraulic fracturing using single packer was applied to major fracture zones within two boreholes. To identify effects of hydraulic fracturing on securing additional saline groundwater, some selective methods including well logging methods, pumping tests, and groundwater quality analysis were commonly applied to the boreholes before and after the hydraulic fracturing. Enlarging/creating fracture zones, increasing water contents in bedrock near boreholes, and increasing transmissivity were observed after the hydraulic fracturing. Even though the hydraulic fracturing could be an alternative to secure additional saline groundwater to the land-based aquaculture farm, salinity of the groundwater did not meet optimal thresholds for each fingerling in two farms: Fresh submarine groundwater discharge flowed the more into borehole of the farm A that resulted in decreasing a salinity value. Increased saline groundwater quantity in the borehole of the farm B rarely affect to the salinity. Although salinity problem of groundwater limited its direct use for the farms, the mixing with seawater could be effectively used for the fingerlings during the early stage. A horizontal radial collector well placed in the alluvial layer could be an alternative for the farms as well.

• 한국농공학회논문집
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• 제62권3호
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• pp.71-83
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• 2020

Resilience is the capacity to maintain essential services under a range of circumstances from normal to extreme. It is achieved through the ability of assets, networks, systems and management to anticipate, absorb and recover from disturbance. It requires adaptive capacity in respect of current and future risks and uncertainties as well as experience to date. The agricultural infrastructures with high resilience can not only reduce the size of the disaster relatively, but also minimize the loss by reducing the time required for recovery. This study aims to evaluate the most suitable drought countermeasures with the analysis of various resilience indices by predicting future agricultural water shortage under land use and climate change scenarios for agricultural areas in Jeju Island. The results showed that the permanent countermeasure is suitable than the temporary countermeasures as drought size and the cost required for recovery increase. Wide-area water supply system, which is a kind of water grid system, is identified as the most advantageous among countermeasures. It is recommended to evaluate the capability of agricultural infrastructure against drought with the various Resilience Indices for reliable assessment of long-term effect.

• 한국지하수토양환경학회지:지하수토양환경
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• 제16권2호
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• pp.41-51
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• 2011

This study was conducted to investigate the relationship between groundwater level change and a large earthquake using the data of groundwater and seawater intrusion monitoring wells in Jeju Island. Groundwater level data from 13 observation wells were analyzed with a large earthquake. The Earthquake occurred at Sumatra, Indonesia (Mw = 7.7) on 13 June 2010, and groundwater level anomalies which seems to be related to the Earthquake were found in 6 monitoring wells. They lasted for approximately 16~27 minutes and the range of groundwater level fluctuations were about 1.4~2.4 cm. Coefficient of determination values for relationship between groundwater level change and transmissivity, and response time were calculated to be $R^2$ = 0.76 and $R^2$ = 0.96, respectively. The study also indicates that the high transmissivity of aquifer showed the high goundwater level changes and longer response time.

• 정보화연구
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• 제11권3호
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• pp.311-320
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• 2014

본 연구의 목적은 본사와 지사의 유연성이 글로벌 ERP 시스템의 구축 성과에 미치는 영향을 이해하는 것이다. 구체적으로 본 연구의 질문은 다음과 같다. 첫째, 글로벌 ERP 시스템 구축과 관련이 있는 본사와 지사의 유연성 차원에는 무엇이 있는가? 둘째, 이들 유연성 차원들 각각이 글로벌 ERP 시스템 구축 성과에 미치는 영향은 어떠한가? 본 연구는 이론적 검토를 통해 글로벌 ERP 시스템 구축과 관련이 있는 본사가 갖추어야 할 3가지 유형의 유연성과 지사가 갖추어야 할 3가지 유형의 유연성을 제시하였다. 그리고 본 연구는 글로벌 기업인 보그워너(BorgWarner)를 사례기업으로 선정하고 이 기업이 글로벌 ERP 시스템을 성공적으로 구축하는데, 어떤 유연성 요인이 성과에 기여하였는지를 사례 조사하였다.

• 한국통신학회논문지
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• 제39C권8호
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• pp.667-673
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• 2014

스마트 조선소는 조선소 내 여러 사이트에서 제작되는 모듈부터 최종통합하기까지의 모든 업무를 모바일 애플리케이션을 이용하여 현장에서 바로 처리 가능하게 한다. 본 논문에서는 하위조선소에 적용할 수 있는 LTE 펨토셀 네트워크 구성과 상위조선소와 중요정보를 주고받는 트래픽을 주고받기 위한 일반 트래픽을 분리하는 오프로드 방식을 제안하였다. 상위 조선소의 메인서버와 하위 조선소 간에 정보와 일반 트래픽의 오프로드를 지원하기 위한 펨토셀 게이트웨이에서의 모드전환, 오프로드 관련 정보 관리, 관련 메시지를 정의하였다. 제안한 방안을 통해 무선구간에서의 과부화된 트래픽을 최적화된 경로로 보낼 수 있는지 기능 수행여부를 송수신 메시지 플로우와 state transition diagram을 이용하여 확인하였다. 우리는 이동통신망과 LTE 펨토셀 네트워크를 스마트 조선소내에 적용하여 조선소 업무와 생산성 향상이 기대된다.

• 대한토목학회논문집
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• 제31권5D호
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• pp.641-648
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• 2011

교통관리업무에서는 교통관리지원 장비뿐만 아니라 교통관리자 개인의 판단, 지식의 역량 등 인적요소에 의하여 교통성과의 차이가 난다. 따라서 특정조직에서 교통관리 소속원의 자기평가는 교통관리조직의 성과진단 혹은 상태진단을 하는 간접도구로 사용될 수 있다. 본 논문은 국내 다양한 교통관리집단과 일본특정교통관리집단의 자기평가를 통하여 국내 특정 도시간선도로관리기관의 교통관리 상태를 평가하여 적정성을 검토하는 것을 목적으로 하였다. 그 결과로서 국내 간선도로관리집단의 조직이 성과, 활동, 미래지향성, 고객 지향성 등에서 다른 집단 보다 우수한 것으로 나타났다. 그 집단에 대하여 근무지별로 상세 평가를 하였다. 근무지별로는 본부, 지역본부, 현장, 정보센타, 연구원으로 구분하였다. 근무자들은 소속된 근무지의 교통관리 특성에 맞게 다양한 교통관리 요소의 개선 필요성을 제시하였다.

• 한국물환경학회지
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• 제20권4호
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• pp.357-364
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• 2004

In this study, biodegradable organic matter was divided into a rapidly biodegradable fraction($BDOC_{rapid}$) and a slowly biodegradable fraction($BDOC_{slow}$) for various waters with different types of DOC. These fractions($BDOC_{rapid}$ and $BDOC_{slow}$) were defined by using a shaking incubation method modified from Carlson's method. Also, in this study, optimum incubation time and accuracy were investigated to determine $BDOC_{rapid}$ and $BDOC_{slow}$. When suspended bacteria obtained from raw water and BAC effluent, or attached bacteria from BAC was respectively used as an inoculum, the difference in total BDOC($BDOC_{total}$) was minimal. Therefore, total BDOC was determined in 7~8 days by the shaking method, which is comparable with Servais's method by which BDOC was determined in 28 days. In addition, the difference of BDOC between these two methods was within 7%. Although $BDOC_{rapid}$ and $BDOC_{slow}$ were effectively determined by a method defined by Klevens, the difference in optimal incubation time was significant for different water samples. However, when using the shaking method, optimal incubation time for $BDOC_{rapid}$ was found to be 3 days, therefore, the $BDOC_{rapid}$ was defined as the difference between $DOC_0$ and $DOC_{3days}$, and $BDOC_{slow}$ was defined as the difference between $BDOC_{total}$ and $BDOC_{rapid}$. As a conclusion, for determining the fraction of BDOC using the shaking method, the concentrations of an inoculurns and optimal incubation times used in this study were very effective.