• 가족자원경영과 정책
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• 제15권3호
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• pp.131-151
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• 2011

This study attempted to estimate the level of perceived lack of time in Korean society, to link it to time management and to identify the possible association that accounts for time shortage. I employed the gender perspective in order to reveal the dynamics and complexity of the perception of a lack of time in the population. The sample for the study was drawn from the 1999 and 2009 Korean time diary data collected by the Korean National Statistical Office. From the original data, I selected a sample of second shift families(men and women who are presently working and raising children) living in metropolitan areas(including Seoul and six major urban areas in Korea). The dependent variable was time pressure measured by a single-item question on a four-point likert scale. The results of the study showed that working mothers perceived a greater time shortage as compared to working fathers. The time use pattern showed change during the periods, indicating that people worked fewer hours in paid labor and enjoyed more leisure hours and personal care hours. However, on average, people seemed to have experienced a greater time lack in 2009 as compared to 1999. The results from the ordered logistic regression model revealed that even though there were similarities in the impact of relevant factors, men's perception of a lack of time was more closely linked with their work role and social status, while for women, this perception was influenced by work and family duties. This indicates that Korean working mothers and fathers are facing a double jeopardy of time shortage in terms of combining their work and family roles. As a result, the level of time pressure by gender is converging toward a "never enough" phase. These findings generated policy implications and detailed suggestions.

• 정보과학회 컴퓨팅의 실제 논문지
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• 제23권1호
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• pp.45-56
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• 2017

천문학 분야에서 광시야망원경을 통해 관측된 자료들의 양은 기하급수적으로 늘어나고 있다. 그러나 고정된 소규모의 컴퓨팅 환경과 자료 분석 도구들의 복잡성은 대용량 관측 자료들을 효율적으로 처리하는데 어려움을 야기한다. 본 논문에서는 이러한 문제점을 해결하기 위해, 대용량 천문 관측 자료처리를 위한 클라우드 기반의 자동화 시스템을 제안한다. 본 논문에서 제안한 시스템은 관측 자료 분석에 필요한 워크플로우 템플릿의 관리 및 실행 제어를 위한 워크플로우 실행 관리자(Workflow Execution Manager)와 관측 자료 분석 요청 량에 따라 동적으로 계산자원의 할당/반납이 가능한 탄력적 자원 관리자(Elastic Resource Manager)로 구성된다. 또한 동적 자원 할당 추이, 시스템 부하 등의 다양한 실험 및 결과 분석을 통해 제안한 시스템의 유효성을 검증하고, DEEP-SOUTH 스케쥴링 시스템에의 적용 사례를 기술한다.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2006년도 정기학술발표대회 논문집
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• pp.390-395
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• 2006

오늘날 건설수요는 고도화, 프로젝트의 대형화, 공사여건의 복잡화와 같은 외부환경에 의해 변하고 있다. 이에 정부에서는 외부환경의 변화에 적절히 대응하고자 선진화된 발주방식을 도입하였다. 그러나 이러한 의도와는 달리, 기 발주된 프로젝트에서는 발주방식별 장${\cdot}$단점 등이 효과적으로 나타나지 못하고 있다. 이러한 원인은 사업의 기획단계에서 발주방식을 선정할 때 사업의 특성을 충분히 반영하지 못하는 현재의 "대형공사 입찰방법 심의기준"에서 그 원인을 찾을 수 있다. 따라서 본 연구는 프로젝트의 특성에 따른 적절한 발주방식을 적용하기 위하여 발주방식 선정기준을 위한 모델을 제시하고자 한다.

• 한국산학기술학회논문지
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• 제19권9호
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• pp.501-507
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• 2018

무기체계의 복잡성과 현대화로 인해 군수품을 생산하는 방위산업체의 역할은 점점 더 중요시되고 있다. 과거 내수위주의 방위산업은 가격 경쟁력이 제품 선택의 주요 요소였다. 하지만, 오늘날 우수 품질을 바탕으로 국내 군수품에 대한 수출이 급속도로 확대되고 있는 실정이며 국내 방위산업체의 경영의 효율성을 객관적으로 평가할 수 있는 방안이 필요 시 되고 있다. 본 연구에서는 의사결정 방법론 중 하나인 자료포락분석기법(Data Envelopment Analysis, DEA)를 활용하여 경영효율성을 측정하고자 한다. 본 연구에서 DEA를 활용하기 위해 투입 변수로 종업원수(품질부서), R&D현황을 설정하였고 출력 변수로는 매출액 및 영업이익을 설정하였다. 방산업체의 효율성을 분석하기 위해 불면 규모수익을 가정하는 CCR(harnes, Cooper and Rhodes)모형과 수익변동모형을 가정하는 BCC(Banker, Charnes and Cooper)모형을 모두 분석하였으며 규모효율성(Scale Efficiency: SE) 값을 도출하여 비효율적인 DMU의 원인을 분석하였다. 분석 결과를 바탕으로 국내 방위산업체의 수준 평가 및 비효율적인 DMU의 원인을 분석하였으며 마지막으로 국내 방산업체의 발전 방안을 도출하였다.

• 품질경영학회지
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• 제45권4호
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• pp.629-648
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• 2017

Purpose: The world faces a great turning point fundamentally rebuilding the future, and human lives, by embracing the 4th industrial revolution era. This paper aims to seek new and various business models in the 4th industrial revolution era, and to examine the evolution of quality management in the changing of the industrial ecosystem. Methods: This paper examines the various strategies of approaching the 4th industrial revolution in Germany, the USA, Japan, China, and Korea. This paper also draws detailed items by classifying the six major items of Malcolm Baldridge into large, medium, and small scale classifications, researches items from the technical perspective by applied fields, and the four major factor perspectives of quality management, as well as analyzes the relevant items in a multidimensional method. After a questionnaire survey targeting 200 quality experts was conducted, the important quality management factors were selected by applying the Analytic Hierarchy Process (AHP) method. Results: The importance of the general criteria was analyzed in the order of customers, MAKM (measurement, analysis, and knowledge management), workforce, strategy, operations, and leadership. As for the importance analysis results of the secondary subcriteria, the following items are highly analyzed: senior leadership, searching business model's innovation opportunity, customer satisfaction improvement, big data utilization, systematic management of workforce, and, planning and design quality. Conclusion: In the era of the Internet of everything, when complexity increases, this study presented a quality management direction suitable for new business methods challenging existing orders by drawing on quality management priorities.

• 한국물환경학회지
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• 제23권6호
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• pp.951-960
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• 2007

Window interface to Hydrological Simulation Program-FORTRAN (WinHSPF) developed by the United States Environmental Protection Agency (EPA) was applied to the upstream of Nam-Han river watershed to examine its applicability for loading estimates in watershed scale and to evaluate non-point source control scenarios using BMPRAC in WinHSPF. The WinHSPF model was calibrated and verified for water flow using Ministry of Construction and Transportation (MOCT, 3 stations, 2003~2005) and water qualities using Ministry of Environment (MOE, 5 station, 2000~2006). Water flow and water quality simulation results were also satisfactory over the total simulation period. But outliers were occurred in the time series data of TN and TP at some regions and periods. Therefore, it required more profit calibration process for more various parameters. As a result, all the study was performed within the expectation considering the complexity of the watershed, pollutant sources and land uses intermixed in the watershed. The estimated pollutant load for annual average about $BOD_5$, T-N and T-P respectively. Nonpoint source loading had a great portion of total pollutant loading, about 86.5~95.2%. In WinHSPF, BMPRAC was applied to evaluate non-point source control scenarios (constructed wetland, wet detention ponds and infiltration basins). All the scenarios showed efficiency of non-point source removal. Overall, the HSPF model is adequate for simulating watersheds characteristics, and its application is recommended for watershed management and evaluation of best management practices.

• 한국측량학회지
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• 제25권6_1호
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• pp.545-555
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• 2007

3D buildings are the most prominent feature comprising urban scene. A few of mega-cities in the globe are virtually reconstructed in photo-realistic 3D models, which becomes accessible by the public through the state-of-the-art online mapping services. A lot of research efforts have been made to develop automatic reconstruction technique of large-scale 3D building models from remotely sensed data. However, existing methods still produce irregular building polygons due to errors induced partly by uncalibrated sensor system, scene complexity and partly inappropriate sensor resolution to observed object scales. Thus, a geometric regularization technique is urgently required to rectify such irregular building polygons that are quickly captured from low sensory data. This paper aims to develop a new method for regularizing noise building outlines extracted from airborne LiDAR data, and to evaluate its performance in comparison with existing methods. These include Douglas-Peucker's polyline simplication, total least-squared adjustment, model hypothesis-verification, and rule-based rectification. Based on Minimum Description Length (MDL) principal, a new objective function, Geometric Minimum Description Length (GMDL), to regularize geometric noises is introduced to enhance the repetition of identical line directionality, regular angle transition and to minimize the number of vertices used. After generating hypothetical regularized models, a global optimum of the geometric regularity is achieved by verifying the entire solution space. A comparative evaluation of the proposed geometric regulator is conducted using both simulated and real building vectors with various levels of noise. The results show that the GMDL outperforms the selected existing algorithms at the most of noise levels.

• 한국항공우주학회지
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• 제33권8호
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• pp.56-64
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• 2005

모형헬리콥터를 이용한 무인항공기 설계를 위해 비선형 형태의 수학적 모델이 선행되어야 한다. 모형헬리콥터는 실기 헬리콥터에 비해 회전수가 훨씬 높으며 따라서 동특성도 실물기에 비해 훨씬 빠르다는 차이점이 있다. 본 논문에서는 축소형 헬리콥터의 수학적 모델링에 필요한 정식화과정으로서 복잡성을 최소화하면서도 실제의 동특성에 잘 부합하도록 각 구성요소별로 계산한 후 전체로 합산하는 방법을 제시하였다. 제자리 비행과 전진비행에서 수치계산을 통해 트림 값들을 계산하고 제자리 비행조건에서 선형 시스템을 해석하여 모형헬리콥터의 비행모드를 분석하였다. 계산결과 일반적인 경향은 몇 가지 작은 부분 이외에는 대체로 다른 연구결과와 비슷하였다. 이 과정을 검증하기 위해서 비행시험을 수행하여 시스템식별에 의한 결과와 비교하는 연구가 후속 수행될 예정이다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제2권2호
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• pp.63-81
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• 2008

WiMAX has been introduced as a competitive alternative for metropolitan broadband wireless access technologies. It is connection oriented and it can provide very high data rates, large service coverage, and flexible quality of services (QoS). Due to the large number of connections and flexible QoS supported by WiMAX, the uplink access in WiMAX networks is very challenging since the medium access control (MAC) protocol must efficiently manage the bandwidth and related channel allocations. In this paper, we propose and investigate a cost-effective WiMAX bandwidth management scheme, named the WiMAX partial sharing scheme (WPSS), in order to provide good QoS while achieving better bandwidth utilization and network throughput. The proposed bandwidth management scheme is compared with a simple but inefficient scheme, named the WiMAX complete sharing scheme (WCPS). A maximum entropy (ME) based analytical model (MEAM) is proposed for the performance evaluation of the two bandwidth management schemes. The reason for using MEAM for the performance evaluation is that MEAM can efficiently model a large-scale system in which the number of stations or connections is generally very high, while the traditional simulation and analytical (e.g., Markov models) approaches cannot perform well due to the high computation complexity. We model the bandwidth management scheme as a queuing network model (QNM) that consists of interacting multiclass queues for different service classes. Closed form expressions for the state and blocking probability distributions are derived for those schemes. Simulation results verify the MEAM numerical results and show that WPSS can significantly improve the network’s performance compared to WCPS.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권2호
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• pp.709-730
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• 2017

To address the challenge of unprecedented growth in mobile data traffic, ultra-dense network deployment is a cost efficient solution to offload the traffic over some small cells. The overlapped coverage areas of small cells create more than one candidate access points for one mobile user. Signal strength based user association in IEEE 802.11 results in a significantly unbalanced load distribution among access points. However, the effective bandwidth demand of each user actually differs vastly due to their different preferences for mobile applications. In this paper, we formulate a set of non-linear integer programming models for joint user association control and user demand guarantee problem. In this model, we are trying to maximize the system capacity and guarantee the effective bandwidth demand for each user by soft-association control with a software defined network controller. With the fact of NP-hard complexity of non-linear integer programming solver, we propose a Kernighan Lin Algorithm based graph-partitioning method for a large-scale network. Finally, we evaluated the performance of the proposed algorithm for the edge users with heterogeneous bandwidth demands and mobility scenarios. Simulation results show that the proposed adaptive soft-association control can achieve a better performance than the other two and improves the individual quality of user experience with a little price on system throughput.