• Membrane and Water Treatment
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• 제10권1호
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• pp.75-82
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• 2019

In a highly urbanized area, land availability is limited for the installation of space consuming stormwater systems for best management practices (BMPs), leading to the consideration of underground stormwater treatment devices connected to the stormwater pipe system. The configuration of a stormwater pipe network determines the hydrological and pollutant transport characteristics of the stormwater discharged through the pipe network, and thus should be an important design consideration for effective management of stormwater quantity and quality. This article presents a multi-objective optimization approach for designing a stormwater pipe network with on-line stormwater treatment devices to achieve an optimal trade-off between the total installation cost and the annual removal efficiency of total suspended solids (TSS). The Non-dominated Sorted Genetic Algorithm-II (NSGA-II) was adapted to solve the multi-objective optimization problem. The study site used to demonstrate the developed approach was a commercial area that has an existing pipe network with eight outfalls into an adjacent stream in Yongin City, South Korea. The stormwater management model (SWMM) was calibrated based on the data obtained from a subcatchment within the study area and was further used to simulate the flow rates and TSS discharge rates through a given pipe network for the entire study area. In the simulation, an underground stormwater treatment device was assumed to be installed at each outfall and sized proportional to the average flow rate at the outfall. The total installation cost for the pipes and underground devices was estimated based on empirical formulas using the flow rates and TSS discharge rates simulated by the SWMM. In the demonstration example, the installation cost could be reduced by up to 9% while the annual TSS removal efficiency could be increased by 4% compared to the original pipe network configuration. The annual TSS removal efficiency was relatively insensitive to the total installation cost in the Pareto-optimal solutions of the pipe network design. The results suggested that the installation cost of the pipes and stormwater treatment devices can be substantially reduced without significantly compromising the pollutant removal efficiency when the pipe network is optimally designed.

• 한국중재학회지:중재연구
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• 제30권4호
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• pp.121-138
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• 2020

The O2O services in the healthcare sector have only been in full swing for about three years, and unlike existing O2O consumer goods, the scale and scope of the dispute are more complicated due to restrictions on medical treatment. In this study, O2O service platform operators and medical institutions' roles and responsibilities were redefined as a countermeasure for resolving disputes in healthcare O2O services and the laws for changing the transaction environment. A change in institutional mechanisms was proposed. This study looked at the types of consumer disputes related to healthcare O2O services as insufficient information problems, problems in the course of medical service implementation, problems with immunity provisions for platform operators, cancellations, and non-compliance with refunds. All the information generated during transactions in the healthcare sector was extensive in scale and included the most sensitive information among personal information, stressing the importance of ensuring security. The area that started in the O2O range before the medical institution visit also proposed a plan to establish a system for the delivery of proven information as a pre-medical person. The scale and growth will grow faster, given that consumers can experience the information they want anytime, anywhere they want. However, the platform broker's role, a link player, will become more important because consumers who use the service will have their first meeting with non-face-to-face product providers. On the other hand, service providers may have side effects of misleading consumers by providing false information or misleading consumers through exaggerated advertisements. The O2O service market is expected to expand beyond distribution and dining out to the entire industry. However, since it is challenging to check accurate statistics on the detailed market, various disputes and consumer protection measures will be required for each detailed market, and comprehensive leading solutions will be essential in the future.

• 한국인터넷방송통신학회논문지
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• 제23권6호
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• pp.9-14
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• 2023

정보시스템 감리의 목적은 정보시스템 구축 과정에서 발생하는 모든 위험 요소를 선제적으로 발견하고 이를 효율적으로 관리하여 정보시스템 개발 목적을 달성하고자 하는 것이다. 그러나 감리 현장에서는 정보시스템 감리 과정에 대한 품질 및 효과에 대하여 많은 불만을 표출하고 있어, 이에 대한 문제 해결을 통해 정보시스템의 효과적이고 효율적인 구축에 실질적인 도움이 되도록 하는 방법에 관하여 많은 연구가 진행되고 있다. 본 논문에서는 감리인과 평가자 모두에게 상호 이해가 가능하도록 다단계 감리평가 모델을 제안하여, 각 단계의 품질 레벨을 향상시키는 성숙화 과정을 거치는 모델을 제시하였다. 성숙도에 기반한 이 평가 모델 플랫폼은 감리인과 평가자 상호 간의 협의를 통해 효율적으로 개선사항을 도출하고 실시간 검색을 통해 이를 시정하여 전체 시스템을 성숙화하는 다단계 모델로서 정보시스템 구축과 정을 효율적으로 관리하고자 하는 것이 주 목적이다.

• Geomechanics and Engineering
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• 제36권3호
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• pp.217-229
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• 2024

Determining lateral earth pressure coefficient (EPC) K is a classic problem in geotechnical engineering. It is a key parameter for estimating the stresses in backfilled openings. For backfilled openings with rigid and immobile walls, some suggested using the Jaky's at-rest earth pressure coefficient K₀ while other suggested taking the Rankine's active earth pressure coefficient K_a. A single value was proposed for the entire backfilled opening. To better understand the distributions of stresses and K in a backfilled opening, a series of laboratory tests have been conducted. The horizontal and vertical normal stresses at the center and near the wall of the opening were measured. The values of K at the center and near the wall were then calculated with the measured horizontal and vertical normal stresses. The results show that the values of K are close to K_a at the center and close to K₀ near the wall. Furthermore, the experimental results show that the horizontal stress is almost the same at the center and near the wall, indicating a uniform distribution from the center to the wall. It can be estimated by analytical solutions using either K_a or K₀. The vertical stress is higher near the center than near the wall. Its analytical estimation can only be done by using K_a at the center and K₀ near the wall. Finally, the test results were used to calibrate a numerical model of FLAC2D, which was then used to analyze the influence of column size on the stresses and K in the backfilled opening.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2017년도 춘계학술발표대회
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• pp.595-597
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• 2017

세계 SW시장은 급성장하고 있지만, 국내시장이 글로벌 강국에 영향을 주기에는 많이 부족하다. 인터넷 속도 1위국임에도 SW성장이 더딘 이유는 무엇일까? 그것은 국내 SW산업발전의 기반이 마련되지 않았기 때문이다. 이로써 정부는 SW중심사회를 선언하여 각 분야의 정책을 준비하였는데 공공부문 SW분할발주 제도를 IT프로젝트에 적용하려는 움직임이 있어 전체 SW산업의 약 30%를 차지하는 공공부문을 중심으로 SW분할발주 제도 시행시 예상되는 SI프로젝트 문제점 및 개선방안을 연구하고자 한다. SW분할발주 제도는 기획~설계와 개발~구현 단계로 구분됨에 따라 SI프로젝트에 적용함에 있어 문제가 발생될 수 있다. 그러므로 프로젝트와 분리 분할발주, 선진사례 및 분할발주 유관산업 프로젝트 사례를 분석하였으며 제도적, 기술적, 관리적 관점에서 개선방안을 도출하였다. 본 논문은 IT프로젝트에 종사하는 이들의 SW제값받기 및 환경개선을 기대하고 SW분할발주의 제도 시행 전 공급자와 수요자가 인식해야 하는 문제점에 대한 해결방안을 제공하여 SW산업과 SI프로젝트의 경쟁력을 강화하는 체계 형성의 방향을 제시한다.

• 한국의료질향상학회지
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• 제8권1호
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• pp.10-21
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• 2001

Background : The Clostridium difficile is the most important identifiable cause of nosocomial infectious diarrhea and colitis, which lengthens hospital stay. Recently incidence of C. difficile has been increasing in an university hospital, and an intervention for prevention and control of C. difficile associated diarrhea (CDAD) was in prompt need. Methods : Subjects were the patients in the neurosurgical intensive care unit(NCU) where C. difficile was most frequently isolated. To increase participation of various departments, we used the CQI method, because management of CDAD requires a wholistic approach including control of antibiotics, barrier precaution and environmental cleaning and disinfection. Duration of the CQI activities was 9 months from April to December 1999. Results : The identified problems were misuse and overuse of antibiotics, lack of consciousness of medical personnels and the possibility of transmission from the contaminated environment and tube feeding. Education for proper use of antibiotics and management of C. difficile infection, use of precaution stickers, supplement of handwashing equipments, emphasis on environmental disinfection, and the change of the process of tube feeding were done. The CDAD rate in NCU was significantly decreased after the CQI program (8.6 case per 1,000 patient days from January to April 1999 vs 4.8 from May to December 1999). The distribution of neurosurgical wards including NCU among the total number of isolated C. difficile from the clinical specimens dropped from 49.4% in January to April to 33,7% in May to December. The average hospital stay of the neurosurgical department changed from 19.6 days to 15.2 days. Also, the effect of the CQI activities for C. difficile may have affected the incidence of vancomycin resistant enterococci (VRE). Duration and dosage of certain antibiotics used in the NS department were decreased. The distribution of neurosurgical department in the number of VRE isolated patients declined from 18.4% to 11.1%. Conclusion : Infection control of resistant organisms such as C. difficile is likely to be successful when management of environmental contamination an collaborative efforts of decreasing the patients' risk factors such as antibiotics management and decreasing the length of hospital stay come simultaneously. For this work, related departments need to actively participate in the entire process under a common target through discussions for identifying problems and bringing up solutions. In this respect, making use of a CQI team is an efficient method of infection control for gathering participation and cooperation of related departments.

• 유통과학연구
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• 제13권11호
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• pp.123-130
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• 2015

Purpose - Due to highly elevated levels of competition, many companies today have to face the problem of decreasing profits even when their actual sales volume is increasing. This is a common phenomenon that is seen occurring among companies that focus heavily on quantitative growth rather than qualitative growth. These two aspects of growth should be well balanced for a company to create a sustainable business model. For supply chain management (SCM) planners, the optimized, quantified flow of resources used to be of major interest for decades. However, this trend is rapidly changing so that managers can put the appropriate balance between sales volume and sales quality, which can be evaluated from the profit margin. Profit optimization is a methodology for companies to use to achieve solutions focused more on profitability than sales volume. In this study, we attempt to provide executional insight for companies considering implementation of the profit optimization system to enhance their business profitability. Research design, data, and methodology - In this study, we present a comprehensive explanation of the subject of profit optimization, including the fundamental concepts, the most common profit optimization logic algorithm -linear programming -the business functional scope of the profit optimization system, major key success factors for implementing the profit optimization system at a business organization, and weekly level detailed business processes to actively manage effective system performance in achieving the goals of the system. Additionally, for the purpose of providing more realistic and practical information, we carefully investigate a profit optimization system implementation case study project fulfilled for company S. The project duration was about eight months, with four full-time system development consultants deployed for the period. To guarantee the project's success, the organization adopted a proven system implementation methodology, supply chain management (SCM) six-sigma. SCM six-sigma was originally developed by a group of talented consultants within Samsung SDS through focused efforts and investment in synthesizing SCM and six-sigma to improve and innovate their SCM operations across the entire Samsung Organization. Results - Profit optimization can enable a company to create sales and production plans focused on more profitable products and customers, resulting in sustainable growth. In this study, we explain the concept of profit optimization and prerequisites for successful implementation of the system. Furthermore, the efficient way of system security administration, one of the hottest topics today, is also addressed. Conclusion - This case study can benefit numerous companies that are eagerly searching for ways to break-through current profitability levels. We cannot guarantee that the decision to deploy the profit optimization system will bring success, but we can guarantee that with the help of our study, companies trying to implement profit optimization systems can minimize various possible risks across various system implementation phases. The actual system implementation case of the profit optimization project at company S introduced here can provide valuable lessons for both business organizations and research communities.

• 산업경영시스템학회지
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• 제35권2호
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• pp.57-63
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• 2012

소프트웨어 개발에 있어서 소프트웨어를 시장에 출시하는 계획을 수립하는 것은 소프트웨어를 이루고 있는 기능들을 구현하는 데 제약이 되는 조건들(기술, 자원, 위험, 예산 등)을 만족하면서 계획된 출시기간에 이들 기능들을 할당하는 일이다. 이와 같이 소프트웨어 출시를 계획하는 것은 소프트웨어 제품라인에 대해서 고려할 때 더욱 복잡해진다. 본 연구에서는 소프트웨어 제품라인에 있어서 소프트웨어 출시 계획을 수립하기 위한 문제를 우선순위 제약하의 다수 0-1 배낭문제로 수리 모형화하고, 이를 풀기 위한 최적해법이 개발된다. 최적해법은 동적 계획법이 주가 되고, 문제의 크기를 줄이기 위하여 휴리스틱과 축소방법이 이용된다.

• 대한전자공학회논문지SD
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• 제48권9호
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• pp.22-30
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• 2011

최근 카메라를 통해 입력된 영상정보로부터 실시간으로 상황을 인지하고 자율 대응할 수 있는 지능형 영상 보안 시스템의 수요가 증가함에 따라, 고성능의 얼굴 인식 시스템이 요구되고 있다. 기존의 얼굴 인식 시스템의 성능 향상을 위해서는 원거리에서 획득된 저해상도 얼굴 영상 처리를 위한 솔루션이 반드시 필요하다. 따라서 본 논문에서는 실시간 감시가 요구되는 지능형 영상 보안 시스템의 얼굴 인식 성능 향상을 위한 저해상도 얼굴 영상 복원 알고리즘을 하드웨어로 구현하였다. 저해상도 얼굴 영상 복원 방법으로는 학습 기반의 초해상도 알고리즘을 사용한다. 해당 알고리즘은 먼저 고해상도 영상으로 구성된 학습 집합에서 주성분 분석(PCA)을 활용하여 복원에 필요한 사전 정보들을 추출하고, 저해상도 영상과의 관계를 모델링하여 가장 적합한 고해상도 얼굴을 복원해내는 것이다. 저해상도 얼굴 영상 복원 알고리즘을 임베디드 프로세서(S3C2440A)를 사용하여 구현하였을 때, 약 25 초의 긴 연산 시간이 소요되었다. 이는 실시간으로 사람을 판별 및 인식하기 위한 지능형 영상 보안 시스템의 구축에는 어려움이 있다. 이를 해결하기 위하여 얼굴 영역 초해상도의 연산을 하드웨어로 구현하고 Xilinx Virtex-4를 이용하여 검증하였다. 약 9MB의 학습 데이터를 사용하였으며, 100 MHz에서 약 30 fps의 속도로 연산이 가능하다. 이러한 학습 기반의 얼굴 영역 초해상도 알고리즘을 단일 하드웨어 IP로 설계함으로써 임베디드 환경에서의 실시간 처리가 가능할 뿐 만 아니라 기존의 다양한 얼굴 검출 시스템과의 통합이 용이하여 얼굴 인식 솔루션을 제공할 수 있을 것으로 판단된다.

• 한국전자파학회논문지
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• 제23권1호
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• pp.96-100
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• 2012

정 자장($B_0$)의 세기가 7 T(Tesla) 또는 9.4 T 고자기장 MRI(Magnetic Resonance Imaging) 시스템은 정 자장의 세기가 1.5 T 또는 3 T MRI(Magnetic Resonance Imaging) 시스템에 비하여 인가된 RF(Radio Frequency) 필드의 높은 불균질성을 보여준다. 다채널(multi-channel) RF 코일에서는 인가된 RF 자장($B_1^+$)의 불균질성을 개선시키기 위해서 각각의 코일 소자(element)에 인가되는 전류의 크기와 위상을 독립적으로 조절할 수 있다. 선택된 관심 영역에서의 RF 자장이 균일하도록 RF 코일의 각 요소로 들어가는 최적화된 전류의 크기와 위상 값을 얻기 위해서 iterative 방법과 함께 convex 최적화 방법이 사용된다. 이러한 방법을 입증하기 위하여 9.4 T MRI 시스템에 RF 코일의 공진 주파수가 400 MHz을 가지는 다채널 전송 선로 코일이 인체 두상 모형과 함께 모델링되었으며, 이 코일에 의하여 자장이 얻어진다. 9.4 T MRI 시스템을 위한 시뮬레이션 결과가 자세히 논의된다.