• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -2
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• pp.1327-1330
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• 2002

In this paper examines theoretical analysis of passive intermodulation and its methods of measurement and procedure. And based on the results of field measurement, it defines the reasons of passive intermodulation of base stations, suggests characteristics by device and methods of improvement to minimize the influence of a base station on passive intermodulation, and compares and analyzes the results of field measurement before and after the reasons are improved to secure the characteristics by device and the utility and adequacy of methods of improvement.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권11호
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• pp.3892-3912
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• 2021

The recent rapid growth of mobile network traffic places multi-access edge computing in an important position to reduce network load and improve network capacity and service quality. Contrasting with traditional mobile cloud computing, multi-access edge computing includes a base station cooperative cache layer and user cooperative cache layer. Selecting the most appropriate cache content according to actual needs and determining the most appropriate location to optimize the cache performance have emerged as serious issues in multi-access edge computing that must be solved urgently. For this reason, a cache placement algorithm based on comprehensive utility in big data multi-access edge computing (CPBCU) is proposed in this work. Firstly, the cache value generated by cache placement is calculated using the cache capacity, data popularity, and node replacement rate. Secondly, the cache placement problem is then modeled according to the cache value, data object acquisition, and replacement cost. The cache placement model is then transformed into a combinatorial optimization problem and the cache objects are placed on the appropriate data nodes using tabu search algorithm. Finally, to verify the feasibility and effectiveness of the algorithm, a multi-access edge computing experimental environment is built. Experimental results show that CPBCU provides a significant improvement in cache service rate, data response time, and replacement number compared with other cache placement algorithms.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1509-1514
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• 2009

CII BM&M(Benchmarking & Metrics) in USA and DTI(Department of Trade and Industry) in UK have built up systems that enable performance measuring and made the results of performance measurement comparable between projects to utilize them as benchmarking tools. By comparing the results of performance measurement, it is possible to grasp the success level of project management and to establish the direction of management. However, construction projects are much diversified and even those projects with the same work type have different attributes. Therefore, simply comparing the results of project performance measurement without considering the characteristics of projects is not justifiable and affects the reliability of the benchmarking results. Therefore, to solve this problem, this study presents a methodology that makes it possible to compare the individual construction projects considering various characteristics. The benefits and importance of project characteristics to overall project performance will be quantitatively expressed and they will be reflected on the results of performance management. By maximally converting multiple projects with different characteristics into the same projects through a new methodology to convert different projects into the same level utilizing such utility-bases and comparing the performances of those projects, project performance results can be utilized in project management as a tool for more accurate decision making and as a robust benchmarking tool.

• 대한안전경영과학회지
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• 제18권1호
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• pp.203-208
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• 2016

Bioinformatics service is very new and emerging in market that provides information such as whether or not occurrence of a particular disease through the base of DNA(Deoxyribonucleic Acid) & RNA(Ribo Nucleic Acid) sequence analysis. Recently, interest growing rapidly in utilization of the industrial purpose, but provision of commercialization like pricing and service packaging is not enough to go to market. For go-to-market, firstly refine the services and perform cost calculation of services in cost-plus method then estimate consumer utility by conducting conjoint analysis. Collectively, with cost and consumer utility result, optimal service price can be calculated.

• International Journal of Automotive Technology
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• 제7권6호
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• pp.703-714
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• 2006

The growing concern surrounding rollover incidences and consequences of Sports Utility Vehicles(SUV) have prompted to investigate the sensitivity of critical vehicle parameters on rollover. In this paper, dynamic rollover simulation of Sports Utility Vehicles is carried out using a validated nonlinear vehicle model in Matlab/Simulink. A standard model is considered and critical vehicle parameters like CG height, track width and wheel base are varied within chosen specified limits to study its influence on roll behavior during a Fishhook steering maneuver. A roll stability criterion based on Two Wheel Lift Off(TWLO) phenomenon is adopted for rollover propensity prediction. Further dynamic rollover characteristics of the vehicle are correlated with Static Stability Factor(SSF), Roll Stability Factor(RSF) and Two Wheel Lift Off Velocity(TWLV). These findings will be of immense help to SUV chassis designers to determine safety limits of critical vehicle parameters and minimize rollover incidences.

• Journal of Communications and Networks
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• 제11권5호
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• pp.464-472
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• 2009

In this paper, we propose a packet scheduling algorithm for cellular relay networks by considering relay selection, variation of channel quality, and packet delay. In the networks, mobile users are equipped with not only cellular but also user relaying radio interfaces, where base station exploits adaptive high speed downlink channel. Our proposed algorithm selects a user with good cellular channel condition as a relay station for other users with bad cellular channel condition but can get access to relay link with good quality. This can achieve flexible packet scheduling by adjusting transmission rates of cellular link. Packets are scheduled for transmission depending on scheduling indexes which are calculated based on user's achieved transmission rate, packet utility, and proportional fairness of their throughput. The performance results obtained by using computer simulation show that the proposed scheduling algorithm is able to achieve high network capacity, low packet loss, and good fairness in terms of received throughput of mobile users.

• Clinical and Experimental Pediatrics
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• 제52권11호
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• pp.1249-1259
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• 2009

목 적:소아 성장호르몬결핍증의 저신장 치료에 사용되는 성장호르몬 생물학적 제제인 서방형 주사제의 비용-효과성을 사회적 관점에서 기존 매일 주사제와 비교하여 평가하고자 한다. 방 법:성장 호르몬 치료를 받는 환아를 대상으로 시각화 척도 방법에 의해 건강 관련 효용을 측정하였다. 2008년 7월, 이 연구에 참여한 2개 병원에서 저성장증 치료를 받고 있는 149명의 환아 보호자에게 매일 주사제에 대한 효용과 주 1회 주사제를 사용할 경우 기대되는 효용을 인터넷을 통해 설문조사 하였다. 성장호르몬 주사요법 중 매일 주사제와 주 1회 주사제 투여에 소요되는 직․간접 비용은 차이가 없으므로, 두 제형의 의약품비만을 비교하였다. 결 과:매일 주사제에서 주 1회 주사제로 전환할 경우 예상되는 효용값은 0.584에서 0.784로 증가하며, 연평균 추가비용은 4,060,811원이 발생한다. 점증적 비용-효용비는 20,304,555원/QALY (quality-adjusted life year gained)로 계산되었다. 시나리오 분석 결과, 점증적 비용-효용비는 최소 15,751,198원/QALY에서 최대 25,489,929원/QALY이다. 결 론:Base case 및 시나리오 분석결과에서 제시하는 점증적 비용-효용비는 우리 나라 1인당 GDP의 0.85-1.37배 범위 내에 있으므로 매우 안정적으로 비용-효과성이 있는 것으로 판단된다. 따라서, 매일 주사제에서 주1회 주사제로의 투약방법 변경은 비용-효과적이라 할 수 있으며, 주 1회 주사제가 추가 비용을 부담하더라도 경제성이 우수하다고 결론지을 수 있다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권8호
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• pp.3383-3389
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• 2014

Background: Prostate cancer is rapidly increasing in Korea and professional societies have requested adding prostate specific antigen (PSA) testing to the National Cancer Screening Program (NCSP), but this started a controversy in Korea and neutral evidence on this issue is required more than ever. The purpose of this study was to provide economic evidence to the decision makers of the NCSP. Materials and Methods: A cost-utility analysis was performed on the adoption of PSA screening program among men aged 50-74-years in Korea from the healthcare system perspective. Several data sources were used for the cost-utility analysis, including general health screening data, the Korea Central Cancer Registry, national insurance claims data, and cause of mortality from the National Statistical Office. To solicit the utility index of prostate cancer, a face-to-face interview for typical men aged 40 to 69 was conducted using a Time-Trade Off method. Results: As a result, the increase of effectiveness was estimated to be very low, when adopting PSA screening, and the incremental cost effectiveness ratio (ICER) was analyzed as about 94 million KRW. Sensitivity analyses were performed on the incidence rate, screening rate, cancer stage distribution, utility index, and treatment costs but the results were consistent with the base analysis. Conclusions: Under Korean circumstances with a relatively low incidence rate of prostate cancer, PSA screening is not cost-effective. Therefore, we conclude that adopting national prostate cancer screening would not be beneficial until further evidence is provided in the future.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 추계학술대회 논문집 전력기술부문
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• pp.261-263
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• 2007

In the past, the power expansion planning (PEP) used least cost optimization. But PEP is required considering variable attributes. Because the environment of power industry changes very fast. This paper presents PEP using a multi-attribute decision method (MADM). MADM base on preference and utility.

• 대한교통학회지
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• 제14권4호
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• pp.31-48
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• 1996

This paper develops a disaggregate model system for travel behavior of workers in a metropolitan area. We attempt to develop a set of models for predicting trip generation type, trip purpose, destination, mode choices in each trip on the way from work to home by using the concept of utility maximization of base-to-base tour. The model incorporates the concept that decisions of a trip in a trip in a travel tour depend on decisions of the trips having been made before and decisions of trip planned after of this trip, as well as on current trip conditions. As the structure of the model, the nested logit model is used to avoid a simultaneous model's complexity. The data to be used for estimating the model system are from the person trip survey which was carried out in 1981 in Nagoya metropolitan. Empirical tests of the model for Nagoya metropolitan area show encouraging results and prove the validity of the assumption of this model.