• 한국산업정보학회논문지
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• 제25권2호
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• pp.39-47
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• 2020

본 논문은 추가 비용 없이 전기자동차(EV) 주행 범위를 확장하기 위해 에너지 효율적인 전기자동차 주행 프로파일을 도출하는 새로운 시스템 수준의 프레임 워크를 소개한다. 이 논문은 먼저 운전 차량에 작용하는 힘과 모터 효율을 고려한 전기차 파워 트레인 모델을 구현한 후, 경로에 의해 정의된 주행 임무에 대한 최소 에너지 주행 프로파일을 도출한다. 이를 위해서 본 프레임워크는 먼저 최적화 문제를 공식화하고, 가중치 계수를 이용한 동적 프로그래밍 알고리즘을 사용하여 에너지 소비와 운전 시간을 모두 최소화하는 주행 프로파일을 도출한다. 본 논문은 주행 시간 제약을 만족시키기 위한 다양한 가중치 계수 도출 방법을 소개한다. 시뮬레이션 결과, 제안 된 스케일링 알고리즘의 연산시간이 이진 검색 알고리즘 및 탐욕 알고리즘보다 각각 34 % 및 50 % 더 작음을 보여준다.

• 대한지역사회영양학회지
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• 제9권3호
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• pp.315-325
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• 2004

This study was conducted to develop the standard breakfast menu for those weak groups having insufficient breakfast intake. The following three target groups are classified as: 16-19 years old high school male student, 20-29 years old female who have job or college students, 20-29 years old male or female who have job (double income family). While developing menus for each target groups, we applied several basic guidelines for meal planning as follows: Nutrient intake level was set to $\graction one-Third$ of RDA, while the energy level to $\fraction one-quarter $ of RDAs. Most Sequent meal pattern of Koreans was adapted; Suitabilities of appropriate serving size and cost for middle-income families were considered; Domestic foods and ingredients were used. We developed 24 menus summed by 2 menus for each season and three target groups. When evaluating the menus, most of the breakfast menus were sufficient of nutrients as a meal for the subjects. Three food groups such as grain/starch group, meat/fish/egg/bean group, vegetable/fruit group were included in all menus. Even though milk/dairy products group was not excluded for some menus, other calcium substitutes like anchovies were used. Oil/nut/sugar group was used to a minimum. The average number of foods for each menu was 12.8, which ranged from 10 to 17 depending on the menus. The average weight of the menus including soup was 822 g, 633 g and 730 g for each target group, respectively. The average price of the menu ranged from 2,000 to 3,500 won per person. The above results could be applied at home as well as foodservice institutes and furthermore could offer information for developing breakfast-substituting food products.

• 한국멀티미디어학회논문지
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• 제9권5호
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• pp.606-614
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• 2006

기존에 이동 Ad Hoc On-demand 방식의 대표적인 DSR과 AODV 프로토콜 라우팅 알고리즘은 단지 경로의 손실이 발생할 경우에만 경로 발견을 시작하며, 단절된 경로를 발견하고 새로운 경로 확립하는데 막대한 경비와 시간이 소요된다. 본 논문에서는 기존의 대표적인 DSR과 AODV 프로토콜 라우팅 알고리즘에서 제안하는 견고한 On-demand 방식의 사전 활성화 경로 선택과 관리유지 알고리즘의 추가시키는 측면을 연구한다. 본 연구의 핵심 아이디어는 수신되는 패킷의 신호파워 세기가 손실되기 전의 최적 임계치 신호파워 세기까지 근접하게 되면 경로는 손실될 경향이 높다고 간주하는 것과 수신되는 패킷의 신호파워 세기가 최적 임계치 이하로 떨어졌을 경우, 사전경고 패킷을 발생하는 것이다. 사전경고 패킷을 발생 후에, 송신 노드는 계속적으로 패킷이 전송하는 동안 사전에 경로 발견을 시작하기 때문에, 모든 경로의 단절에 대한 잠재적인 가능성을 피할 수 있다. 성능평가 결과에 의하면, 제안하는 견고한 On-demand 방식의 사전 활성화 경로 선택과 관리유지 알고리즘은 기존의 DSR과 AODV 프로토콜보다 패킷 전달율과 평균 지연시간 그리고 오버헤드 측면에서 성능이 우수한 경향을 나타낸다.

• Journal of Korean Neurosurgical Society
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• 제56권3호
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• pp.211-217
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• 2014

Objective : In Korea, early vertebroplasty (EVP) or delayed vertebroplasty (DVP, which is performed at least 2 weeks after diagnosis) were performed for the treatment of acute osteoporotic compression fracture (OCF) of the spine. The present study compared the outcomes of two surgical strategies for the treatment of single-level acute OCF in the thoracolumbar junction (T12-L2). Methods : From 2004 to 2010, 23 patients were allocated to the EVP group (EVPG) and 27 patients to the DVP group (DVPG). Overall mean age was $68.3{\pm}7.9$ and minimum follow-up period was 1.0 year. Retrospective study of clinical and radiological results was conducted. Results : No significant differences in baseline characteristics were observed between the two groups. As expected, mean duration from onset to vertebroplasty and mean duration of hospital stay were significantly longer in the DVPG ($17.1{\pm}2.1$ and $17.5{\pm}4.2$) than in the EVPG ($3.8{\pm}3.3$ and $10.8{\pm}5.1$, p=0.001). Final clinical outcome including visual analogue scale (VAS), Oswestry Disability Index, and Odom's criteria did not differ between the two groups. However, immediate improvement of the VAS after vertebroplasty was greater in the EVPG ($5.1{\pm}1.3$) than in the DVPG ($4.0{\pm}1.0$, p=0.002). The proportion of cement leakage was lower in the EVPG (30.4%) than in the DVPG (59.3%, p=0.039). In addition, semiquantitative grade of cement interdigitation was significantly more favorable in the EVPG than in the DVPG (p=0.003). Final vertebral body collapse and segmental kyphosis did not differ significantly between the two groups. Conclusion : Our findings suggest that EVP achieves a better immediate surgical effect with more favorable cost-effectiveness.

• 자원리싸이클링
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• 제29권4호
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• pp.45-50
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• 2020

전기·전자제품 생산업자와 판매업자는 자신이 배포한 장비가 속하는 등급에 해당하는 폐전기·전자제품을 직접 수거하거나 한국전자제품자원순환공제조합에 가입하여 공제조합이 대리할 의무를 이행하도록 할 수 있다. 본 연구에서는 분담금의 요율체계를 검토하고, 파악한 문제점과 이에 대한 개선방안을 제시한다. 첫째, 수집비 및 운반비에 대해 회수유형별 작업을 고려하여 표준작업 및 시간을 설정해야 한다. 둘째, 리사이클링센터의 선별방식에 차이가 있으므로, 이들 방식의 차이와 처리하는 제품군 특성을 반영하여 할당인자에 대한 표준원가를 설정해야 한다. 셋째, 방문수거비 예측모형에서 최소값이 아닌 중앙값 또는 평균값으로 결정하여 충분한 규모의 예산을 확보해야 한다. 본 연구는 공제회원이 공제조합에 납부하는 분담금의 문제점을 살펴보고 이에 대한 개선방안을 제시하였다.

• 대한원격탐사학회지
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• 제21권2호
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• pp.163-171
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• 2005

합성구경레이더(Synthetic Aperture Radar) 원시 자료(raw data)를 range-Doppler 알고리듬을 이용하여 처리하는 교육용 공개 프로그램을 개발하였다 이 프로그램은 SAR 시스템에 따라 자료처리에 필요한 변수를 자유롭게 조절함으로써, 특정 SAR 시스템에 치우치지 않고 다양한 자료를 처리할 수 있도록 일반화된 알고리듬을 구현하였다. 저가 사양의 컴퓨터에서도 최소 단위의 영상을 선택적으로 처리할 수 있고 자료 처리 중간 단계별로 영상 출력이 가능하기 때문에, 프로그램 작동 상태와 SAR의 원리를 직접 확인할 수 있도록 하였다. 특히 Doppler 변수를 자료 처리 중간 단계의 영상을 보고 직접 구할 수 있도록 고안하여 교육적 효과를 높였다. 또한 자료 처리 알고리듬과 원시프로그램을 모두 공개함으로써, SAR 시스템 원리를 이해하고 응용하는데 도움을 주고자 한다. 이 논문에서는 프로그램의 원리와 작동 환경을 소개하고, ERS-1 원시 자료를 이용한 자료 처리의 예를 보였다.

• 한국유기농업학회지
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• 제27권1호
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• pp.1-16
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• 2019

The questionnaire survey was conducted on 225 farmers in Gyeonggi-do, Jeollanam-do and Jeollabuk-do. A total of 189 (84%) farmers responded. 72% of the respondents were males, 50.3% were aged 60 or older, and 51.3% had less than 5 years of farming experience. 78.8% of the respondents are pesticide-free, and 44.4% of respondents have less than 0.5 ha of farming scale. 61.4% of the cultivated crops were vegetable crops. The order of seeds and seedlings to buy was tomato (23.3%), cucumber (12.2%) and pepper (10.6%). The cost of purchasing seeds ranged from a minimum of 100,000 won to a maximum of 5 million won. 78.3% of respondents answered that they well-knew or knew about organic seeds. 78.3% of respondents answered that they knew or knew about organic seeds. Of the positive effects of mandatory use of organic seeds, 41.3% of respondents said they would increase confidence in organic certification. However, 41% of respondents who opposed the mandatory use of organic seeds said that "The strengthening of regulations will make organic agriculture more difficult." When the use of organic seeds is mandatory, 43.4% of the respondents favor direct support for the purchase of organic seeds, which should be supported politically by the state. When organic seeds were supplied, the disease resistant seeds (53.4%) was the preferred characteristic of organic seeds. For the optimal price of organic seeds, 38.6% of respondents wanted the same price as the commercialized conventional seed. In this study, the questionnaire was conducted for three major organic farming regions, but many of the respondents were judged to have a legal position on the mandatory use of organic seeds. Therefore, the results of this study can be used as a basic data for reviewing the legislation on the organic seed production and distribution suitable for the situation of Korean organic farming.

• 해양환경안전학회지
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• 제23권7호
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• pp.965-971
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• 2017

본 논문의 주 목적은 기존선형과 저항을 최소화하는 최적선형에 대한 에너지효율 성능을 평가하는 것이다. 설계 흘수와 설계 선속을 고려하여 대상선박의 선수부 형상을 검토하였다. 실제 운항 상태에서 대상선박의 저항성능을 평가하였다. 상용 전산유체역학(CFD) 코드와 수조 모형시험 자료는 유효마력 평가를 위해 사용되었다. 실제 운항 상태를 고려하여 최소저항을 가지는 최적선형을 제시하였다. 기존선형과 최적선형에 대하여 3가지 선속에서 유효마력을 추정하였다. 최적선형의 저항성능은 기존선형과 비교하여 볼 때 설계속도(12노트)에서 약 6 % 향상된 결과를 보여 주었다. 준추진효율 계수(ETAD, ${\eta}_D$)는 모형시험 자료를 활용하였다. 에너지 효율 성능은 년간 운항일수, 벙커C유 가격, 1일 연료사용량 그리고 연료소비계수를 바탕으로 작성되었다. 최적선형의 에너지 효율 성능은 기존선형과 비교하였을 때 12노트에서 연간 약 3천만원 절약된 결과를 보여 주었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권12호
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• pp.5701-5722
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• 2018

The continuous increase in the cost of energy production and concerns for environmental sustainability are leading research communities, governments and industries to amass efforts to reduce energy consumption and global $CO_2$ footprint. Players in the information and communication industry are keen on reducing the operational expenditures (OpEx) and maintaining the profitability of cellular networks. Meanwhile, network virtualization has been proposed in this regard as the main enabler for 5G mobile cellular networks. In this paper, we propose a generic framework of slice resource provisioning and customized physical resource allocation for energy-efficiency and quality of service optimization. In resource slicing, we consider user demand and population resources provisioning scheme aiming to satisfy quality of service (QoS). In customized physical resource allocation, we formulate this problem with an integer non-linear programming model, which is solved by a heuristic algorithm based on minimum vertex coverage. The proposed algorithm is compared with the existing approaches, without consideration of slice resource constraints via system-level simulations. From the perspective of infrastructure providers, traffic is scheduled over a limited number of active small-cell base stations (sc-BSs) that significantly reduce the system energy consumption and improve the system's spectral efficiency. From the perspective of virtual network operators and mobile users, the proposed approach can guarantee QoS for mobile users and improve user satisfaction.

• 한국산업융합학회 논문집
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• 제25권2_2호
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• pp.209-218
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• 2022

The purpose of this study is to analyze an economic assessment of PV-ESS systems based on the power generation performance data of solar power (PV) operating in domestic area, and to calculate the optimal capacity of the energy storage system. In this study, PVs in Gyeonggi-do, Jeollabuk-do, and Gyeongsangbuk-do were targeted, and PVs in this area were assumed to be installed on a general site, and the research was conducted by applying weights based on the facility's capacity. All the analysis was conducted using the actual amount of KPX transactions of PVs in 2019. In order to calculate the optimal capacity of PCS and BESS according to GHI, PV with a minimum/maximum/central value was selected by comparing the solar radiation before the horizontal plane between three years (2017-2019) of the location where PV was installed. As a result of the analysis, in Gyeonggi-do, if the REC weight decreases to 3.4 when there is no change in the cost of installing BESS and PCS, it is more economical to link BESS than PV alone operation of PV. In Jeollabuk-do, it was analyzed that if the REC weight was reduced to 3.6, it was more likely to link BESS than PV operated alone. In Gyeongsangbuk-do, it was analyzed that if the REC weight was reduced to 3.4, it was more likely to link BESS than PV operated alone.