• ETRI Journal
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• 제28권3호
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• pp.371-374
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• 2006

We propose and analyze a priority queuing scheme that gives priority in the same class of calls according to their total resource requirements (TRRs). The proposed scheme gives a higher priority to the calls that have a lower TRR over the calls that have a higher TRR. The numerical results show that the proposed priority queuing scheme provides better performance than the traditional queuing schemes in call blocking probability.

• 한국통신학회논문지
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• 제29권12A호
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• pp.1298-1308
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• 2004

CDMA시스템에서 서로 다른 종류의 호에 서로 다른 우선권을 할당하는 호 수락제어(CAC: Call Admission Control)기법은 많은 연구가 이루어졌다. 본 논문에서는 사용자의 전체 자원요구량에 근거하여 같은 종류의 호에도 서로 다른 우선권을 할당하는 호 수락제어기법을 제안하고 그 성능을 분석한다. 제안하는 알고리즘은 한 기지국에서의 자원요구량이 아닌 전체 시스템에서의 자원요구량에 근거하여 같은 종류의 호에 서로 다른 우선권을 할당한다. 새로운 호의 호 신청수락여부를 결정할 때 시스템에 충분한 여유용량이 있으면 모든 호를 수락하지만 모든 호들을 받아들일 수 없으면 우선권이 높은 호부터 받아들인다. 분석결과는 제안된 알고리즘이 같은 종류의 호에 서로 다른 우선권을 할당하지 않는 알고리즘보다 호 차단확률과 통화품질 저하확률 및 전송부하에서 모두 우수한 성능을 나타냄을 보여준다.

• 산업공학
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• 제11권3호
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• pp.65-75
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• 1998

This research considers the problem of scheduling jobs on parallel machines with non-common due dates and additional resource constraints. The objective is to minimize the total absolute deviation of job completion times about the due dates. Job processing times are assumed to be the same. This problem is motivated by restrictions that occur in the handling and processing of jobs in certain phases of semiconductor manufacturing and other production systems. We examine two problems. For the first of these, the number of different types of additional: resources and resource requirements per job are arbitrary. The problem is formulated as a zero-one integer linear programming and the Lagrangian relaxation approach is used. For the second case, there exists one single type of additional resource and the resource requirements per job are zero or one. We show how to formulate the problem as an assignment problem.

• International Journal of Internet, Broadcasting and Communication
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• 제16권3호
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• pp.16-26
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• 2024

Mobile edge computing (MEC) plays a crucial role in improving the performance of resource-constrained mobile devices by offloading computation-intensive tasks to nearby edge servers. However, existing methods often neglect the critical consideration of future task requirements when making offloading decisions. In this paper, we propose an innovative approach that addresses this limitation. Our method leverages recurrent neural networks (RNNs) to predict task sizes for future time slots. Incorporating this predictive capability enables more informed offloading decisions that account for upcoming computational demands. We employ genetic algorithms (GAs) to fine-tune fitness functions for current and future time slots to optimize offloading decisions. Our objective is twofold: minimizing total processing time and reducing energy consumption. By considering future task requirements, our approach achieves more efficient resource utilization. We validate our method using a real-world dataset from Google-cluster. Experimental results demonstrate that our proposed approach outperforms baseline methods, highlighting its effectiveness in MEC systems.

• 한국산학기술학회논문지
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• 제17권12호
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• pp.708-715
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• 2016

매크로-펨토셀이 중첩된 환경에서 멀티미디어 서비스의 QoE를 보장하는 것은 5G 이동통신을 위한 중요한 문제이다. 이동 단말기가 이동 시 서비스 연속성을 지원하기 위해서는 종단 간 협상 정보에 근거하여 사용자의 QoE를 보장할 수 있는 운영 구조가 필요하다. 또한 멀티미디어 서비스의 연속성은 지연에 영향 받기 때문에 QoE 요구 사항을 효과적으로 유지하기 위한 자원 관리 방법이 필요하다. 본 연구에서는 서로 다른 특성을 갖는 멀티미디어 서비스의 QoE를 지원하기 위하여 4 부류의 자원 관리 방법을 제안한다. 이를 위하여 QoE 구조가 제안되고 QoE를 지원하기 위하여 전용으로 자원을 운용하는 방법을 제안한다. 제안된 방법을 통하여 음성, 영상, 데이터 서비스 등 자원할당 요구 사항이 서로 다른 멀티미디어 서비스의 QoE을 지원할 수 있다. Outage 확률과 데이터 처리율을 성능척도로 하여 수행된 시뮬레이션을 수행하고 결과를 분석한다. Outage 확률과 데이터 처리량을 성능척도로 하여 수행된 시뮬레이션 결과에 의하면 제안된 방안이 기존 방안에 비하여 더 우수한 성능을 가짐이 확인된다.

• 수산해양교육연구
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• 제25권1호
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• pp.139-151
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• 2013

Recently, in the context of increased interest for marine tourism, Jeju region of South Korea has attractive waterfront space and also has potential requirements for development. The objective of this paper was to analyze the priority for resource development of waterfront in Jeju region. In order to calculate the importance of factors related to the development of waterfront in Jeju area, this study conducted exploratory factor analysis to extract the factors and established the AHP model based on the factors name focusing on a total of 198 tourists. In this study, in accordance with the procedures of AHP analysis, pairwise comparisons were conducted focusing on a total of 15 experts. Especially, difference test between groups (academics and bureaucratic) was conducted. In the 1st criterion for evaluation, 'exploring experience' factor is most important thing and 'facilities & infrastructure' factors were in the following order. In the secondary criterion, AHP analysis showed that experience facilities, environmental management, and absence of residents consciousness were the important factors. In the future time, the results of this research can be utilized as basic data in the aspects of tourism development in Jeju waterfront region.

• 자원ㆍ환경경제연구
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• 제15권3호
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• pp.531-553
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• 2006

가정부문 에너지소비의 경우 주로 전력, 난방유, 휘발유, 도시가스, 지역난방 등과 같이 가계가 직접 구입하고 있는 에너지에 대하여 분석이 이루어지고 있다. 총지출 중에서 이러한 직접에너지 구입이 차지하는 비중이 작기 때문에 많은 가계들은 에너지절약에 별 관심을 두지 않고 있다. 2000년의 경우 한국 가정부문은 총지출의 6.2%만을 직접에너지 구입에 사용하였다. 본고는 산업연관표를 사용하여 1990~2000년 기간 동안 한국의 가정부문 직간접 에너지소비를 추정하고, 요인분해방법을 사용하여 가정부문 에너지 총소비 증가요인을 성장효과, 구조효과와 효율효과로 분석하였다. 한국의 가정부문은 2000년에 직접과 간접적으로 각각 1차 에너지의 약 20%와 31%를 소비하였다. 반면에 기존 에너지통계는 자가용 수송에너지를 제외한 2000년 가정부문의 에너지소비를 최종에너지의 15.5%로 추정하고 있다. 간접 에너지를 포함하면 가정부문이 1차 에너지소비의 최대 경제부문이 된다. 가정부문 에너지소비의 60%는 간접 소비다. 에너지 다소비 철강 및 화학 업종을 제외하면 간접에너지 비율이 직접에너지 비율보다 월등히 높다. 따라서 직접 에너지소비보다는 간접과 총 에너지소비가 에너지절약 정책의 주요 대상이 되어야 한다.

• 자원ㆍ환경경제연구
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• 제9권5호
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• pp.811-827
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• 2000

Since improved thermal efficiency reduces capacity requirements and energy costs, electricity producers often treat thermal efficiency as a measure of management or economic performance. The conventional measure of the thermal efficiency of a fossil-fuel generation system is the ratio of total electricity generation to the simple sum of energy inputs. As a refined approach, we present a novel thermal efficiency measure using the concept of the Divisia index number. Application of this approach to the Korean power sector shows improvement of thermal efficiency of 1.1% per year during 1970-1998. This is higher than the 0.9% improvement per year given by the conventional method. The difference is attributable to the effect of fuel substitution. In the Divisia decomposition context, we also show the limitations of the popular $T{\ddot{o}}rnqvist$ index formula and the superiority of the Sato-Vartia formula.

• 농업과학연구
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• 제44권2호
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• pp.254-260
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• 2017

The primary goals of this research were to evaluate the impact of diet supplemented with 25-hydroxyvitamin $D_3$ ($Hy{\cdot}D(R)$) on sow's body condition and reproduction performance. A total of sixteen multiparous sows [(Landrace ${\times}$ Yorkshire), average parity = $3.79{\pm}0.32$] and their litters were randomly allotted to 2 treatments to give 8 replicates per treatment. Diet treatments were randomized to receive a non-active (ND) or active 25-hydroxyvitamin $D_3$ (AD) diet (0.36 mg cholecalciferol/g) during pregnancy. The results of this experiment were observed at the gestation of d 58 - 75, d 76 - 95, d 96 - 110, and d 111 - 115. A corn-soybean meal-based diet was formulated to meet or exceed the nutrient requirements recommended by NRC (2012). Results indicated that the sows' farrowing duration was shortened (4.71, 5.38 h), and the average number of mummified fetuses decreased significantly (p < 0.05) in AD treatment compared with ND treatment (0.1, 0.5) while birth weight was significantly (p < 0.05) improved (1.44, 1.18 kg). There were no significant effects on body weight, backfat thickness, and fecal score during the gestation of sows in different phases (p > 0.05). And the total birth, stillbirth, live birth, and survival rates of the litter did not change (p > 0.05). The results of this study suggest that the farrowing duration of sow pigs will be shortened and the number of mummies will be decreased while their litters' body weight may be improved, if fed active 25-hydroxyvitamin $D_3$ (0.36 mg/g) during pregnancy phase.

• Asian-Australasian Journal of Animal Sciences
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• 제30권10호
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• pp.1435-1441
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• 2017

Objective: The objective of this study was to determine the effect of adding water to total mixed ration (TMR) on fresh water intake, nutrient digestibility, wool cortisol, and blood indices in Corriedale ewes under hot and humid conditions. Methods: Nine non-pregnant Corriedale ewes (ave. body weight = $41{\pm}3.5kg$) were individually fed diets based on maintenance requirements in metabolic crates. Ewes were assigned to three treatment groups according to a triplicate $3{\times}3$ Latin Square design for 3 periods of 21 days duration each (9 ewes per treatment, 27 replications). Treatments were TMR (crude protein [CP] = 16.1, total digestible nutrients = 69.1%) moisture levels for 40%, 50%, and 60%. Results: No differences were found in body weight gain among all treatment groups (p>0.05). Nitrogen balance including digestible N, retained N, and urinary and fecal N showed no change among the treatment groups (p>0.05). Fresh water intake was the lower in 50% TMR moisture group than in the other groups (p<0.05). Other than ether extract which was higher in 60% TMR moisture group (p<0.05) the differences among nutrient digestibilities including CP, organic matter, dry matter, neutral detergent fiber, acid detergent fiber, and non-fiber carbohydrate were not significant (p>0.05). No significant difference was observed for serum protein, blood urea nitrogen, glucose, and triglyceride among the treatment groups (p>0.05). Wool and blood cortisol were not different among the treatment groups (p>0.05). Blood hematology including red blood cell, white blood cells, hemoglobin, hematocrit, basophils, and eosinophils were not different among the treatment groups (p>0.05). Conclusion: It is concluded that TMR moisture at 40%, 50%, and 60% had no effects on N balance parameters, and nutrient digestibilities except for the ether extract under hot and humid conditions. Additionally there were no effects on stress conditions include wool cortisol, as well as blood cortisol levels of ewes.