• 대한산업공학회지
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• 제36권4호
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• pp.219-229
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• 2010

The PERT/CPM are considered as the base procedures for the most successful project scheduling programs. Unfortunately, it is not easy to apply these procedures to real-life projects. This is due to the fact that PERT/CPM assume an infinite number of resources for each activity in project networks. Obviously, the completion time under no constraints is less than when constraints are imposed. One way of approaching this problem is to use heuristic solution techniques. In this paper, we present three heuristics; MRU (Maximum Resource Use) rule, STU (Shortest Time Use) rule, MRUP (Max Resource Use and Period) rule for allocating resources to activities of projects under multiple resource constraints. Comparisons of the project durations show that these heuristic rules are superior to AG3 rule that has been widely used in practice (Elsayed and Boucher, 1994).

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권7호
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• pp.2350-2364
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• 2014

This paper addresses the problem of resource allocation in amplify-and-forward (AF) relayed OFDM based cognitive radio networks (CRNs). The purpose of resource allocation is to maximize the overall throughput, while satisfying the constraints on the individual power and the interference induced to the primary users (PUs). Additionally, different from the conventional resource allocation problem, the rate-guarantee constraints of the subcarriers are considered. We formulate the problem as a mixed integer programming task and adopt the dual decomposition technique to obtain an asymptotically optimal power allocation, subcarrier pairing and relay selection. Moreover, we further design a suboptimal algorithm that sacrifices little on performance but could significantly reduce computational complexity. Numerical simulation results confirm the optimality of the proposed algorithms and demonstrate the impact of the different constraints.

• Industrial Engineering and Management Systems
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• 제10권1호
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• pp.54-64
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• 2011

The purpose of this study is to optimally allocate the human resources to tasks while minimizing the total daily human resource costs and smoothing the human resource usage. The human resource allocation problem (hRAP) under consideration contains two kinds of special constraints, i.e. operational precedence and skill constraints in addition to the ordinary constraints. To deal with the multiple objectives and the special constraints, first we designed this hRAP as a network problem and then proposed a Pareto multistage decisionbased genetic algorithm (P-mdGA). During the evolutionary process of P-mdGA, a Pareto evaluation procedure called generalized Pareto-based scale-independent fitness function approach is used to evaluate the solutions. Additionally, in order to improve the performance of P-mdGA, we use fuzzy logic controller for fine-tuning of genetic parameters. Finally, in order to demonstrate the applicability and to evaluate the performance of the proposed approach, P-mdGA is applied to solve a case study in a hotel, where the managers usually need helpful automatic support for effectively allocating hotel staff to hotel tasks.

• 산업공학
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• 제13권1호
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• pp.110-119
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• 2000

Resource-constrained project scheduling is to allocate limited resources to activities to optimize certain objective functions and to determine a start time for each activity in the project such that precedence constraints and resource requirements are satisfied. This study suggests a multi-project scheduling model which can level work loads, make the most of production capacity and restrain the delay of delivery by developing a heuristic algorithm which minimizes the project completion time and maximizes the load rate under resource constraints.

• 한국컴퓨터정보학회논문지
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• 제23권4호
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• pp.107-114
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• 2018

Recently, various wearable personal devices such as a smart watch have been developed and these personal devices are being miniaturized. The user desires to receive new services from personal devices as well as services that have been received from personal computers, anytime and anywhere. However, miniaturization of devices involves constraints on resources such as limited input and output and insufficient power. In order to solve these resource constraints, this paper proposes a resource collaboration system which provides a service by composing sharable resources in the resource sharing environment like IoT. the paper also propose a method to infer and recommend user-customized resources among various sharable resources. For this purpose, the paper defines an ontology for resource inference. This paper also classifies users behavior types based on a user model and then uses them for resource recommendation. The paper implements the proposed method as a prototype system on a personal device with limited resources developed for resource collaboration and shows the effectiveness of the proposed method by evaluating user satisfaction.

• 가족자원경영과 정책
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• 제17권1호
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• pp.241-263
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• 2013

Time pressure and financial burden have been reported as the main constraints on leisure participation. The purpose of this study was to explore a typology of leisure constraints, investigate the characteristics of leisure constraint types, and analyze the differences in leisure participation by the types of leisure constraints for married employees. The data source for this research was the 2009 Time Use Survey conducted by the Korea National Statistical Office (KNSO). Married employees aged 20 to 59 years completed 13,476 time diaries (7,984 for male, 5,492 for female), which were analyzed using chi-square, cluster analysis, and ANOVA analysis. Leisure constraints were classified into five types in two categories, working time per week and personal income for both males and females respectively. The three types for both males and females were time-income constraints, income constraints, and general constraints, with an additional type for men, $time^+$-income constraints, and an additional type for women, time constraint. The most common type was general constraints, for both males and females. Each type was further differentiated by the following socio-economic variables: age, educational level, job type, and weekly day-off. The study found that participation in study, sports, and religious activities varied with the types of leisure constraints.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권5호
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• pp.1569-1586
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• 2015

This paper considers the optimal cell association and resource allocation for load balancing in a heterogeneous cellular network subject to user's quality-of-service (QoS) constraints. We adopt the proportional fairness (PF) utility maximization formulation which also accommodates the QoS constraints in terms of minimum rate requirements. With equal resource allocation this joint optimization problem is either infeasible or requires relaxation that yields a solution which is difficult to implement. Nevertheless, we show that this joint optimization problem can be effectively solved without any priori assumption on resource allocation and yields a cell association scheme which enforces single BS association for each user. We re-formulated the joint optimization problem as a network-wide resource allocation problem with cardinality constraints. A reweighted heuristic l₁-norm regularization method is used to obtain a sparse solution to the re-formulated problem. The cell association scheme is then derived from the sparsity pattern of the solution, which guarantees a single BS association for each user. Compared with the previously proposed method based on equal resource allocation, the proposed framework results in a feasible cell association scheme and yields a robust solution on resource allocation that satisfies the QoS constraints. Our simulations illustrate the impact of user's minimum rate requirements on cell association and demonstrate that the proposed approach achieves load balancing and enforces single BS association for users.

• 산경연구논집
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• 제5권2호
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• pp.29-35
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• 2014

Purpose - The study aimed to evaluate the market opportunities and constraints confronting resource-poor pig farmers in South Africa. Research design, data, and methodology - Information was collected from 292 households in three municipalities through interviews with key informants. The data collected included socio-economic characteristics, major market channels, prices for different pig classes, average weight of the pigs on sale, number of pigs sold annually, and preferred meat quality attributes. Results - In Ngqushwa, 96% of respondents sold pigs as compared to Elundini (81%) and Ntabankulu (65%). Less resource-poor households and those with market-oriented production had large herdsizes (P < 0.05) when compared to more resource-poor farmers. The probability of selling pigs was high for the backyard production system and educated farmers. For all farmers, opportunities included high pork demand, good prices, employment creation, and a niche market for organically produced indigenous pork. Constraints include disease, feed shortages for large herds, distances to formal markets, lack of training, and drugs. Conclusions - Constraints outnumbered opportunities for the resource-poor pig farmers.

• 규제연구
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• 제27권2호
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• pp.71-104
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• 2018

자원제약에 대한 규제기관의 대응행태는 규제의 효과성 측면에서 중요한 이슈임에도 불구하고 체계적인 연구가 부족하다. 본 연구는 이러한 한계를 벗어나기 위한 노력으로서 규제자원이 제약된 상황에 대응한 규제기관의 행태를 시론적으로 제시하는 데에 주된 목적을 두었다. 구체적으로, 규제이론과 조직이론에 기반한 선행연구를 비판적으로 검토하여 자원이 부족한 상태에서 나타날 가능성이 있는 규제기관의 행태(규제과정상의 변화, 집행방식의 변화, 비동조화, 규제위임과 민간위탁)를 제시하였다. 이 과정에서 주로 해운규제분야 사례들을 통해, 도출한 대응행태의 현실적인 설명가능성을 살펴보았으며, 자원제약에 대응한 규제기관의 행태가 가져올 수 있는 문제점에 대해서도 논의하였다. 연구결과를 토대로 규제자원의 부족 상태에서 규제기관이 보일 행태를 고려하여 규제의 효과성을 보다 담보할 수 있는 규제체계를 설계할 필요가 있다는 시사점을 제시하였다. 본 연구는 향후 실제 자원제약을 받고 있는 우리나라 규제기관들의 행태를 실증적으로 분석할 수 있는 이론적 분석틀을 마련하는 데에 도움을 주리라 기대한다.

• 가정과삶의질연구
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• 제24권1호
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• pp.11-30
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• 2006

The purpose of this study was to verify a Structural Equation Model that constructed the causations among the leisure constraints, leisure. motivation, and leisure participation. This model posits that constraints determine motivation to participation. Concretely, structural and interpersonal leisure constraints(contextual factors) will affect interpersonal leisure constraints in the light of ecological perspective. Also, leisure constraints will affect leisure motivation based on self-determination theory that may influence leisure participation indirectly. A survey questionnaire was administered to 301 elderly in an institution for the elderly. A measurement model and a structural equation model estimates by Maximum Likelihood method(ML method) utilizing LISREL 8.0 ver. The analysis showed that a goodness of fit is good of structural equation model presented in the study. And, all hypothesis adopted about causations among the leisure constraints, leisure motivation, leisure participation.