• The Journal of Information Systems
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• v.21 no.2
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• pp.73-96
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• 2012

With emergence of smart technologies(e.g., smartphones), Location-Based Services(LBS) are expected to provide more enhanced values utilizing consumers' personal information than other smart services. However, in contrast to existing smartphone applications, LBS could raised severe consumer's privacy concerns because of rapidly changing information sensitive to consumers. In this context, the purpose of this study is to explore relationships among privacy concerns reduction, trust and intention to use LBS by examining the effect of precedence factors(social presence, reputation, mobile literacy, ability of information control) of privacy concern reduction. In addition, the study investigates the role of personal innovation as a moderating effect between privacy concern reduction and intention to use LBS. The results showed that the proposed precedence factors of privacy concerns with a exception of Mobile Literacy had a positive impact on privacy concerns reduction that then positively affected trust and intention to use LBS. In addition, the relationship between trust and intention to use LBS was significantly supported. Finally, personal innovation as a moderating effect significantly influenced the relationship between privacy concern reduction and intention to use LBS. This study is expected to be a reference for a subsequent study about the spread of LBS application of smartphone. Also, the finding of this study is meaningful for helping service direction to firms providing LBS.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.187-190
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• 2003

Many manufacturing companies consider the integrated and concurrent scheduling because they need the global optimization technology that could manufacture various products more responsive to customer needs. In this paper, we propose an advanced scheduling model to generate the schedules considering resource constraints and precedence constraints in make-to-order (MTO) manufacturing environments. Precedence of work- in-process(WIP) and resources constraints have recently emerged as one of the main constraints in advanced scheduling problems. The advanced scheduling problems is formulated as a multiobjective mathematical model for generating operation schedules which are obeyed resources constraints, alternative workstations of operations and the precedence constraints of WIP in MTO manufacturing. For effectively solving the advanced scheduling problem, the multi-objective hybrid genetic algorithm (m-hGA) is proposed in this paper. The m-hGA is to minimize the makespan, total flow time of order, and maximum tardiness for each order, simultaneously. The m-hGA approach with local search-based mutation through swap mutation is developed to solve the advanced scheduling problem. Numerical example is tested and presented for advanced scheduling problems with various orders to describe the performance of the proposed m-hGA.

• Journal of the Korea Society of Computer and Information
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• v.23 no.3
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• pp.85-92
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• 2018

We consider a project scheduling problem in which the jobs can be compressed by using additional resource to meet the corresponding due dates, referred to as a time-cost tradeoff problem. The project consists of two independent subprojects of which precedence graph is a chain. The due dates of jobs constituting the project can be interpreted as the multiple assessments in the life of project. The penalty cost occurs from the tardiness of the job, while it may be avoided through the compression of some jobs which requires an additional cost. The objective is to find the amount of compression that minimizes the total tardy penalty and compression costs. Firstly, we show that the problem can be decomposed into several subproblems whose number is bounded by the polynomial function in n, where n is the total number of jobs. Then, we prove that the problem can be solved in polynomial time by developing the efficient approach to obtain an optimal schedule for each subproblem.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.38 no.11
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• pp.1-8
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• 2001

Adaptive and Strict Packet Dropping mechanism we proposed in this paper drops adaptively packets for the congestion control, as predicting traffic pattern between each cycle. Therefore the proposed mechanism makes up for the drawback of RIO mechanism and minimizes the wastes of the bandwidth being capable of predicting in Dynamic and Strict Packet Dropping (DSPD) mechanism. And we executed a simulation and analyzed the throughput and packet drop rate based on the Sending Drop Precedence changing dynamically depending on the network traffic and compared RIO and the DSPD. The results show that the proposed mechanism provides better performance on drop precedence levels and stricter drop precedence policy for AF class than RIO and the DSPD mechanism.

• Journal of Intelligence and Information Systems
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• v.17 no.2
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• pp.1-22
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• 2011

In this paper, we propose an adaptive genetic algorithm (aGA) approach for effectively solving the sequencing problem with precedence constraints (SPPC). For effective representation of the SPPC in the aGA approach, a new representation procedure, called the topological sort-based representation procedure, is used. The proposed aGA approach has an adaptive scheme using a fuzzy logic controller and adaptively regulates the rate of the crossover operator during the genetic search process. Experimental results using various types of the SPPC show that the proposed aGA approach outperforms conventional competing approaches. Finally the proposed aGA approach can be a good alternative for locating optimal solutions or sequences for various types of the SPPC.

• Architectural research
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• v.4 no.1
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• pp.53-61
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• 2002

The typical Critical Path Method (CPM) leaves it to the construction managers to overcome two problems in developing networks. First, the construction manager needs to prepare information on the type of activities and their precedence relations in order to develop a network schedule. Second, he or she can include space information into the network schedule such as the locations where the activities take place, only with difficulty. These two problems make it difficult for an inexperienced person to create a network. The purpose of this paper is to provide construction managers with set equations of creating a network schedule for multiunit projects. A space-resource combined network creation are presented in this paper, which includes equations for generating a list of required activities, their precedence relations, and information on their location. Information on the space (location) and the resource is the required data for this method. Based on this information, this method divides a project into a number of activities so that each activity contains the information on the location where the activity takes place and the principal resource required for that activity. Precedence relations are then obtained from the sequence of space and resource. This method has the potential to reduce human efforts in scheduling activities.

• Management Science and Financial Engineering
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• v.22 no.1
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• pp.5-12
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• 2016

We consider a time-cost tradeoff problem with multiple milestones under a chain precedence graph. In the problem, some penalty occurs unless a milestone is completed before its appointed date. This can be avoided through compressing the processing time of the jobs with additional costs. We describe the compression cost as the convex or the concave function. The objective is to minimize the sum of the total penalty cost and the total compression cost. It has been known that the problems with the concave and the convex cost functions for the compression are NP-hard and polynomially solvable, respectively. Thus, we consider the special cases such that the cost functions or maximal compression amounts of each job are identical. When the cost functions are convex, we show that the problem with the identical costs functions can be solved in strongly polynomial time. When the cost functions are concave, we show that the problem remains NP-hard even if the cost functions are identical, and develop the strongly polynomial approach for the case with the identical maximal compression amounts.

• Journal of the Ergonomics Society of Korea
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• v.30 no.1
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• pp.9-17
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• 2011

Consumer products are produced on the premise that consumers can use their products safely and effectively no matter how serious human errors they may make. However, different careers and educational experiences of them may induce diverse human errors when they want to use them. In that sense, not a few policies to reduce human errors may show some implications for human error prevention and industrial design of consumer products. In this paper, producers' safety efforts required by Product Liability(PL) Act were reviewed in view of human error prevention, and legal aspects of manufacturers' responsibility for consumer products were discussed in relation to Product Liability Act. Then, principal approaches for them were introduced under the title of System Safety Precedence. After that, major key points for preventing human errors related with consumer products - such as ergonomic design and effective labeling - were discussed with reference to ISO standards. Therefore, it was shown that all the efforts required by PL Act would be correspondent to human error prevention in the whole manufacturing processes if understood by ergonomists. To make a conclusion, it could be said that, for human error prevention, the principle of System Safety Precedence would be indispensable, and that all the efforts for preventing human errors should be systematically organized in Product Safety Management Systems.

• The Journal of Information Systems
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• v.25 no.1
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• pp.159-182
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• 2016

Purpose This paper aims to develop a novel tabu search algorithm for solving the sequencing problems with precedence constraints. Due to constraints, the traditional meta heuristic methods can generate infeasible solutions during search procedure, which must be carefully dealt with. On the contrary, the candidate order based tabu search (COTS) is based on a novel neighborhood structure that guarantees the feasibility of solutions, and can dealt with a wide range of sequencing problems in flexible manner. Design/methodology/approach Candidate order scheme is a strategy for constructing a feasible sequence by iteratively appending an item at a time, and it has been successfully applied to genetic algorithm. The primary benefit of the candidate order scheme is that it can effectively deal with the additional constraints of sequencing problems and always generates the feasible solutions. In this paper, the candidate order scheme is used to design the neighborhood structure, tabu list and diversification operation of tabu search. Findings The COTS has been applied to the single machine job sequencing problems, and we can see that COTS can find the good solutions whether additional constraints exist or not. Especially, the experiment results reveal that the COTS is a promising approach for solving the sequencing problems with precedence constraints. In addition, the operations of COTS are intuitive and easy to understand, and it is expected that this paper will provide useful insights into the sequencing problems to the practitioners.

• Korean Security Journal
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• no.55
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• pp.31-55
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• 2018

The purpose of this study is to analyze the precedence analysis of traffic safety facilities installation for traffic accidents. The main results were as follows. First, the precedence of the number of traffic safety signs installation for the number of traffic accident is follows. The number of traffic safety signs[total number] (time precedent 1), the number of traffic safety signs[attention] (time precedent 7), the number of traffic safety signs[regulation] (time precedent 7), the number of traffic safety signs[indication] (time precedent 4) precede the number of traffic accidents as negative(-) relationship. Second, the number of traffic signal equipments[pedestrian lamp] (time precedent 2) precedes the number of traffic accidents as negative(-) relationship. Third, the precedence of the increase/decrease rate of traffic safety facilities installation for the increase/decrease rate of traffic accident is follows. The increase/decrease rate of traffic safety signs[total number] (time precedent 1), the increase/decrease rate of traffic safety signs[attention] (time precedent 1), the increase/decrease rate of traffic safety signs[indication] (time precedent 1), the increase/decrease rate of traffic safety signs[auxiliary] (time precedent 1) precede the increase/decrease rate of traffic accidents as negative(-) relationship. Fourth, the increase/decrease rate of traffic signal equipments[pedestrian lamp] (time precedent 0) accompanies the increase/decrease rate of traffic accidents as positive (+) relationship.