• Proceedings of the Korean Operations and Management Science Society Conference
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• 1994.04a
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• pp.561-568
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• 1994

A man model can be used as an effective tool to design ergonomically sound products and workplaces, and subsequently evaluate them properly. For a man model to be truly useful, it must be integrated with a posture prediction model which should be capable of representing the human arm reach posture in the context of equipments and workspaces. Since the human movement possesses redundant degrees of freedom, accurate representation or prediction of human movement was known to be a difficult problem. To solve this redundancy problem, a psychophysical cost function was suggested in this study which defines a cost value for each joint movement angle. The psychophysical cost function developed integrates the psychophysical discomfort of joints and the joint range availability concept which has been used for redundant arm manipulation in robotics to predict the arm reach posture. To properly predict an arm reach posture, an arm reach posture prediction model was then developed in which a posture configuration that provides the minimum total cost is chosen. The predictivity of the psychophysical cost function was compared with that of the biomechanical cost function which is based on the minimization of joint torque. Here, the human body is regarded as a two-dimensional multi-link system which consists of four links ; trunk, upper arm, lower arm and hand. Real reach postures were photographed from the subjects and were compared to the postures predicted by the model. Results showed that the postures predicted by the psychophysical cost function closely simulated human reach postures and the predictivity was more accurate than that by the biomechanical cost function.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.4
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• pp.389-394
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• 2010

This paper describes the conceptual design of mass memory unit for high speed data processing and mass memory management in the STSAT-3 compared to that of STSAT-2. The FPGA directly controls the data receiving from two payloads with the maximum 100Mbps speed and 32Gb mass memory management to satisfy these requirements. We used SRAM-based FPGA from XILINX having fast operating speed and large logic cells. Therefore, the Triple Modular Redundancy(TMR) and configuration memory scrubbing techniques will also be used to protect FPGA from Single Event Upset(SEU) in space.

• Korean Journal of Construction Engineering and Management
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• v.2 no.4 s.8
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• pp.48-61
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• 2001

This study aims at improving work reliability. It proposes a way to overcome the limitations of current scheduling methods by providing a new framework, CPAM(Construction Process Analysis Model) based on the lean principles. It suggests methods which improve work reliability and production effectiveness with variability control methods. Also it suggests methods which reduce inventories of materials and equipment and WIP(Work In Process) using two techniques; Lookahead Schedule and Weekly Work Plan. The contribution of this research also includes that it assumes planning as a process of reducing uncertainty and maximizing throughput, counter-posing plan reliability to resource redundancy as alternative strategies for managing in conditions of uncertain work flow.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.1702-1706
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• 2006

In the field of rice research, insertional mutants have become a valuable resource for studies of gene function. However, a well-designed database yet in the area of rice functional genomics. The relevant data are widely distributed and independently managed by the individual research groups. Heterogeneous data format in the distributed database systems causes many problems related to redundancy and compatibility. In this research, integration of the distributed databases using agent technology is pursued. In particular, a data integration agent, an ontology agent, a comparison agent, and resource agents are designed, whereby the integrated database is maintained. Moreover a framework for the web-based information system, which provides information to biologists and permits biologists to add new data to the database, is proposed. To establish an interoperable data format, an XML-based data model is also developed adopting ontology concept.

• Journal of the Korean Society for information Management
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• v.21 no.3
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• pp.289-303
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• 2004

This experimental study proposes a multi-document summarization method that produces optimal summaries in which users can find answers to their queries. In order to identify the most effective method for this purpose, the performance of the three summarization methods were compared. The investigated methods are sentence clustering, passage extraction through spreading activation, and clustering-passage extraction hybrid methods. The effectiveness of each summarizing method was evaluated by two criteria used to measure the accuracy and the redundancy of a summary. The passage extraction method using the sequential bnb search algorithm proved to be most effective in summarizing multiple documents with regard to summarization precision. This study proposes the passage extraction method as the optimal multi-document summarization method.

• Journal of Korea Society of Digital Industry and Information Management
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• v.7 no.4
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• pp.15-22
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• 2011

U-Healthcare service is a real-time service using the vital signs which are continuously transferred from monitoring sensors attached to mobile patients under the wireless network environments. It should monitor the health condition of mobile patients everywhere at any time. In this paper, we have improved two features of the three layered mobile patient monitoring system with load balancing ability. First, the simulation process has been improved by allowing the number of related nodes to be changed. Secondly, we have modified S node to which queue is added to reduce the loss rate of collecting data from patients during the delay of S node process. And the data from the patient with high priority can be transferred to the server immediately through the filtering function. Furthermore, we have solved the problem of redundancy in sharing information among S nodes by differentiating process time to each S node. By performing a DEVS Java-based system simulation, we have verified the efficiency of this improved system.

• Journal of the Korean Society of Safety
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• v.38 no.2
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• pp.8-14
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• 2023

In various industrial sites, piping systems play an essential role in stable fluid supply and pressure maintenance. However, these systems are constantly exposed to risks of earthquakes, explosions, fires, and leaks, which can result in casualties or serious economic losses. With rapid advancements in the industry, different-sized piping systems have been launched; however, there are not enough maintenance personnel for troubleshooting and responding to situations where damages occur to piping systems. This increases the need for introducing autonomous damage management systems. In this study, a lab-based piping system was designed and manufactured by referring to the piping system of a naval ship to analyze the effectiveness of autonomous damage management systems. By using this testbed, a representative algorithm, the hydraulic resistance control algorithm, was realized and examinedIn addition, the difference between the averaged pressure and normalized pressure was introduced to improve the performance of the existing algorithm, which faces some limitations with regard to sensor noise and back pressure from the rupture-simulated pipeline part.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.7B
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• pp.745-759
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• 2011

In this paper, we propose the global handover mechanism that is able to provide the unlimited range of next-generation multimedia mobile services in an integrated environment. This mechanism consists of a multicast source based forwarding scheme and a global session management scheme. Global session management scheme provides LMA session information management, global mobility and route optimization. Multicast source based forwarding scheme delivers data between previously attached LMA and newly attached LMA without packet loss. In addition, this scheme removes the redundancy of buffered data. We present a performance evaluation and features analysis by the simulations using the ns-2. Global session management scheme has a less handover latency, propagation delay and signaling cost than the conventional methods. Multicast source based forwarding scheme can deliver buffer data without loss and it has less buffer size than conventional method.

• Journal of Preventive Medicine and Public Health
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• v.50 no.1
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• pp.38-59
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• 2017

Objectives: Few attempts have been made to develop a generic health-related quality of life (HRQoL) instrument and to examine its validity and reliability in Korea. We aimed to do this in our present study. Methods: After a literature review of existing generic HRQoL instruments, a focus group discussion, in-depth interviews, and expert consultations, we selected 30 tentative items for a new HRQoL measure. These items were evaluated by assessing their ceiling effects, difficulty, and redundancy in the first survey. To validate the HRQoL instrument that was developed, known-groups validity and convergent/discriminant validity were evaluated and its test-retest reliability was examined in the second survey. Results: Of the 30 items originally assessed for the HRQoL instrument, four were excluded due to high ceiling effects and six were removed due to redundancy. We ultimately developed a HRQoL instrument with a reduced number of 20 items, known as the Health-related Quality of Life Instrument with 20 items (HINT-20), incorporating physical, mental, social, and positive health dimensions. The results of the HINT-20 for known-groups validity were poorer in women, the elderly, and those with a low income. For convergent/discriminant validity, the correlation coefficients of items (except vitality) in the physical health dimension with the physical component summary of the Short Form 36 version 2 (SF-36v2) were generally higher than the correlations of those items with the mental component summary of the SF-36v2, and vice versa. Regarding test-retest reliability, the intraclass correlation coefficient of the total HINT-20 score was 0.813 (p<0.001). Conclusions: A novel generic HRQoL instrument, the HINT-20, was developed for the Korean general population and showed acceptable validity and reliability.

• Industrial Engineering and Management Systems
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• v.11 no.3
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• pp.233-240
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• 2012

The implementation of business process management (BPM) systems in large number of business organizations transforms BPM system into such a level of maturity and tends to collect large repositories of business process (BP) models. This issue encourages BP flexibility that leads to a large number of process variants derived from the same model, but differing in structure, to be stored in the large repositories of BP models. Therefore, the repositories may include thousands of activities and related business objects with variation of requirements and quality of service. It is a common practice to customize processes from reference processes or templates in order to reduce the time and effort required to design and deploy processes on all levels. In order to address redundancy and underutilization problems, a generic process model, called as reference BP, is absolutely necessary to cover the best of process variants. This study aims to develop multiple-objective business process genetic algorithm (MOBPGA) to find a set of non-dominated (Pareto) solutions of business reference model to enhance conventional approach which considered only a single objective on creating BP reference model by using proximity score measurement. A mixed-integer linear program is constructed to evaluate performance of the proposed MOBPGA on small-scale problems by using standard measures for multiple-objective techniques. The results will show the viability of applying MOBPGA in terms of simultaneously maximizing proximity score measurement, minimizing total duration, and total costs of the selected reference model.