• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.177-182
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• 2003

This study is directed toward determining the number and characteristics of psychologically meaningful perceptual dimensions required for assessing the sound Ouaiity with respect to vehicle interior and/or exterior noises. and toward identifying the acoustical or psychoacoustical bases underlying the perception. By nonmetric MDS and clustring analysis of sound quality data sets on our own, of critical importance are two perceptual dimensions for which subjective verdicts can be interpreted as loudness and sharpness. The perceptual dimensions based upon similarity judgments could be accounted for 48% and 24% of the variance. each of which might be a match for the acoustic parameter "A-weighted maximum pressure level"(r= .85) and for the psychoacoustic parameter "sharpness" (r= .65), respectively. On the other hand, the perceptual dimensions based upon preference ratings could explain 66% and 10% of the variance. where the acoustic parameter "A-weighted maximum pressure leve"(r= .92) might be taken to be a best predictor, but sharpness appeared to be less suitable for the description of Preference behavior. Linked to the results, the problems of quantitative modelling of subjective sound quality evaluation and also of implementing corresponding cognitive combination rule for technical and industrial applications, say having "winner-sound qualify" according to preference criteria will be shortly in discussion.

• Journal of Drive and Control
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• v.15 no.3
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• pp.8-13
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• 2018

This paper presents a phase portrait analysis-based safety control algorithm for excavators, using adaptive sliding mode control. Since working postures and material types cause the excavator's rotational inertia to vary, the rotational inertia was estimated, and this estimation was used to design an adaptive sliding mode controller for collision avoidance of the excavator. In order to estimate the rotational inertia, the recursive least-squares estimation with multiple forgetting was applied with the information of the swing velocity of the excavator. For realistic evaluation, an actual working scenario-based performance evaluation was conducted. Based on the estimated rotational inertia and an analysis of estimation errors, sliding mode control inputs were computed. The actual working scenario-based performance evaluation of the designed safety algorithm was conducted, and the results showed that the developed safety control algorithm can efficiently avoid a collision with an object in consideration of rotational inertia variations.

• KIEE International Transactions on Power Engineering
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• v.5A no.3
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• pp.260-268
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• 2005

This paper proposes an improved investment pnonty decision method of facilities considering the reliability of distribution networks. The proposed method decides an investment order of the facilities combining, by fuzzy rules, the investment priority decision by KEPCO and that by reliability evaluation indices. The reliability evaluation indices are SAIFI (System Average Interruption Frequency Index) and SAIDI (System Average Interruption Duration Index). The reliability analysis method of distribution networks applied in this paper utilizes the analytic method, where the used reliability data is the historical data of KEPCO. Particularly, we assumed that the failure rate increases as the equipment ages. To verify the performance of the proposed method, we applied it with the planned projects to reinforce the weak electrical facilities in KEPCO in 2004. The evaluation result showed that, under a limited budget, the reliability of KEPCO in the Busan region using the proposed method could be enhanced if used rather than the conventional method typically in place. Therefore, the results verify that the proposed method can be efficiently used in the actual priorities method for investing in the electrical facilities.

• Journal of the Korean Society for Library and Information Science
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• v.49 no.1
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• pp.201-221
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• 2015

The purpose of this study is to suggest the usability of collection evaluation methods for collection development policy in public libraries. To achieve this purpose, this study applied Bonn's Use Factor, Turnover Rate of Collection, and Trueswell's 80/20 Rule to actual circulation data of the Gwangjin District Public Library in Seoul during last ten years. This study added practical meanings and values in collection evaluation through the analysis of total holdings and subject classes. Main items of analysis are the rate of use to total holdings and to holdings in specific subject classes by year, and the rate of core collection circulation by year. The results show relations between the rate of use and library's performance through the analysis of the rate of use both total holdings and subject classes. The results also figure out user's patterns and library appraisal of community users through the analysis of circulation data. In addition, the analysis of core collection gives a good basis for an effective collection development policy.

• Proceedings of the Technology Innovation Conference
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• 1998.06a
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• pp.131-163
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• 1998

The interest in the evaluation of government-sponsored research institutes (GRIs) has increased markedly in Korea in 1990s; this is mainly because of the increasing needs 1) to improve the quality of R&D at GRIs, and 2) to reorient the GRIs' strategic position in Korean national innovation systems due to the enhancement of R&D capabilities of private companies and universities during last decade. As a first attempt to diagnose the managerial and strategic issues of GRIs, a Multi-Ministerial Evaluation Committee was established as an ad hoc task force under the Prime Minister's Office in 1991. According to the recommendations of the committee, the Ministry of Science and Technology (MOST) to which most of GRIs were affiliated, made it a rule to evaluate the annual performance of GRIs since 1992. This paper examines the recent experience of MOST's evaluation of Government-sponsored Research Institute in Korea. After several years'efforts of Science & Technology Policy Institute(STEPI) to build prospective evaluation systenL MOST decided to apply two supplementary approaches for the evaluation of GRIs; one is summative annual evaluation and the other is formative 3-year evaluation. The annual evaluation system that is designed as a temporary measure is to monitor and to guide the self-evaluation activities of GRIs. In the process of annual evaluation, MOST tries to minimize its direct involvement, and allows each GRI to develop self-evaluation system that is most appropriate for the unique characteristics of the institute. If there exist urgent issues under scrutiny, however, it can be incorporated and examined by a group of external experts as special issues in the annual evaluation system. The aim of 3-year evaluation is both to examine the past performance of each GRI and to investigate whether the strategic role of each GRI is viable in the future. Its major focus, however, lies not on auditing past performance but on strengthening future strategic position of each GRI. The MOST designates a group of evaluation experts with appropriate knowledge and competence as members of the General Evaluation Committee for one year. With the help of STEPI, a specialized research institute for R&D evaluation, the General Evaluation Committee develops methodology and procedures for the actual evaluation of GRIs. Based on the evaluation reports and recommendations from the General Evaluation Committee, the MOST develops various policy measures for strengthening GRIs.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.6
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• pp.703-711
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• 2016

The purposes of this study is to identify the problems arising from current Test & Evaluation process of the naval ship acquisition program and to suggest methods to increase the acquisition efficiency. Considering that the present rule of developmental test &evaluation(DT&E) and operational test & evaluation(OT&E) has caused an inefficiency effect on the acquisition procedures due to the limited practices on it, the DT&E and OT&E procedures through test & evaluation master plan(TEMP) is proposed based on the selective practices of the defense instruction articles. Also, considering characteristics of naval ship acquisitions, efficient procedure systems are derived through case analysis results by comparing each performances of the system. The suggested methods are able to meet the requirements of the changed acquisition environments and also increase efficiency of acquisition systems by adoption of DT&E and OT&E combined test scheme.

• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.4
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• pp.101-111
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• 2014

Spatial events are predictable using data mining classification algorithms. Decision trees have been used as one of representative classification algorithms. And they were normally used in the classification tasks that have label class values. However since using rule ranking methods, spatial prediction have been applied in the spatial prediction problems. This paper compared rule ranking methods for the spatial prediction application using a decision tree. For the comparison experiment, C4.5 decision tree algorithm, and rule ranking methods such as Laplace, M-estimate and m-branch were implemented. As a spatial prediction case study, landslide which is one of representative spatial event occurs in the natural environment was applied. Among the rule ranking methods, in the results of accuracy evaluation, m-branch showed the better accuracy than other methods. However in case of m-brach and M-estimate required additional time-consuming procedure for searching optimal parameter values. Thus according to the application areas, the methods can be selectively used. The spatial prediction using a decision tree can be used not only for spatial predictions, but also for causal analysis in the specific event occurrence location.

• Journal of The Korean Association of Information Education
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• v.14 no.3
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• pp.291-300
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• 2010

Group-based learning is known to be an effective means to improve scholastic achievement in online learning. Therefore, there are some previous researches for the group-based learning. A lot of previous researches define factors for grouping from the characteristics of classes, teacher's decision and students' preferences and then generate a group based on the defined factors. However, many algorithms proposed by previous researches depend on a specific class and is not a general approach since there exist several differences in terms of the need of courses, learners, and teachers. Moreover it is hard to find a automatic system for group generation. This paper proposes a grouping system which automatically generate a learner group according to characteristics of various classes. the proposed system automatically generates a learner group by using basic information for a class or additional factors inputted from a user. The proposed system defines a set of rules for learner grouping which enables automatic selection of a learner grouping algorithm tailored to the characteristics of a given class. This rule based approach allows the proposed system to accommodate various learner grouping algorithms for a later use. Also we show the usability of our system by serviceability evaluation.

• The KIPS Transactions:PartD
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• v.17D no.1
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• pp.1-8
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• 2010

Association rule mining techniques enable us to acquire knowledge concerning sales patterns among individual items from voluminous transactional data. Certainly, one of the major purposes of association rule mining is utilizing the acquired knowledge to provide marketing strategies such as catalogue design, cross-selling and shop allocation. However, this requires too much time and high cost to only extract the actionable and profitable knowledge from tremendous numbers of discovered patterns. In currently available literature, a number of interest measures have been devised to accelerate and systematize the process of pattern evaluation. Unfortunately, most of such measures, including support and confidence, are prone to yielding impractical results because they are calculated only from the sales frequencies of items. For instance, traditional measures cannot differentiate between the purchases in a small basket and those in a large shopping cart. Therefore, some adjustment should be made to the size of market baskets because there is a strong possibility that mutually irrelevant items could appear together in a large shopping cart. Contrary to the previous approaches, we attempted to consider market basket's size in calculating interest measures. Because the devised measure assigns different weights to individual purchases according to their basket sizes, we expect that the measure can minimize distortion of results caused by accidental patterns. Additionally, we performed intensive computer simulations under various environments, and we performed real case analyses to analyze the correctness and consistency of the devised measure.

• Journal of Korea Port Economic Association
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• v.39 no.3
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• pp.179-189
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• 2023

Korea's port development adjusts the completion time and size of port facilities according to the future port throughput. The current port development system, which is referred to as "throughput-linked port development (Trigger Rule)", has received positive evaluation for efficiently executing the limited port development budget. Recently concerns have been growing over deteriorating service levels in port facilities in Korea due to accelerated aging of terminal facilities. However, the current port development system does not possess any standard for assessing the level of service and utilizing development indicators. The purpose of this paper is to calculate the Port Service Index (PSI) by selecting indicators to measure the Level of Service (LOS) of ports and deriving weights between the indicators, so that the current "throughput-linked port development (Trigger Rule)" can be linked with the level of service. Based on the result of analysis on a variety of preceding studies, the ship waiting rate, berth productivity, ship turnaround time and ship productivity were selected as four indicators to constitute the Port Service Index. The AHP and entropy methodologies were used to derive weights for each of four indicators which were later combined to calculate the comprehensive weight. The calculation formula of the Port Service Index (PSI) was derived by using the aggregated weights of each indicator, based on which the LOS of domestic container and bulk terminals were evaluated and this measurement result was divided into 6 classes to define each LOS. This paper contributes to draw the improvement measures for port development system that are able to connect the quantitative indicator of throughput, as well as a qualitative indicator of the level of "service".