• Title/Summary/Keyword: 핵심 변수

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Design to Reduce Structure-borne Noise in Outdoor Unit of Air Conditioner Using Structural Optimization with Frequency Constraints (고유진동수 제약식을 갖는 구조 최적화를 통한 에어컨 실외기의 구조기인소음 저감 설계)

  • 최상현;박남규;박윤식
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.11a
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    • pp.179-184
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    • 2001
  • 대부분의 제품 생산 시에는 시제품을 제작하여 이에 대한 성능 심사를 통해 미비한 부분을 보완하기 위한 재설계 작업과정을 필요로 한다. 설계 작업에 가장 중요한 부분인 특정 설계 변수에 대한 민감도의 파악은 설계 작업의 핵심적인 역할을 하고 있다. 대개의 경우 진동설계를 위한 설계변수로 구조물의 단위면적, 길이, 재료의 성질과 같은 물리적인 변수를 많이 활용하고 있으며 이러한 변수들에 대한 민감도 해석 기법들은 이미 많은 연구를 통해 실용화되고 있다. 그러나 이러한 변수만으로는 주어진 조건을 만족하도록 설계하기가 어려운 경우가 있다. 이런 경우는 부가구조물을 첨가하여 저진동 설계조건을 만족하는 구조물을 제작하는 것이 보편적이다. 한편, 구조물의 최적화 과정에서 고유진동수를 고려해야 하는 경우가 많다. 저주파 영역의 문제에서는 첫번째 고유진동수가 구조물의 진동량에 관계되는 중요한 요인이 되고, 또한 공진에 의한 문제가 발생했을 경우에는 고유진동수를 옮겨서 공진을 회피할 수 있기 때문이다. 본 연구에서는 에어컨 실외기의 진동을 저감하고 그로 인한 구조기인 소음을 저감하기 위하여 음압 레벨을 바탕으로 정한 관심 주파수 영역에 고유진동수가 존재하지 않도록 부가구조물을 최적화하였다. 최적화에 필요한 민감도는 신뢰성 있는 유한요소 모델을 구성하는 것이 쉽지 않으므로 실험으로 구한 주파수 응답함수를 이용하였다.

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Diagnosis by Rough Set and Information Theory in Reinforcing the Competencies of the Collegiate (러프집합과 정보이론을 이용한 대학생역량강화 진단)

  • Park, In-Kyoo
    • Journal of Digital Convergence
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    • v.12 no.8
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    • pp.257-264
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    • 2014
  • This paper presents the core competencies diagnosis system which targeted our collegiate students in an attempt to induce the core competencies for reinforcing the learning and employment capabilities. Because these days data give rise to a high level of redundancy and dimensionality with time complexity, they are more likely to have spurious relationships, and even the weakest relationships will be highly significant by any statistical test. So as to address the measurement of uncertainties from the classification of categorical data and the implementation of its analytic system, an uncertainty measure of rough entropy and information entropy is defined so that similar behaviors analysis is carried out and the clustering ability is demonstrated in the comparison with the statistical approach. Because the acquired and necessary competencies of the collegiate is deduced by way of the results of the diagnosis, i.e. common core competencies and major core competencies, they facilitate not only the collegiate life and the employment capability reinforcement but also the revitalization of employment and the adjustment to college life.

Comparison of Smart City Efficiency Using DEA and KPI

  • Sang-Ho Lee;Hee-Yeon Jo;Yun-Hong Min
    • Journal of the Korea Society of Computer and Information
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    • v.29 no.1
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    • pp.97-109
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    • 2024
  • This research aims to investigate how major cities in Korea utilize smart city-related technologies, develop key performance indicators (KPIs) to measure the smartness and efficiency of cities, and propose a methodology for assessing and suggesting smart city policy directions based on Data Envelopment Analysis (DEA). Referring to the CITYkeys Smart City Performance Measurement Framework, 10 key performance indicators (KPIs) were derived. For each KPI, city statistical data were allocated to input and output variables, and 15 cities were assigned as Decision Making Units (DMUs). The DEA methodology was employed to evaluate the operational efficiency and scale profitability of cities, providing insights into the operational efficiency of each city. Finally, the operational efficiency among DMUs was ranked to propose smart city policy directions for each city.

Fuzzy Regression Analysis for Core Competency of Construction Subcontractors (건설협력업체 핵심역량의 퍼지회귀분석)

  • Kim, Seong-Il;Hwang, Seung-Gook
    • Journal of the Korean Institute of Intelligent Systems
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    • v.25 no.3
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    • pp.203-209
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    • 2015
  • In this paper, we conducted a conventional regression and fuzzy regression analysis of the core competencies of construction subcontractors. The study was undertaken to check whether these two types of regression core capabilities affect the rating of construction subcontractor. Conventional regression result showed some effect on the rating of construction subcontractors on which core competencies to management and firm contribution were conducted. With fuzzy regression analysis, on the other hand, the rating of construction subcontractors could see the Min and Conjunction problem which utilize 100% reliability of Min. Max and Conjunction. From the above, the dependent variable of conventional regression could determine the evaluation grade of construction subcontractor. The fuzzy regression analysis shows the estimator of evaluation grade of the construction subcontractor including or corresponding to the fuzzy output data.

A Convergence Study on the Effects of Core Nursing Skills Improvement Program on Nursing Skills Competence in Nursing Students (핵심간호술 강화프로그램이 간호학생의 간호술 수행능력에 미치는 효과에 관한 융합연구)

  • Ha, Young-ok;An, Ji-Yoen
    • Journal of the Korea Convergence Society
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    • v.8 no.5
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    • pp.223-231
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    • 2017
  • This convergence study was done to identify the effectiveness of core nursing skills improvement program on nursing skills competence in nursing students. The design of research was one group pretest-posttest and the participants were 158 nursing students. The core nursing skills improvement program was composed of 7 fundamental nursing skills(vital sign, intramuscular injection, oral medication, subcutaneous injection, enema, oxygen therapy and nelaton). The data were collected using self-report questionnaires from January 19 to 23, 2015 and analyzed using paired t-test. The mean score of nursing skills competence in posttest was significantly higher than those in pretest (t=-4.71 ~ -8.00, p<.001). The score for self-confidence(t=-11.61, p<.001) and that for problem solving skills(t=-2.04, p=.043) increased significantly after core nursing skills improvement program. The results indicate that core nursing skills improvement program was effective in improving nursing skills competence.

A Study on Discriminant Factors of Political Orientation of Korean People: Focusing upon Welfare Attitudes (한국인의 정치적 성향 판별요인 분석: 복지태도를 중심으로)

  • Sin-Young Kim
    • The Journal of the Convergence on Culture Technology
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    • v.10 no.3
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    • pp.227-231
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    • 2024
  • This study purports to examine the potential effects of welfare attitudes of Korean people upon their political orientation. The 17th Korea Welfare Panel Data(KWPD) in 2022 are used for this purpose. Independent variable include sex, age, education, interest in politics, and employment status. Discriminant analysis show several results. First and foremost, pre-established discriminant function works well for classification of respondents' liberal vs conservative stance. Secondly, except gender and dummy variable for temporary employed, all independent variables contribute significantly for the classification at a given significance level. . Finally, welfare attitudes of respondents', measured by universalism vs selectivism and the attitudes upon increasing tax for welfare expenditures are found to be significant and relatively big impacts upon dependent variable, compard to other variables in the model. The nature of causal relationship between welfare attitudes and political orientation remains for further study.

An Empirical Study on Comparative Analysis of Determinants of Management Performance for Domestic Ventures (국내 벤처의 경영성과 영향요인 비교 분석에 관한 실증연구)

  • Lee, Sang-Cheon;Bae, Sung-Moon;Go, Bong-Sang
    • The Journal of Society for e-Business Studies
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    • v.13 no.4
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    • pp.145-159
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    • 2008
  • The purpose of this study is to identify the determinants of new venture performance in the view of integrated research framework and to investigate key determinants of superior and inferior ventures. We propose the integrated new ventures performance model which is composed of entrepreneur, organization/resources, industrial environment, strategy/foundation process and availability of supporting systems as corresponding variables to new ventures performance. The superior venture performance is affected mainly by entrepreneur's managerial ability and industry expertise, but the inferior by resources and management strategy. Though this study has limitation of small sample, limited questionnaire and performance measure, it has contribution of identifying key determinants of new venture performance with the integrated frame of study.

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An Analysis of the Authentic Inquiry Components in Science Inquiry Experiments Textbooks Developed Under the 2015 Revised National Curriculum (2015 개정 교육과정에 따른 과학탐구실험 교과서에 나타난 참탐구 요소 분석)

  • Lee, Jaewon;Lee, Kyuyul;An, Jihyun
    • Journal of the Korean Chemical Society
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    • v.63 no.3
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    • pp.183-195
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    • 2019
  • In this study, we investigated the characteristics of the authentic inquiry components in the inquiry tasks of Science Inquiry Experiments textbooks developed under the 2015 Revised National Curriculum. After classifying inquiry tasks by core concepts, we analyzed the cases that students autonomously planned or performed the authentic inquiry components. The results of the study revealed that investigating multiple materials component most frequently appeared in all units. However, generating research question, selecting variables, observing multiple variables and transforming observations components appeared in a few tasks of history and everyday science units as they were often guided or structured in textbooks. Controlling simple or complex variables, observing intervening variables and considering methodological flaws components rarely appeared in all units as most of textbooks did not consider or indicate explicitly. Authentic inquiry components of everyday science unit tended to be handled in small group activities. On the bases of the results, the implications for the development of the inquiry tasks of Science Inquiry Experiments textbooks are discussed.

Fundamental Study on Rock Cutting by an Actuated Undercutting Disc (구동형 언더커팅 디스크에 의한 암석절삭에 관한 기초연구)

  • Jeong, Hoyoung;Wicaksana, Yudhidya;Kim, Sehun;Jeon, Seokwon
    • Tunnel and Underground Space
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    • v.30 no.6
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    • pp.591-602
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    • 2020
  • Several alternative rock-cutting concepts, which are modified from the conventional ones, have been developed lately. Of the concepts, undercutting is one of the latest technologies. In this study, as a fundamental study on the undercutting technique, the rock-cutting mechanism and important parameters of the undercutting were introduced. This study built up cutting test system for evaluating the cutting performance of an actuated undercutting disc cutter (ADC), and carried out a series of cutting tests under different cutting parameters of ADC. The characteristics of cutter forces obtained from ADC rock-cutting tests were analyzed. The both average and peak values of the three directional cutter forces were linearly increased with the increases of linear velocity, penetration depth in vertical direction and eccentricity of ADC.

Impact of High Potential Employee System on Corporate Performance - Focused on Moderating Effect of Competitive Strategy and Technological Environment (핵심인재관리제도가 기업성과에 미치는 영향 - 경쟁전략 및 기술환경의 조절효과를 중심으로 -)

  • Jeon, Dong-Hwa;Chung, Dong-Seop
    • Management & Information Systems Review
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    • v.30 no.4
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    • pp.315-338
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    • 2011
  • A "high-potential employee" is an employee who has been identified as having the potential, ability and aspiration for successive leadership positions within the company and identify employees who have the greatest future potential and make them future-ready to take your organization to success. The primary purpose of this paper is to investigate the relationships of corporate performance on the high potential employee system using the samples from HCCP panel data. This study seeks to identify a significant high potential employee system though empirical research as well. Results of empirical study are summarized. Finally suggestions, implications and limitations of the present study are also discussed. In this article, we explore the role of competitive strategy and technological environment in the introduction of high-potential employees and its link to impact of these performance.

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