• Title/Summary/Keyword: Running Performance

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Reliability of mortar filling layer void length in in-service ballastless track-bridge system of HSR

  • Binbin He;Sheng Wen;Yulin Feng;Lizhong Jiang;Wangbao Zhou
    • Steel and Composite Structures
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    • v.47 no.1
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    • pp.91-102
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    • 2023
  • To study the evaluation standard and control limit of mortar filling layer void length, in this paper, the train sub-model was developed by MATLAB and the track-bridge sub-model considering the mortar filling layer void was established by ANSYS. The two sub-models were assembled into a train-track-bridge coupling dynamic model through the wheel-rail contact relationship, and the validity was corroborated by the coupling dynamic model with the literature model. Considering the randomness of fastening stiffness, mortar elastic modulus, length of mortar filling layer void, and pier settlement, the test points were designed by the Box-Behnken method based on Design-Expert software. The coupled dynamic model was calculated, and the support vector regression (SVR) nonlinear mapping model of the wheel-rail system was established. The learning, prediction, and verification were carried out. Finally, the reliable probability of the amplification coefficient distribution of the response index of the train and structure in different ranges was obtained based on the SVR nonlinear mapping model and Latin hypercube sampling method. The limit of the length of the mortar filling layer void was, thus, obtained. The results show that the SVR nonlinear mapping model developed in this paper has a high fitting accuracy of 0.993, and the computational efficiency is significantly improved by 99.86%. It can be used to calculate the dynamic response of the wheel-rail system. The length of the mortar filling layer void significantly affects the wheel-rail vertical force, wheel weight load reduction ratio, rail vertical displacement, and track plate vertical displacement. The dynamic response of the track structure has a more significant effect on the limit value of the length of the mortar filling layer void than the dynamic response of the vehicle, and the rail vertical displacement is the most obvious. At 250 km/h - 350 km/h train running speed, the limit values of grade I, II, and III of the lengths of the mortar filling layer void are 3.932 m, 4.337 m, and 4.766 m, respectively. The results can provide some reference for the long-term service performance reliability of the ballastless track-bridge system of HRS.

Drape Simulation Estimation for Non-Linear Stiffness Model (비선형 강성 모델을 위한 드레이프 시뮬레이션 결과 추정)

  • Eungjune Shim;Eunjung Ju;Myung Geol Choi
    • Journal of the Korea Computer Graphics Society
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    • v.29 no.3
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    • pp.117-125
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    • 2023
  • In the development of clothing design through virtual simulation, it is essential to minimize the differences between the virtual and the real world as much as possible. The most critical task to enhance the similarity between virtual and real garments is to find simulation parameters that can closely emulate the physical properties of the actual fabric in use. The simulation parameter optimization process requires manual tuning by experts, demanding high expertise and a significant amount of time. Especially, considerable time is consumed in repeatedly running simulations to check the results of applying the tuned simulation parameters. Recently, to tackle this issue, artificial neural network learning models have been proposed that swiftly estimate the results of drape test simulations, which are predominantly used for parameter tuning. In these earlier studies, relatively simple linear stiffness models were used, and instead of estimating the entirety of the drape mesh, they estimated only a portion of the mesh and interpolated the rest. However, there is still a scarcity of research on non-linear stiffness models, which are commonly used in actual garment design. In this paper, we propose a learning model for estimating the results of drape simulations for non-linear stiffness models. Our learning model estimates the full high-resolution mesh model of drape. To validate the performance of the proposed method, experiments were conducted using three different drape test methods, demonstrating high accuracy in estimation.

A Study on the Exercise Adherence of the Elderly Woman at Non-Commercial Sports Centers (비영리 사회체육시설 이용 여성고령자의 운동지속에 관한 연구)

  • Yun, Man-soo;Choi, Chang-Sick;Kang, Jean-Hong
    • 한국노년학
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    • v.27 no.2
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    • pp.487-502
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    • 2007
  • An objective of this study is to verify factor of exercise adherence of the elder who have carried on exercise for many years at non-commercial sports center. To achieve the objective, I used ethnography, a method of qualitative study. The subjects for this study were 5 members of non-commercial sports center. They have been attending lesson which I have been running Taichi for more than 2 years and carried on exercise for more than 5 years. Main results of this study are as follows. First, the elder who have kept on with exercise showed the eagerness to participate and capacity of self-management through their exercise adherence for many years. Second, various factors such as social, environmental, and social psychological on had a strong effect on a continuous exercise performance. The most remarkable thing of results of this study is a close human connection among instructors, manager and companion is the most effectual factor of the elder's exercise adherence.

Analysis of Flexural Behavior of Composite Beam with Steel Fiber Reinforced Ultra High Performance Concrete Deck and Inverted-T Shaped Steel with Tension Softening Behavior (인장연화거동을 고려한 강섬유 보강 초고성능 콘크리트 바닥판과 역T형 강재 합성보의 휨거동 해석)

  • Yoo, Sung-Won;Yang, In-Hwan;Jung, Sang-Hwa
    • Journal of the Korea Concrete Institute
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    • v.27 no.2
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    • pp.185-193
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    • 2015
  • Ultra high performance concrete (UHPC) has been developed to overcome the low tensile strengths and brittleness of conventional concrete. Considering that UHPC, owing to its composition and the use of steel fibers, develops a compressive strength of 180 MPa as well as high stiffness, the top flange of the steel girder may be superfluous in the composite beam combining a slab made of UHPC and the steel girder. In such composite beam, the steel girder takes the form of an inverted-T shaped structure without top flange in which the studs needed for the composition of the steel girder with the UHPC slab are disposed in the web of the steel girder. This study investigates experimentally and analytically the flexural behavior of this new type of composite beam to propose details like stud spacing and slab thickness for further design recommendations. To that goal, eight composite beams with varying stud spacing and slab thickness were fabricated and tested. The test results indicated that stud spacing running from 100 mm to 2 to 3 times the slab thickness can be recommended. In view of the relative characteristic slip limit of Eurocode-4, the results showed that the composite beam developed ductile behavior. Moreover, except for the members with thin slab and large stud spacing, most of the specimens exhibited results different to those predicted by AASHTO LRFD and Eurocode-4 because of the high performance developed by UHPC.

Experiment of Flexural Behavior of Composite Beam with Steel Fiber Reinforced Ultra High Performance Concrete Deck and Inverted-T Steel Girder (강섬유로 보강된 초고성능 콘크리트 바닥판과 역T형 강거더 합성보의 휨거동 실험)

  • Yoo, Sung-Won;Ahn, Young-Sun;Cha, Yeong-Dal;Joh, Chang-Bin
    • Journal of the Korea Concrete Institute
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    • v.26 no.6
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    • pp.761-769
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    • 2014
  • Ultra high performance concrete (UHPC) has been developed to overcome the low strengths and brittleness of conventional concrete. Considering that UHPC, owing to its composition and the use of steel fibers, develops a compressive strength of 180 MPa as well as high stiffness, the top flange of the steel girder may be superfluous in the composite beam combining a slab made of UHPC and the steel girder. In such composite beam, the steel girder takes the form of an inverted-T shaped structure without top flange in which the studs needed for the composition of the steel girder with the UHPC slab are disposed in the web of the steel girder. This study investigates experimentally and analytically the flexural behavior of this new type of composite beam to propose details like stud spacing and slab thickness for further design recommendations. To that goal, eight composite beams with varying stud spacing and slab thickness were fabricated and tested. The test results indicated that stud spacing running from 100 mm to 2 to 3 times the slab thickness can be recommended. In view of the relative characteristic slip limit of Eurocode-4, the results showed that the composite beam developed ductile behavior. Moreover, except for the members with thin slab and large stud spacing, most of the specimens exhibited results different to those predicted by AASHTO LRFD and Eurocode-4 because of the high performance developed by UHPC.

Research Framework for International Franchising (국제프랜차이징 연구요소 및 연구방향)

  • Kim, Ju-Young;Lim, Young-Kyun;Shim, Jae-Duck
    • Journal of Global Scholars of Marketing Science
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    • v.18 no.4
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    • pp.61-118
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    • 2008
  • The purpose of this research is to construct research framework for international franchising based on existing literature and to identify research components in the framework. Franchise can be defined as management styles that allow franchisee use various management assets of franchisor in order to make or sell product or service. It can be divided into product distribution franchise that is designed to sell products and business format franchise that is designed for running it as business whatever its form is. International franchising can be defined as a way of internationalization of franchisor to foreign country by providing its business format or package to franchisee of host country. International franchising is growing fast for last four decades but academic research on this is quite limited. Especially in Korea, research about international franchising is carried out on by case study format with single case or empirical study format with survey based on domestic franchise theory. Therefore, this paper tries to review existing literature on international franchising research, providing research framework, and then stimulating new research on this field. International franchising research components include motives and environmental factors for decision of expanding to international franchising, entrance modes and development plan for international franchising, contracts and management strategy of international franchising, and various performance measures from different perspectives. First, motives of international franchising are fee collection from franchisee. Also it provides easier way to expanding to foreign country. The other motives including increase total sales volume, occupying better strategic position, getting quality resources, and improving efficiency. Environmental factors that facilitating international franchising encompasses economic condition, trend, and legal or political factors in host and/or home countries. In addition, control power and risk management capability of franchisor plays critical role in successful franchising contract. Final decision to enter foreign country via franchising is determined by numerous factors like history, size, growth, competitiveness, management system, bonding capability, industry characteristics of franchisor. After deciding to enter into foreign country, franchisor needs to set entrance modes of international franchising. Within contractual mode, there are master franchising and area developing franchising, licensing, direct franchising, and joint venture. Theories about entrance mode selection contain concepts of efficiency, knowledge-based approach, competence-based approach, agent theory, and governance cost. The next step after entrance decision is operation strategy. Operation strategy starts with selecting a target city and a target country for franchising. In order to finding, screening targets, franchisor needs to collect information about candidates. Critical information includes brand patent, commercial laws, regulations, market conditions, country risk, and industry analysis. After selecting a target city in target country, franchisor needs to select franchisee, in other word, partner. The first important criteria for selecting partners are financial credibility and capability, possession of real estate. And cultural similarity and knowledge about franchisor and/or home country are also recognized as critical criteria. The most important element in operating strategy is legal document between franchisor and franchisee with home and host countries. Terms and conditions in legal documents give objective information about characteristics of franchising agreement for academic research. Legal documents have definitions of terminology, territory and exclusivity, agreement of term, initial fee, continuing fees, clearing currency, and rights about sub-franchising. Also, legal documents could have terms about softer elements like training program and operation manual. And harder elements like law competent court and terms of expiration. Next element in operating strategy is about product and service. Especially for business format franchising, product/service deliverable, benefit communicators, system identifiers (architectural features), and format facilitators are listed for product/service strategic elements. Another important decision on product/service is standardization vs. customization. The rationale behind standardization is cost reduction, efficiency, consistency, image congruence, brand awareness, and competitiveness on price. Also standardization enables large scale R&D and innovative change in management style. Another element in operating strategy is control management. The simple way to control franchise contract is relying on legal terms, contractual control system. There are other control systems, administrative control system and ethical control system. Contractual control system is a coercive source of power, but franchisor usually doesn't want to use legal power since it doesn't help to build up positive relationship. Instead, self-regulation is widely used. Administrative control system uses control mechanism from ordinary work relationship. Its main component is supporting activities to franchisee and communication method. For example, franchisor provides advertising, training, manual, and delivery, then franchisee follows franchisor's direction. Another component is building franchisor's brand power. The last research element is performance factor of international franchising. Performance elements can be divided into franchisor's performance and franchisee's performance. The conceptual performance measures of franchisor are simple but not easy to obtain objectively. They are profit, sale, cost, experience, and brand power. The performance measures of franchisee are mostly about benefits of host country. They contain small business development, promotion of employment, introduction of new business model, and level up technology status. There are indirect benefits, like increase of tax, refinement of corporate citizenship, regional economic clustering, and improvement of international balance. In addition to those, host country gets socio-cultural change other than economic effects. It includes demographic change, social trend, customer value change, social communication, and social globalization. Sometimes it is called as westernization or McDonaldization of society. In addition, the paper reviews on theories that have been frequently applied to international franchising research, such as agent theory, resource-based view, transaction cost theory, organizational learning theory, and international expansion theories. Resource based theory is used in strategic decision based on resources, like decision about entrance and cooperation depending on resources of franchisee and franchisor. Transaction cost theory can be applied in determination of mutual trust or satisfaction of franchising players. Agent theory tries to explain strategic decision for reducing problem caused by utilizing agent, for example research on control system in franchising agreements. Organizational Learning theory is relatively new in franchising research. It assumes organization tries to maximize performance and learning of organization. In addition, Internalization theory advocates strategic decision of direct investment for removing inefficiency of market transaction and is applied in research on terms of contract. And oligopolistic competition theory is used to explain various entry modes for international expansion. Competency theory support strategic decision of utilizing key competitive advantage. Furthermore, research methodologies including qualitative and quantitative methodologies are suggested for more rigorous international franchising research. Quantitative research needs more real data other than survey data which is usually respondent's judgment. In order to verify theory more rigorously, research based on real data is essential. However, real quantitative data is quite hard to get. The qualitative research other than single case study is also highly recommended. Since international franchising has limited number of applications, scientific research based on grounded theory and ethnography study can be used. Scientific case study is differentiated with single case study on its data collection method and analysis method. The key concept is triangulation in measurement, logical coding and comparison. Finally, it provides overall research direction for international franchising after summarizing research trend in Korea. International franchising research in Korea has two different types, one is for studying Korean franchisor going overseas and the other is for Korean franchisee of foreign franchisor. Among research on Korean franchisor, two common patterns are observed. First of all, they usually deal with success story of one franchisor. The other common pattern is that they focus on same industry and country. Therefore, international franchise research needs to extend their focus to broader subjects with scientific research methodology as well as development of new theory.

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Effects of Secondary Task on Driving Performance -Control of Vehicle and Analysis of Motion signal- (동시과제가 운전 수행 능력에 미치는 영향 -차량 통제 및 동작신호 해석을 중심으로-)

  • Mun, Kyung-Ryoul;Choi, Jin-Seung;Kang, Dong-Won;Bang, Yun-Hwan;Kim, Han-Soo;Lee, Su-Jung;Yang, Jae-Woong;Kim, Ji-Hye;Choi, Mi-Hyun;Ji, Doo-Hwan;Min, Byung-Chan;Chung, Soon-Cheol;Taek, Gye-Rae
    • Science of Emotion and Sensibility
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    • v.13 no.4
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    • pp.613-620
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    • 2010
  • The purpose of this study was to quantitatively evaluate the effects of the secondary task while simulated driving using the variable indicating control of vehicle and smoothness of motion. Fifteen healthy adults having 1~2years driving experience were participated. 9 markers were attached on the subjects' upper(shoulder, elbow, Wrist) and lower(knee, ankle, toe) limbs and all subjects were instructed to keep the 30m distance with the front vehicle running at 80km/hr speed. Sending text message(STM) and searching navigation(SN) were selected as the secondary task. Experiment consisted of driving alone for 1 min and driving with secondary task for 1 min, and was defined driving and cognition blocks respectively. To indicate the effects of secondary task, coefficient of variation of distance between vehicles and lane keeping(APCV and MLCV) and jerk-cost function(JC) were analyzed. APCV was increased by 222.1% in SN block. MLCV was increased by 318.2% in STM and 308.4% in SN. JC were increased at the drivers' elbow, knee, ankle and toe, especially the total mean JC of lower limbs were increased by 218.2% in STM and 294.7% in SN. Conclusively, Performing secondary tasks while driving decreased the smoothness of motion with increased JC and disturbed the control of vehicle with increased APCV and MLCV.

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Effect of the Characteristics of Organizational Support on Company HRD Education & Training Program (기업 HRD 교육훈련 프로그램의 조직지원 특성에 따른 효과성)

  • Ryu, Seok-Woo;Yang, Hea-Sool
    • The Journal of the Korea Contents Association
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    • v.12 no.6
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    • pp.497-507
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    • 2012
  • This study aims to verify how the characteristics of organizational supporting unit affect the effectiveness of company-wide HRD Education & Training program. To achieve this objective, we performed an empirical analysis, with the characteristics of organizational supporting unit comprising supervisor's support, job support, and company support as independent variables, and with the level of reaction stage, learning stage, transfer stage, and result stage as dependent variables. Empirical data was collected during the period from August 16, 2011 to September 9, 2011 by sending out questionnaires to employees of 5 securities firms listed on KOSDAQ where online and offline education & training program is running year-round with headquarter in Seoul. A total of 340 questionnaires were sent out three times for the survey, and total of 164 questionnaires were sampled for the final analysis. According to the outcome of the analysis, regarding the first hypothesis that tries to reveal how the characteristics affect the level of reaction stage, it is verified that all of supervisor's support, job support and company support have positive impact on the level of reaction stage with p value less than 0.01. In regard to the second hypothesis that tries to see how the characteristics affect the level of learning stage, it is confirmed that supervisor's support, job support and company support have significant impact on the level of learning stage with p value less than 0.05 or 0.01, respectively. Concerning the third hypothesis that aims to investigate how the characteristics affect the level of transfer stage, it is appeared that all of supervisor's support, job support and company support have positive impact on the level of transfer stage. And lastly, as for the fourth hypothesis that tries to see how the characteristics affect the level of result stage, it is analyzed that supervisor's support, job support and company support have positive impact on the level of result stage with p value less than 0.01. This study reconfirm the outcomes of previous research, which is that the effectiveness of company-wide education & training program depends not only on the contents and quality of education & training program, but also more importantly on the role of organizational supporting unit, and the working environment where what is learned in classroom can be applied to real business. Companies or experts that run education & training program in real world should recognize that the performance of training is dependent more significantly on the characteristics of organizational supporting unit rather than the design or features of education & training program.

A Study on the Psychopharmacological Actions of Panax ginseng in Animals (인삼의 향정신작용에 관한 연구)

  • Hong, Sa-Ack;Kim, Myeong-Seok;Jang, Hyeon-Gap
    • Journal of Ginseng Research
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    • v.1 no.1
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    • pp.33-50
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    • 1976
  • As a continuation of series of works on the pharmacological actions of Panax ginseng. three kinds of behavioral experiments were carried out using rats and mice. The occurrence of component Posterns of general behavioral activity in rat was examined by visual scanning using the ting sample method in the ad lib. And he hunger deprivated situation. In normal ad lib. situation, the eating behavior of rat treated with 100mg/kg of ginseng saponin was significantly more frequent than that of saline control at the night and throughout the 24 hr period. But grooming was less frequent than the control at the same period. In the hunger situation followed by 90~120 hrs of feed deprivation, the locomotive activity and rearing awe significantly more often and sleeping was less frequent in the two dosage g roups of ginseng saponin (10 and 100 mg/kg) than in the saline group though out the observation period. Training of avoidance conditioning in rats was done in a two-way shuttle box. The number of conditioned response (CR) in which the animal avoided sucessfully an electric shock by running in to the other compartment of the hex was regarded as an index of learning performance. Ginseng saponin in doses of 2.5 mg/kg Produced a significantly increased CR in total avoidance tria1s compared with the control. Although other dosage groups of ginseng saponin (5.0, 50mg and 100 mg/kg) showed no significant statistical difference from the normal control, it tended to increase in CR in the ginseng groups than in the control. An aggressive behavior in mice was observed in n shock-generating fighting box. The occurrence of reflexive fighting between two animals induced by an electric shock applied to the feet war checked as an index of aggression. The occurrence of reciprocal fighting episode immediately after the onset. Of the shock was significantly decreased in the dosage group of 400 mg/kg ginseng saponin, but it did net differ in the 100 mg/kg group of ginseng saponin from the control group. The dose, 400 mg/kg of ginseng saponin, inhibited fighting behavior in more than 80% of the Pairs. but 100 mg/kg of ginseng did inhibit it in less than 20% of the pairs.

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Effect of Reversible Air-circulation Fans on Air Uniformity in a Cultivation Facility for Oyster Mushroom (느타리재배사 정역 제어 대류팬이 공기 균일도에 미치는 영향)

  • Yum, Sung Hyun;Kim, Si Hwan
    • Journal of Bio-Environment Control
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    • v.30 no.4
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    • pp.383-392
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    • 2021
  • It has been known that oyster mushrooms cultivated in facilities with thermal insulation have been strongly affected by inner environments. Forced air-circulation fans exert much direct influence on disturbing air inside the facility so the matter is of particular interest. This study is carried out to investigate the measured levels of air uniformity in a cultivation facility for oyster mushroom in the various cases that reversibly controlled air-circulation fans which drove the flow in the upward and reverse direction by turn and unidirectional fans by which the wind blew upwards only were operated from July 1 to 10. The actual survey for the selection of ongoing operation cases presented that farmers, even though there were some discrepancies, have made use of fans in a way that it paused for 5-30min after running for 5-15min by turn. The level of air uniformity in the case of adopting reversible fans revealed a slight difference of 1.4-1.8℃ (Temp.) and 7.8-8.7% (R.H.) under the condition of not using a cooler during the investigation period. By contrast, unidirectional fans showed a noticeable difference of 3.2-3.7℃ and 14.0-15.4%, which meant that air uniformity driven by reversible fans much more increased compared to that for unidirectional fans. Among the twenty operational applications considered for reversible fans, the circumstance that the wind blew upwards for 10-15min and ceased for 5-10min and blew again in the reverse direction for 10-15min in succession gave minor improvements at the level of air uniformity, but at present there was somewhat difficult to make decision on which cases were optimally best. It seems necessary that the effects of reversible fans on air uniformity as well as qualities of oyster mushrooms have to be appraised in the cultivation period and the flow visualization needs to be done to ascertain the performance of air mixture.