• Title/Summary/Keyword: frequency problem

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Social Dependence of Problem Drinking (알코올문제의 사회적 의존에 대한 소고)

  • 김광기
    • Korean Journal of Health Education and Promotion
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    • v.12 no.2
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    • pp.146-161
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    • 1995
  • This study is an effort to bring our attention to social dependence on alcohol, focusing on previous studies of drinking behaviors. Although drinking behavior and problems must be understood in a biopsychosocial framework, a certain aspect is often ignored in alcohol research. A few attention has been paid to social aspect of alcohol abuse or dependence. Social processes of drinking behavior deserve to have same attention as other aspects, psychological and physical aspects of the behavior. Literature show that the interdependence among group members exists to regulate individual's drinking behavior. Such social interactions tend to control drinking level for individual in terms of amounts, frequency, and preference. The drinking level tends to be dependent on desires for heavy drinkers, ignoring variabilities of individual's sensitivity to alcohol. However, such a heavy-oriented tendency in drinking behavior may have different patterns which are function of normative orientation of alcohol. negotiation among group members, and ethnoreligious characteristics. Perspectives from conflict tradition and symbolic interactionism are welcomed to illuminate multi-dimentional aspects of social dependence. Policy implication were discussed from public health perspective.

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Consumers Preference and Dissatisfaction on knitted Golf Wear (골프니트웨어의 소비자 선호도와 불만족에 관한 연구)

  • 신상무;이종림
    • Journal of the Korean Society of Costume
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    • v.51 no.4
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    • pp.97-112
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    • 2001
  • The purposes of this study were to investigate consumers preference and dissatisfied factors in knitted golf wear The 430 questionnaires were sent to consumers who live in the Seoul Metropolitan district including Pundang-city and Iisan-city, The return rate was 89.5%. Statistical devices were t-test, ANOVA, $X$2. frequency with SAS program. The results of this study were as follows: First, Preferred colors were pastel, straw yellow, and black in descending order. Preferred coordination was analogous rather than complementary coordination. The classical look with T-neck, pullover, and V-neck was preferred. The preferred materials were pure cotton and cotton/wool blend in solid colors or plain and intasia structure. There were significant differences that pure cotton was preferred the forties and fifties or housewife, and cotton blend was preferred the thirties or service jobholders. Second, dissatisfied factors were pilling, deformation and de-coloration. The pilling problem was indicated in all income levels. Customers complained about no exchange and no refund policy with sales persons'discourtesy and time delay for repairing.

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A study on the vibration calculation method of portal frame structure with variable sections (변화하는 단면의 문형구조물의 진동계산에 관한 연구)

  • 조용수;전효중
    • Journal of Advanced Marine Engineering and Technology
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    • v.9 no.3
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    • pp.214-224
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    • 1985
  • In this paper, some theoretical equations are derived to calculate natural frequencies and their modes of a portal type derrick system and developed a computer program to carry out their calculations. The ship's structures, such as funnels, upper decks, engine structures, shaft systems suffer local vibrations of the ship. The exciting forces of vibrations are induced by the bearing force and the surface force of propeller or by the main engine. For solving the vibration problem of riggings like the derrick system the natural frequency of its system must be exactly estimated as far as possible and its resonance condition must be kept out of the normal engine operating speed range. When some severe resonances are encountered after the ship's launching, it may be required a tremendous cost to amend their condition. An experimental model of the portal type derrick is made, which is composed of two posts and a truss. This experimental model is excited by an electrical-magnet, and its vibration responses are found out. The calculating results of the model by the developed computer program are compared with those of measured values of model experiment, and they show fairly good agreements.

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Substructure Synthesis Method using Dynamic Reduction (동축소법을 이용한 부분구조합성법)

  • 박석주;박성현;김성우
    • Journal of Advanced Marine Engineering and Technology
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    • v.24 no.1
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    • pp.82-87
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    • 2000
  • The component mode synthesis method(CMS) used for vibration analysis has demerit that error becomes larger, as degree of natural frequency grows higher. The reason of error occurrence is that Guyan's static reduction is used and the number of modes taken in each component is deficient. This paper proposes the substructure synthesis method using dynamic reduction to solve the problem from the component mode synthesis method. Computer simulation for the proposed method. FEM and the component mode synthesis method(CMS) on a rectrangular plate has been carried out to prove the avilability of the proposed method.

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Non-Stationary Response of a Vehicle Obtained From a Series of Stationary Responses

  • Karacay, Tuncay;Akturk, Nizami;Eroglu, Mehmet;Ba
    • Journal of Mechanical Science and Technology
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    • v.18 no.9
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    • pp.1565-1571
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    • 2004
  • Ride characteristics of a vehicle moving on a rough ground with changing travel velocity are analyzed in this paper. The solution is difficult due to the non-stationary characteristics of the problem. Hence a new technique has been proposed to overcome this difficulty. This new technique is employed in the analysis of ride characteristics of a vehicle with changing velocity in the time/frequency domain. It is found that the proposed technique gives successful results in modelling non-stationary responses in terms of a series of stationary responses.

Residual Vibration Reduction of Precise Positioning Stage Using Virtual-Mode Based Input Shapers (가상모드 입력성형기를 이용한 위치결정 스테이지 잔류진동 저감)

  • Seo, Yong-Gyu;Jang, Joon-Won;Hong, Seong-Wook
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.18 no.3
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    • pp.255-260
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    • 2009
  • This paper presents an experimental result of virtual mode input shaping for positioning stage. Input shaping is liable to increase the rise time of the system, which often degrades the performance of system. The virtual mode input, shaping is an input shaper design method to improve this problem. Experiments are performed with a precise positioning stage with a flexible beam of which natural frequency is adjustable. The experimental results show that the virtual-mode shaper is useful to reduce the rise time as well as the residual vibration of precise positioning stages.

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Study on Dynamic Characteristics of Spindle-bearing System Subjected to Radial Load (경방향 하중을 받는 스핀들 베어링 계의 동특성 연구)

  • Choi, Chun-Suk;Hong, Seong-Wook
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.22 no.4
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    • pp.740-746
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    • 2013
  • Angular contact ball bearings are often adopted for a high-speed spindle owing to their durability against axial and radial loads. The dynamic characteristics of an angular contact ball bearing, however, are very complicated because they are dependent on the applied loads as well as on the system configuration. This study systematically analyzes the radial-load-dependent characteristics of spindles as well as angular contact ball bearings. Toward this end, a spindle dynamic model along with the bearing dynamics model is established. An iterative solution algorithm is implemented to resolve the statically indeterminate problem associated with spindle-bearing systems subjected to radial load. Two numerical examples are provided to investigate the spindle and bearing characteristics as a function of radial load with regard to the system configuration.

Torsional free vibration analysis of heavy duty powertrain (대형트럭 구동계의 비틀림 자유진동해석)

  • Ahn, Byoung-Min;Hong, Dong-Pyo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.22 no.2
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    • pp.437-443
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    • 1998
  • Automobile company tries to reduce the inertia of powertrain to increase the fuel efficiency and increase the engine power every year to make the high speed driving possible at full load condition. These cause the torsional vibration of powertrain. But the demand about ride comfort improvement is increased constantly, so torsional vibration of powertrain become an emergency problem to be cured. This study is a basic research to reduce the torsional vibration of powertrain at driving condition. First, the heavy duty powertrain is characterized as a vibrating system. Its natural frequencies and mode shapes are reviewed. Second, by comparison of simulation results and experiment results, validity of developed model is verified. Finally, the couterplan which can reduce the torsional vibration by mode analysis and parameter modification is suggested.

Issues Related to RFID Security and Privacy

  • Kim, Jong-Ki;Yang, Chao;Jeon, Jin-Hwan
    • 한국경영정보학회:학술대회논문집
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    • 2007.06a
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    • pp.951-958
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    • 2007
  • Radio Frequency Identification (RFID) is a technology for automated identification of objects and people. RFID may be viewed as a means of explicitly labeling objects to facilitate their "perception" by computing devices. RFlD systems have been gaining more popularity in areas especially in supply chain management and automated identification systems. However, there are many existing and potential problems in the RFlD systems which could threat the technology s future. To successfully adopt RFID technology in various applications. we need to develop the solutions to protect the RFID system s data information. This study investigates important issues related to privacy and security of RF1D based on the recent literature and suggests solutions to cope with the problem.

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A Study on School Uniform Design of High School Girls' Stadents in Gwanju and Mokpo (여고생의 교복디자인 선호에 관한 연구)

  • You Kyung-Sook
    • Journal of the Korean Society of Clothing and Textiles
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    • v.15 no.3 s.39
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    • pp.263-270
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    • 1991
  • The main purpose of this study was to give a right and proper direction in high school girls' uniforms through the comparison of the attitude toward school uniforms and free choice of wearing clothings. The samples were consisted of 319 high school girls' students in Gwanju and Mokpo. The data were analyzed using frequency, percentage and chi-square test. The finding of this study can be summarized as follows: 1. Students prefered to take uniforms than self·control clothes. The greatest reason for the agreement on uniforms is th,It uniforms make sure the identity of the students. The problem in uniform was the disconvenience for activity. 2. Preference for uniform style was semi-fitted double jacket, flat collar blouse, vest and pleated skirt. 3. They make choice of prefering color were green, bluepurple and white, free-choice clothing color were green, light yellow and light blue and uniform color were bluepurple, darkblue and black.

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