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A Study on the Mechanical Mechanism According to the Groove Shape of T-welded Joint (T-joint 용접부의 형상에 따른 역학적 메카니즘에 관한 연구)

  • 방한서;김종명
    • Journal of Welding and Joining
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    • v.17 no.6
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    • pp.53-61
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    • 1999
  • The use of thick plate in increasing in recent years due to the rapid expansion of chemical plants, nuclear plants, ships and other industrial plants. Welding is the most popular joining techniques employed in manufacturing industrial machineries and structures. Normally, Groove shapes are prepared according to appropriate rules and regulations such as KS, JIS, AWS, LR, DNV and etc. for various thicknesses of plate. However those groove angles tend to be too large. As a result of large groove angle, residual stress, deformation of material and strength reduction is obtained. Therefore, the reliability and safety of structures and machinery tend to be decreasing. Therefore, in this paper, theoretical as well as experimental study are carried out to find optimum groove shapes for T-welded joint of mild steel. The test specimen are made in same condition with simulation model. Welding residual stresses measurement by sectional cutting method. ⅰ) The mechanical difference for change the thickness of plate and groove angle are not appeared. ⅱ) In a mechanical point of view minimum preparation angle(40°) is more suitable than maximum groove angle(60℃). ⅲ) The measurement value and distribution of welding residual stresses are not effected largely by groove angle. It is mechanical restraint that mainly affect welding residual stresses distribution. In mechanical point of view minimum groove angle is more suitable than maximum groove angle. Therefore, it is appropriate to minimize the size of groove shape in strength and safety.

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Voltage Clamped Tapped-Inductor Boost Converter with High Voltage Conversion Ratio (고승압비를 갖는 전압 클램프 탭인덕터 부스트 컨버터)

  • Kang, Jung-Min;Lee, Sang-Hyun;Hong, Sung-Soo;Han, Sang-Kyoo
    • The Transactions of the Korean Institute of Power Electronics
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    • v.17 no.1
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    • pp.34-40
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    • 2012
  • In this paper, voltage clamped tapped-inductor boost converter with high voltage conversion ratio is proposed. The conventional tapped-inductor boost converter has a serious drawback such as high voltage stresses across all power semiconductors due to the high resonant voltage caused by the leakage inductor of tapped inductor. Therefore, the dissipative snubber is essential for absorbing this resonant voltage, which could degrade the overall power conversion efficiency. To overcome these drawbacks, the proposed converter employs a voltage clamping capacitor instead of the dissipative snubber. Therefore, the voltage stresses of all power semiconductors are not only clamped as the output voltage but the power conversion efficiency can also be considerably improved. Moreover, since the energy stored in the clamp capacitor is transferred to the output side together with the input energy, the proposed converter can achieve the higher voltage conversion ratio than the conventional tapped-inductor boost converter. Therefore, the proposed converter is expected to be well suited to various applications demanding the high efficiency and high voltage conversion ratio. To confirm the validity of the proposed circuit, the theoretical analysis and experimental results of the proposed converter are presented.

Foods and Drugs Classified by Constitution (체질별(體質別) 식품(食品)과 약(藥))

  • Wang, Myoung-Ja
    • Journal of East-West Nursing Research
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    • v.2 no.1
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    • pp.62-82
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    • 1997
  • If we eat long time foods that don't suit our constitution, health is broken and we take a disease. Therefore, care of foods and taking medicine by constitutional notion have a object that is normal control of constitution. It is attained when we maintain an adequate balance of Jang and Bu(臟腑) organs functional deflection. Theory of SaSang constitution by Lee-Jae Ma provides us a proper base of theory. But, later foods and drugs classified by constitution, that is suggestied by many scholars, is some different. Therefore, it is doubtful whether choice of foods and drugs suitable to constitution is right. If we use foods and drugs suitable to constitution exactly, we can decrease a side effect arisen from unsuitableness. On this, I study by literatures in order to provide foundational data. Lee-Jae Ma classified four species constitution, I compared twelve literatures by constitution, classified profit and harmful foods, and arranged and classify drugs that literature writer suggests in common. On base of this study, I suggest that foods and drugs classified by constitution is as follows. 1. Lee-Jae Ma made SaSang constitution medicine, but didn't suggestied use of foods, therefore, commoness of foods constitutional classification must be arranged. 2. Also commoness of drugs constitutional classification must be arranged. 3. Other literatures must be compared and analyzed except those of this study, because I didn't analyze many SaSang literatures.

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The Effect of Professor's Individualized Consideration on the Personal Growth of Chinese Students Study Abroad in Korea: The Moderating Effect of Perceived School Support

  • Hahm, SangWoo;Sun, SiYao
    • International Journal of Advanced Culture Technology
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    • v.8 no.2
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    • pp.76-84
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    • 2020
  • In general, members of an organization want their own growth and development. As these members grow or develop, they feel satisfied and fulfilled in the process. Growth or development can motivate members to become more involved in their jobs. Therefore, these concepts are very important for organizations as well as individual members. Various elements of the organization affect the growth of its members. Leaders influence members to achieve organizational goals. Leaders can therefore be an important variable influencing the growth of members. Specific leadership informally develops the potential to identify and satisfy members' personal needs and to achieve higher performance. These leader behaviors motivate members and drive their growth. Thus, this leadership will have a significant impact on the growth of members. In addition, in this relationship, if members have perceived organizational support, they can further improve their expectations for growth. Therefore, support from leaders and organizations will have a positive impact on employee growth. This study highlights the importance of the growth of members of the organization. It demonstrates the moderating effects of leader's individualized consideration and perceived organizational support necessary elements for member growth. Through this process, the purpose and significance of the study are to identify the variables that affect the personal growth of members and explain how they can grow.

The cause and prevention for dust accident and necessity of safety device (분진사고의 원인 및 대응방안과 안전장치의 필요성)

  • Oh, Sun-Il;Joo, Yong-Ma;Kim, Bu-Yeol;Kang, Kyung-Sik
    • Journal of the Korea Safety Management & Science
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    • v.13 no.2
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    • pp.77-82
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    • 2011
  • In the industrial site of 21st century, there are many and various powders of material, product and fuel of coal, chemical, detergent, paint, feed and more. Therefore, there always is a possible danger of dust explosion in each and every procedure and actually, there are increasing frequency of dust explosion as the use of dust and its amount increases in processes. Therefore, if we leave the current status like now, the unexpected massive dust explosion and its risk cannot be effectively prevented so there has to be effective application of understanding and development of explosion-prevention technology about dust explosion. Therefore, this research set the limit of research to systematically arrange the research results about dust explosion phenomenon and its prevention up to date and has its purpose to theoretically establish the prevention technology about dust explosion based on these theories.

A Study on the Symbolism of the Eastern-Western Costumes' Color in Films (영화에서 나타난 동.서양 의복색의 상징성에 관한 연구)

  • Paik, Sun-Young
    • Journal of the Korean Society of Fashion and Beauty
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    • v.3 no.2 s.2
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    • pp.25-30
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    • 2005
  • This study is to research the symbolism of the Eastern and Western costumes' color in films. Therefore, I chose movies about colors, which are 'Trzy Kolory', a Western movie directed by Krzysztof Kieslowski and 'Hero', an Eastern movie directed by Zhang Yimou. The purpose of this study is to figure out the symbolism of the common colors shown in both movie which are red, blue and white. Also, by comparing the eastern and western color symbols I studied the ambivalence of colors. Therefore, the comparison of the eastern and western color symbolisms are as the followings. The color red symbols charity in the movie and jealous, hatless, lies, expansion, self esteem, resist, struggle and sadness in the movie . The color blue symbols freedom, lost, gloomy and sadness in the movie and sacrifice and sadness in the movie . The color white symbols equality and emptiness in the movie and true love, sadness and sacrificed love in the movie . Consequently, it appears that the colors symbolize differently in the East and the West. Three series of which is the West movie has more positive meanings than the Eastern movie. Therefore, the meanings of symbols of the costumes' color are different in the East and West as they have different cultures, and also they could be expressed differently by the directors intention.

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The Influence of Tsunamis on Moored Ships and Ports

  • Kubo Masayoshi;Cho Ik-Soon;Sakakibara Shigeki;Kobayashi Eiichi;Koshimura Syunichi
    • Journal of Navigation and Port Research
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    • v.29 no.4
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    • pp.319-325
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    • 2005
  • Planning for the construction of ports and harbors usually takes place without the consideration of tsunamis because of their rare occurrence, approximately once every 100 years. However, recent warnings indicate that massive earthquakes could occur in Japan within the next 30 years. Earthquakes may generate large-scale tsunamis. Therefore, any tsunamis in the vicinity of Japan would also be expected to affect eastern Korea. Therefore, with the looming concerns of tsunamis and earthquakes, immediate attention must be given to the planning of ports and harbors. The warnings deserve an immediate response. The threatened regions cover a very large territory, and the degree of severity of the tsunamis is forecasted to be varied. Therefore, any modeling of the potential scenarios will require a broad array of possibilities. The objective of this paper is to consider the potential damage from tsunamis to ports and moored ships in Japan and Korea. In addition, consideration will be given to how the construction plans of ports and harbors should be changed to cope with the threats from earthquakes and tsunamis.

A Effect of Shot Peening for Fatigue Life of Spring Steel for Vessel Application (선박용 스프링강의 피로수명에 미치는 쇼트피닝의 영향)

  • Ryu Hyung-Ju;Park Keyung-Dong
    • Journal of Advanced Marine Engineering and Technology
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    • v.29 no.4
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    • pp.426-435
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    • 2005
  • The lightness of components required in automobile and machinery industries is requiring high strength of components. Therefore this requirement is accomplished as the process of shot-peening method that the compressive residual stress is made on the metal surface as one of various improvement methods. Special research is, therefore, needed about compressive residual stress on the metal surface in the process of shot-peening method. Therefore, in this paper the effect of compressive residual stress of spring steel(JISG SUP-9) by shot-peening on fatigue crack growth characteristics in environmental condition(temperature) and mechanical condition(shot velocity, stress ratio) was investigated with considering fracture mechanics. By using the methods mentioned above, the following conclusions have been drawn. (1) The fatigue crack growth rate(da/dN) of the shot-peened material was lower than that of the un-peened one. In high temperature range. fatigue crack growth rate decreased with increasing temperature range, while fatigue crack growth rate increased by decreasing temperature in low temperature. (2) Fatigue life shows more improvement in the shot-peened material than in the un-peened material. And compressive residual stress of surface on the shot-peen processed operate resistance force of fatigue crack propagation.

High Speed and High Precision Control of Linear Voice Coil Motor for Optical Disc (광 저장장치용 리니어 보이스 코일 모터의 고속, 고정밀 위치제어)

  • Kim, Se-Woong;Jun, Hong-Gul;Park, No-Chul;Yang, Hyun-Seok;Park, Young-Pil
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.11a
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    • pp.754-758
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    • 2000
  • In recent years, the LDM(Linear DC Motor) is widely used, because it has more merits than other rotary motors. First, if system requires linear motion, LDM realizes direct linear motion as rotary motor does not. Second, system is simple and easy to control, and so on. In optical disc drive, a tracking system consists of two parts. One is fine actuating and the other is coarse actuating. For coarse actuating VCM(Voice Coil Motor) actuator is used as a basic drive mechanism. In this paper, MC(Moving Coil) type LDM is designed, manufactured and controlled. System is composed of mechanical-electromagnetic component, therefore mechanical loss and electromagnetic loss exist. The dominent mechanical loss is friction which results from sliding between guide shaft and hole. Therefore, this paper shows the friction compensation control. High speed and accurate position is not gained only PID control, therefore other control method is applied to the system.

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On English Non-DP Subjects and their Structural Position (영어 non-DP 주어의 구조적 위치)

  • 홍성심
    • Language and Information
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    • v.6 no.2
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    • pp.1-14
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    • 2002
  • This paper discusses so called the non-DP subject constructions in English. In general, a subject is a DP that bears Nominative case and that occupies 〔Spec, IP〕. However, in some examples under investigation, it looks as if non-DP categories such as Prepositional Phrases(PP), Adjectival Phrases(AP), Adverbial Phrases (AdvP), Small Clauses (PreP or SC), and VP occupy the canonical subject position, 〔Spec, IP〕. Under the framework of Chomsky's (1993, 1995) along with his previous works (Chomsky 1981, 1986), the Case Checking mechanism undoubtedly assumes that only DPs can have Case Therefore, the Case Checking/Agree mechanism is stated such that the strong uninterpretable feature, in this case Case feature (D or NP) feature must be checked off in a certain manner. Therefore, any phrasal categories other than DPs are not included in the considerations. Nonetheless, there are many instances of non-DP categories in English that occupy the seemingly canonical subject position, 〔spec, IP〕. In this paper, it is proposed that the actual position of these non-DP subjects in English is not in Spec of IP. Rather, they occupy 〔Spec, TopP〕 under CP in the sense of Lasnik & Stowell (1991), Rizzi (1997), and Haegeman & Gueron (1999). In its effect, therefore, this paper extends the idea of Stowell (1981) who argues that the clausal subjects in English is not in 〔Spec, IP〕, but in 〔Spec, TopP〕. We further argue that Stowell's version of Case Resistance Principle must be extended in order to accomodate many more occurrences of so called non-DP subjects.

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