• Title/Summary/Keyword: pivot

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Effect of Friction on the Hysteresis of the Thrust Forces Acting on Auto Leveling Devices in Vehicle Head Lamps (헤드 램프 빛의 각도 자동 조절 장치에 작용하는 추력의 히스테리시스에 대한 마찰의 영향)

  • Baek, Hong;Kim, Jae-Hoon;Nam, Jin-Sik;Park, Sang-Shin
    • Tribology and Lubricants
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    • v.35 no.6
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    • pp.369-375
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    • 2019
  • This paper presents a new method on how to calculate the thrust forces acting on an auto-leveling device in headlamps for passenger vehicles. The leveling device is used to lower the angle of lights when a load in the trunk of the vehicle lifts it. In the process of the headlamp design, it is imperative to predict the external forces so that the designers can decide whether to proceed or not. The device is composed of three pivot joints with no reaction moment, a plate that holds the lamp, and a leveling motor that changes rotation to linear motion. In this study, force balance, moment balance, and geometric compatibility are applied to the leveling device system so that a nonlinear system of equations can be derived; the multi-dimensional Newton-Raphson algorithm is then used to solve these. A sensitivity analysis is carried out to verify which design variables affect the system the most: the mass of the lamp and the height between the pivot and leveling device affect the thrust forces the most. Then, considering the friction forces between the moving parts, the hysteresis of the forces are derived. An experimental apparatus, designed and developed in this study, is used to verify the exactness of the derived equations. The results from experiments coincide well with the calculated results. The friction hysteresis, in particular, proves this upon analysis.

Transient Calcification of Autogenous Grafted Patellar Tendon in Anterior Cruciate Ligament Reconstruction - A Case Report - (슬관절 전방 십자 인대 재건술 후 발생한 이식 건의 일과성 석회화 - 증례 보고 -)

  • Chung, Hyun Kee;Choi, Choong Hyeok;Kim, Jong Heon;Kim, Jae Young
    • Journal of the Korean Arthroscopy Society
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    • v.3 no.1
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    • pp.30-34
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    • 1999
  • We report the case of a 30-year-old man who was presented with transient calcification on the graft shortly after anterior cruciate ligament(ACL) reconstruction using a autogenous bone patellar tendon. The patient underwent ACL reconstruction with two incisional technique and six month later, calcific density was seen radiologically around the graft. On postoperative 13 months follow-up radiographic films, the calcific density disappeared. After two months of operation, Lachman and pivot shift test were negative and one millimeter side to side difference was detected in KT-1000 with 20 Ibs strength. But 6 months after the reconstruction, mild anterior instability was detected with the calcific density around the grafted tendon. However the anterior stability was recovered according to the disappearance of calcific density.

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A Study on Exporting Small & Medium Enterprises Based on Accident Types of Derivatives Transactions: Focus on Exporting Small & Medium-Sized Enterprises with KIKO Currency Option (파생상품의 투자 리스크 요인 분석을 통한 중소수출 기업의 환리스크 관리 방안 - KIKO를 통해 살펴본 국내 중소제조업체를 중심으로 -)

  • Cho, Young-Hun
    • Journal of Arbitration Studies
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    • v.26 no.1
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    • pp.89-105
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    • 2016
  • 2008 began with the American financial crisis which gave way to the liquidity crisis (Fannie Mae and Freddie Mac) situation in which 'the withdrawal of investment initiated from the insufficiency of the U.S. subprime mortgage loan companies', 'the large size loss situation of the financial company (Bear Stearns) due to the American structured bond insufficiency' and the second half opening part national debt mortgage company. Within the American financial crisis was propagated the crisis of international derivatives. Due to this, the withdrawal of foreign investment progressed in the interior of a country with the considerable. By the end of 2007, the exchange rate fluctuation was absorbed in the domestic financial circle on the belief the potentiality of the domestic financial market had been growing drastically through the expansion of the foreign currency debt according to this and it came to the defence but while the exchange rate jumped up to the dollar shortage according to the international crisis, the small and medium companies making the banks and exchange rate-related derivatives contract were going bankrupt due to the derivatives loss. The small and medium factories establish the bank exchange rate-related derivatives has nose (KIKO), pivot (PIVOT), and snowball (Snowball) etc. at that time and the damage which it is the KIKO grasped at 6 end of the months in 2008 caused by reaches to 1 thousand billion 4 thousand hundred million dollars. Small and medium companies in which the dollar which it has to denounce among small and medium companies bearing the KIKO contract in fact with the Knock-In generation city bank exceeds the amount of sales were known to be 68 enterprises among 480 enterprises. This paper departs in this awareness of a problem and tries to look into the risk factor of the derivatives, including nose and study the essential ring risk management plan of small and medium manufacturer.

Study on Improving Oriental Medicine Statistical System for Multidimensional Statistical Data

  • Yea, Sang-Jun;Kim, Chul;Kim, Jin-Hyun;Jang, Hyun-Chul;Kim, Sang-Kyun;Song, Mi-Young
    • International Journal of Contents
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    • v.7 no.3
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    • pp.13-18
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    • 2011
  • Oriental medicine statistics are essential in research planning, research evaluation, and policy decision based on objective data. However, integrated administration of such statistics is not presently possible in the oriental medicine field, which has been slow in incorporating information communication technology. In an effort to address this problem, the Korea Institute of Oriental Medicine (KIOM) developed an oriental medicine statistical system in 2009, and the system has been offered in the traditional medicine information portal of OASIS. However, according to a 2010 survey targeting OASIS users, those surveys reported that needs for a system where various statistical data can be extracted via an interactive approach to multidimensional data. As a result of an analysis of the functions of the existing system, it was found that it is necessary to array and arithmetically analyze Stats Value, Drill Up & Drill Down, and Pivot. To this end, the existing DB schema should be redesigned. Based on our analysis result, we redesigned the database into a structure that is applicable to the reverse pivot algorithm. We used J2EE/JSP and a Flex framework to design and develop an oriental medicine statistical system that can provide multidimensional statistical data. Considering that the improved oriental medicine statistical system is planned to be offered by OASIS of KIOM, utilization and value of oriental medicine statistical data are expected to be enhanced.

Rigidfix 와 Infrafix 로 고정한 슬괵건을 이용한 전방 십자인대 재건술 후 경골터널의 확장

  • Choi, Nam-Hong;Jung, Yoo-Hoon
    • 대한관절경학회:학술대회논문집
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    • 2009.10a
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    • pp.153-153
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    • 2009
  • The purpose of this study was to evaluate tibial tunnel widening prospectively after anterior cruciate ligament (ACL) reconstruction with hamstring tendon grafts using Rigidfix (DePuy Mitek, Raynham, MA) femoral fixation and Intrafix (DePuy Mitek) tibial fixation. 56 consecutive patients who underwent ACL reconstruction with a minimum of 2 years' postoperative evaluation were reviewed. On the anterior-posterior (AP) and lateral radiographs, the diameter of the tibial tunnel was measured at proximal, middle, and distal positions and the shape of the tibial tunnels were classified. Tunnel widening was defined as widening of greater than 2 mm. Group I was defined as cases with no tunnel widening and group II defined as cases with tunnel widening. Postoperative laxity evaluations were performed using Lachman test, pivot-shift test, and Instrumented laxity testing using the KT-1000 arthrometer. On the AP radiographs, the average diameter of the tibial tunnel increased 8.8% at 6 months and 8.5% at 12 months postoperatively compared to the immediate postoperative day. On the lateral radiographs, the average diameter of the tibial tunnel increased 7.2% at 6 months and 8.1% at 12 months year postoperatively compared to the immediate postoperative day. The tunnel shape evaluation revealed predominantly linear type in 53 patients (95%). Group I was 42 patients (75%) and group II was 14 (25%). The average KT-1000 measurement was 1.0~1.8 mm in group I and 2.1~2.8 mm in group II (p>0.05) The Lachman and pivot-shift showed tests no significant differences between the two groups. In conclusion, hamstring ACL reconstruction using Rigidfix and Intrafix fixation showed less widening of the tibial tunnels than observed in previously published studies.

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The Analysis of Apparel CAD System regarding Tuck and Pleats Manipulation Function in Basic Patterns (기본원형을 이용한 Tuck, Pleats Manipulation 기능에 관한 어패럴 CAD 시스템 분석)

  • Kwon, Sook-Hee;Hong, Seon-Cheol;Jeon, Eun-Kyung
    • Korean Journal of Human Ecology
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    • v.15 no.3
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    • pp.457-467
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    • 2006
  • The following research compares two mostly-used apparel systems that are used in colleges of Korea, Gerber and PAD, by analyzing advantages and disadvantages of their Dart, Tuck and Pleats-related functions in pattern construction process. The results are the following: First, regarding transformation methods, Gerber system was able to use pivot method, while PAD system was able to use both pivot and slash method. As for movement, distribution, synthesis, folding, producing additional Dart function, the PAD system was not able to synthesize more than two Darts, and only showed differences for other functions. On the other hand, the diamond-shape Dart and diagonal Dart can be produced only in PAD system, while none of curvy shaped Dart can be produced in both systems. Second, as for pattern outer line connection capability, which is a Dart automatic transformation function, both systems showed unnatural shapes and need for correction. Third, when constructing according to the type of Tuck, we could distribute multiple Darts at a time with PAD system, while with Gerber system, distribution into multiple Darts at a time was impossible at all. Fourth, when constructing according to the contour of Pleats, Gerber system made it possible to make construction of multiple lines and box/inverted Pleats with just one order, but PAD system required repetitive tasks, which remains room for enhancement in regard to such inefficiency.

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Free and Forced Vibration Analysis of a Hard Disk Drive Considering the Flexibility of Spinning Disk-Spindle, Actuator and Supporting Structure (회전 디스크-스핀들, 액츄에이터와 지지구조의 유연성을 고려한 하드 디스크 드라이브의 고유 및 강제 진동 해석)

  • Seo, Chan-Hee;Jang, Gun-Hee;Lee, Ho-Seong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.05a
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    • pp.660-665
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    • 2006
  • This paper presents a finite element method to analyze the free and forced vibration of a hard disk drive (HDD) considering the flexibility of a spinning disk-spindle with fluid dynamic bearings (FDBs), an actuator with pivot bearings, an air bearing between head-disk interface and the base with complicated geometry. Finite element equation of each component is consistently derived with the satisfaction of the geometric compatibility of the internal boundary between each component. The spinning disk, hub and FDBs are modeled by annular sector elements, beam elements and stiffness and damping elements, respectively. The actuator am, E-block, suspension and base plate are modeled by tetrahedral elements. The pivot bearing in the actuator and the air bearing between head-disk interfaces are modeled by the stiffness element with five degrees of freedom and the axial stiffness, respectively. A global matrix equation obtained by assembling the finite element equations of each substructure is transformed to a state-space matrix-vector equation, and both damped natural frequencies and modal damping ratios are calculated by solving the associated eigenvalue problem with the restarted Arnoldi iteration method. Modal and shock testing are performed to show that the proposed method well predicts the vibration characteristics of a HDD.

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Ancient Chinese Astronomical Analysis of the Chapter, Wigi Haeng in Youngchu (Spiritual Pivot) (영추, 위기행편에 대한 중국 고천문학적 분석)

  • Ur, Woosen
    • Korean Journal of Acupuncture
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    • v.36 no.4
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    • pp.252-263
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    • 2019
  • Objectives : This research aimed to 1) analyze the true meanings of the chapter, 'Wigi Haeng (Wei Qi Xing), the movement of guard qi' in Youngchu (Ling Shu) from the point of view of ancient Chinese Astronomy, 2) calculate the speed of Wigi over 24 Chinese seasons, 3) analyze the true meaning of daytime and nighttime in the chapter. Methods : 1) The chapter 'Wigi Haeng' was analyzed using concepts of ancient Chinese astronomy, 2) the records of angular distances of 28 constellations in the Book of Han (Han Shu) were used to analyze the meanings, and 3) the records of lengths of daytime and nighttime in the Book of Hou Han (Hou Han Shu) were used to calculate the speed of Wigi. Results : 1) The author of the chapter 'Wigi Haeng' did not consider the irregularity in the angular distances of the 28 Chinese constellations (Su). 2) The commentary in the Huangjenaegyong Taeso (Huang Di Nei Jing Tai Su) about the constellations in the chapter is correct. 3) The speed of Wigi changes in daytime and nighttime depending on the seasons. 4) When the speed of Wigi increases in daytime, the speed in nighttime decreases, and vice versa. 5) The beginning of daytime in 'Wigi Haeng' is not the time of sunrise but the time of dawn (2.5 Gak before sunrise). The nighttime ends 2.5 Gak after sunset. Conclusions : 1) The chapter 'Wigi Haeng' demonstrates the ancient astronomical point of view on the universe and the movement of Wigi. The speed of Wigi is variable. 2) This chapter does not address the irregularity in the angular distances of the 28 Su. 3) More research is needed on the meaning of daytime and nighttime in 'Wigi Haeng'.

A Study on the Optimal Forebody Forms for Minimum Wave Resistance (최소조파 저항성능을 갖는 최적 선수형상에 관한 연구)

  • Sung-Eun Kim
    • Journal of the Society of Naval Architects of Korea
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    • v.28 no.2
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    • pp.28-39
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    • 1991
  • A study on the optimization problems to find forebode shapes with minimum wavemaking and frictional resistance was performed. The afterbody was fixed as a given hull and only forebode offsets were treated as design variables. Design variables were divided into the offsets of given hull and small variation from them. For the wavemaking resistance calculation, Neumann-Kelvin theory was applied to the given hull and thin ship theory was applied to the small variation. ITTC 1957 model-ship correlation line was used for the calculation of frictional resistance. Hull surface was represented mathmatically using shape function. As object function, such as wavemaking and frictional rersistance, was quadratic form of offsets and constraints linear, quadratic programing problem could be constructed. The complementary pivot method was used to find the soulution of the quadratic programing problem. Calculations were perfomed for the Series 60 $C_{B}$=0.6. at Fn=0.289. A realistic hull form could be obtained by using proper constraints. From the results of calculation for the Series 60 $C_{B}$=0.6, it was concluded that present method gave optimal shape of bulbous bow showing a slight improvement in the wave resistance performance at design speed Fn=0.289 compared with the results from the ship theory only.

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A Study on Tang Zong-hai's Theory of Qi Transformation within the Six Meridians - focussed on 『Shanghanlun Qianzhubuzheng』 - (당종해(唐宗海)의 육경(六經) 기화학설(氣化學說)에 대한 연구(硏究) - 『상한론천주보정(傷寒論淺注補正)』을 중심으로 -)

  • Lee, Sang-hyup
    • Journal of Korean Medical classics
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    • v.32 no.4
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    • pp.67-90
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    • 2019
  • Objectives : This study aims to summarize Tang Zong-hai's Qi transformation theory of the Six meridians through his book "Shanghanlun Qianzhubuzheng傷寒論淺注補正" where he integrated Western anatomy with the Qi transformation theory of East Asian Medicine to interpret Zhang Zhong Jing's "Shanghanlun(傷寒論)". The objective is to assist clinical application. Methods : Focusing on the contents of disease of the six meridians in the "傷寒論淺注補正", Tang's theories on the function of Zangfu(臟腑), Opening-Closing-Pivot(關闔樞), Inter-communication of Zangfu(臟腑相通), the Twelve Meridians(十二經脈) from his other publication "中西匯通醫經精義" were examined and related to in the process of explaining Qi transformation theory in detail. Results : 1. The Qi transformation function of the Taiyang meridian is related to "膀胱者, 氣化則能出" where the Small Intestine and Bladder inter-communicate. 2. The Qi transformation function of the Yangming meridian is related to the control of dryness and dampness through the Qi transformation of "陽明不從標本, 從乎中." 3. The Qi transformation function of the Shaoyang meridian is related to the Life-Fire function of the Triple Energizer-Gallbladder-Pericardium coalition through "少陽屬腎." 4. The Qi transformation function of the Taiyang meridian refers to the Heart Fire nurturing the Spleen Earth by creating 膏油 through veins. 5. The Qi transformation function of the Shaoyin meridian is related to the controlling of the Nutrient Qi(營氣) and Defense Qi(衛氣) through '心主血脈, 腎主元氣.' 6. The Qi transformation function of the Jueyin meridian is related to the ability of 和風 which results from '陰盡陽生' to harmonize and control the balance of Water Coldness(水冷) and Fire Heat(火熱). Conclusions : Tang's Qi Transformation Theory of the Six Meridians is his key theory explained from the perspective of Qi transformation of disease in the six meridians of "Shanghanlun", closely related to basic theories such as theory of Zang form(臟象學說), Opening-Closing-Pivot(關闔樞), Inter-communication of Zangfu(臟腑相通), the Twelve Meridians(十二經脈) of East Asian Medicine.