• Title/Summary/Keyword: Stability of course

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The Strength Properties of Permeable Hot Mix Asphalt for Surface Course (배수성 아스팔트 표층용 혼합물의 강도특성)

  • Lee, Kwan-Ho;Ham, Sang-Min
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.7
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    • pp.3296-3301
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    • 2011
  • The Porous pavement gains popularity because of several benefits. It is to minimize hydro-planning condition, spraying condition, and splash to increase friction resistance, and decrease noise. Also, other studies showed that it is important to have appropriate porosity to reduce noise and water flush. The purpose of this study is an evaluation on the mechanical properties of asphalt pavements for surface course. In this study the specimen was manufactured using the Gyratory compactor in order to compact the strengthened surface course that involved the two-layer pavement. This study is conducted by using Marshall stability test(KS F 2377), Impact resonance test, Schmidt hammer test(KS F 2730), and the Uniaxial compression test(KS F 2314). Using the Uniaxial compression test and Schmidt hammer test, the values of compressive strength and bearing capacity were measured, and the modulus of elasticity for each specimen was respectively measured using the Uniaxial compression test, Impact Resonance test.

Development of Vehicle Dynamics Control System (차량동역학제어시스템 개발)

  • 김동신;신현성;박병석
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.9
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    • pp.212-219
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    • 1999
  • This paper describes the NANDO VDC (Vehicle Dynamics Control) system for the vehicle stability enhancement and consists of the control strategies , computer simulation and tests on the various road surface. This VDC system controls the dynamic vehicle motion in the emergency situation such as the final oversteer/understeer andallows the vehicle to follow the course as desired by the driver. The system is based on an active yaw control and its performance verified by the test is shown. Also the comparison between the MANDO VDC System and a competitor is carried out.

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Hydrolysis Reaction of Ti Double Alkoxide (Ti Double Alkoxide의 수화반응)

  • ;W.C. LaCourse
    • Journal of the Korean Ceramic Society
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    • v.27 no.5
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    • pp.693-697
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    • 1990
  • TIACA has two different side groups(ligands) as iso-propoxy groups and acetylacetonate groups. These two side groups have different hydrolysis rates. The two different rates of hydrolysis confer unique properties on TIACA, which are stability in aqueous solution and easy preparation of TiO2 and its multi components gels without precipitation. Their hydrolysis rates were monitored with I.R. and U.V. spectrophotometer.

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A New Impression Method Taken Simultaneously for the Complete Dentures (상하악 동시인상에 의한 새로운 총의치 제작법)

  • Cho, Jong-Mahn;Lee, Seong-Goo
    • Journal of the Korean Academy of Esthetic Dentistry
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    • v.9 no.1
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    • pp.20-36
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    • 2000
  • The movements of oral surrounding muscles, lips, and tongue play a very important role while masticating, swallowing, and speaking. In case of the edentulous patient wearing dentures as well, every movement of the tongue can be seen almost the same as that of the dentulous jaw. The crushed food during mastication is swallowed and sent to pharynx. At this course, the contact of the posterior portion of tongue with dentures affects the stabilization of denture. The retention and stability of the complete dentures are related with buccinator muscles of buccal parts, lips in front, and tongue of the lingual sides. Strack(1946) insisted that the arrangement of artificial teeth in the same place as that of the natural dentition is the best way to maintain the stability of denture. In this report, I would like to introduce the several advantages of a new impression method taken simultaneously, and its procedures and clinical cases.

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A Study of Joint Therapy (관절치료에 관한 연구)

  • Bae, Sung-Soo;Lee, Myung-Hee;Lee, Sang-Yeul;Yoon, Chang-G.
    • Journal of the Korean Society of Physical Medicine
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    • v.3 no.2
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    • pp.121-125
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    • 2008
  • Purpose : The objective of this study was conducted to find out the treatment of joint problems. Methods : This is a literature study with books, seminar note and international course books. Results : Passive oscillation and distraction movement therapy is only joint mobilization and pain control. In the joint therapy need muscle strengthening, training of eccentrical control and neurophysiological therapy for joint mobility, stability, stability of mobility and skill. Conclusion : Joint therapy is not only joint mobility but also strengthening of soft tissue. Need the neurophysiological therapy those are use of ventromedial motor nucleus and dorsolateral motor nucleus, reciprocal inhibition, eccentrical muscle contraction training, proprioceptors and exteroceptor for structures and functional activities. For the pain control, reduce swelling, keeping GAGs and functional activities need direct and indirect therapy.

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A Study on Course Stability of Towing and Towed Vessels System under Wind Pressure (풍압력하에서의 예선ㆍ피예선계의 침로안정성에 관한 연구)

  • 손경호;김용기
    • Journal of the Korean Institute of Navigation
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    • v.24 no.3
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    • pp.113-122
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    • 2000
  • 본 논문에서는 손상선박의 안전대책에 관한 연구의 일환으로서, 황천항행중인 선박이 충돌, 좌초 등 원인에 의해 조종불능이 되었을 때를 가상하고, 예선ㆍ피예선계의 침로안정성에 미치는 풍향, 풍속, 예항삭의 길이의 영향을 이론적으로 검토하고, 풍압하에서 피예선을 다른 안전한 장소로의 예항에 대하여 하나의 지침을 주는 것을 목적으로 한다. 여기에서 실선은 Hulk carrier와 Passenger liner를 모델로 삼았고 외력으로서는 파도가 충분히 발달되지 않은 바람이 부는 초기상태 혹은 저속으로 항행하는 상태를 고려하여 바람의 영향만을 취급하며 피예선은 조타를 하지 아니한다.

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Effect of Resin Finishing on the Physical Properties of the Knitted Fabrics (수지처리가 환편 니트 소재의 물성에 미치는 영향)

  • Kwon Young-Ah;Park Jong-Sik
    • Textile Coloration and Finishing
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    • v.18 no.3 s.88
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    • pp.23-30
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    • 2006
  • The bending properties, wrinkle resistance, and fabric retention behaviors of cotton knitted fabrics in the wale and course directions were studied for their dependence upon resin finishing, knit structure, and washing cycles. Stiffness, wrinkle recovery angles, and dimensional stability were investigated before and after resin finishing and laundering. It has been found that any change in the physical properties of the knitted fabrics with respect to knit structure and fabric directions are related to accompanying modifications to the state of the fiber properties. The decrease of fabric shrinkage rates and wrinkle recovery properties from increasing laundering cycles is related with resin incorporated on the fiber surface. This study shows that resin finishing on knitted fabrics can be performed only to improve fabric retention properties with reduced wrinkle recovery properties.

The Safe Manoeuvring of a Ship in Following and Quartering Seas

  • 고옥덕
    • Journal of the Korean Institute of Navigation
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    • v.23 no.2
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    • pp.23-27
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    • 1999
  • When a ship is running in following and quartering seas and on a crest with the ship′s length being nearly the same as the wave length, ship′s stability will be lost most; "T" shape crests with highly concentrated energy will appear during the process of transformation from irregular waves to regular ones, and the ship may be under continuous impact of large waves for a long period of time; Synchronism will also appear when the ship′s natural period of rolling and period of encounter are close to each other. For safe navigation, proper stability should be well ensured, proper speed and course chosen with speed under 1.8L1/2 kn (L is the ship′s length), initial listing avoided, special attention paid to steering.

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Beam stability improvement of a liquid metal ion source (액체 금속 이온원의 빔 안정도 향상)

  • 현정우;임연찬;김성수;박철우;이종항;강승언
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2004.04a
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    • pp.504-507
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    • 2004
  • Previous studies on the liquid Gallium ion sources used an electro-chemically etched tungsten wire with a coil-type heater. Such a structure requires excessive power consumption in the course of heating the liquid metal. In this work, a new structure is proposed that replaces the coil-type heater. It uses a Gallium reservoir made of six pre-etched 250 $\mu\textrm{m}$ tungsten wires that surround the needle electrode. Gallium loading at the reservoir is observed to be much more stable, resulting in an improved beam stability.

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A Study about the Pitch Stability of Exploratory Underwater Vehicles (해저탐사잠수정의 연직평면에서의 방향안정성에 관한 연구)

  • 윤점동
    • Journal of the Korean Institute of Navigation
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    • v.11 no.1
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    • pp.93-106
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    • 1987
  • Nowadays natural resources on shore have been almost exhausted all over the world and mankind is beginning searching for unexploited resources on the bed of deep-sea floor. In exploring mineral resources and etc. in the ground of sea-bed, a sumbersible craft is one of the most important tools. These days, the stage of the technique of building and operating an exploring submersible craft is almost alike that of building and operating an airplane in the first years of the nineteen-twenties. At the present time, the problems arising in building and operating a submersible craft can be divided into four parts as follows; 1. How to build a hull that can bear high pressure under deep sea level. 2. How to decide the necessary facilities to be put on it. 3. How to decide the scope of stabilities and maneuvering characteristics of it. 4. On what sea conditions, the devices of launching and recovering it should be designed on the mother-ship. In this paper treating one of the third problems the author made a mathematic formula that can be useful in deciding the scope of dynamic course stability on the vertical plane and actually calculated the onset speed of pitch instability of an exploring craft. With the above mentioned calculations the author demonstrated that the value of $Z_g$ and the speed of a submerged craft are the most important factors in decideing the scope of dynamic stability on the vertical plane.

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