• Title/Summary/Keyword: Turning Characteristics

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A Study on the Drafting Method According to the Somatotype (평면재단과 입체재단 비교를 통한 체형별 원형 연구)

  • Lee Jeong Yim
    • Journal of the Korean Society of Clothing and Textiles
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    • v.15 no.3 s.39
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    • pp.309-320
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    • 1991
  • The purpose of this study was to develope a pattern drafting method for various somatotype which contribute largely to increase the fitness and comfort of garments. This study had 8 subjects who were college girls who had prominent somatic characteristics. The study was carried out by the following procedures. 1. The 8 subjects who had prominent somatic characteristics were cheesed by photograph- ing. The somatotypes of 8 subjects were classified into Standard somatotype, Turning over somatotype, Bending somatotype and Turning over-Bending somatotype. 2. Under the criterion of the body surface development, the comparative investigation on the pattern and the sensory evaluation were accomplished in the flat pattern method and the draping pattern method. 3. The body surface development of them were made by the draping pattern method. 4. In the result of the comparative investigation and the sensory evaluation, it was found that the flat pattern had better appearance and comfort than the draping pattern, and the draping pattern included more somatic characteristics than the flat pattern. 5. On the basis of those result, the pattern drafting method according to the somatotype was indicated and it was examinated by the clothing experiment. 6. The sensory evaluation for appearance and comfort was applied to evaluate the new basic pattern for four somatotype by comparing it with the conventional basic pattern (Rim, won ja' 5). The result of the sensory evaluation, it was found that the new basic pattern was more suitable for each somatotype than the conventional basic pattern.

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Turning Characteristics of differential materials (이종 금속의 선삭 가공 특성에 관한 연구)

    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.7 no.3
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    • pp.43-50
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    • 1998
  • In the use of CNC machine tool, the unmanned production system has been growing in the manufacturing field. Thus, it is necessary to monitor adequate tool fracture during the cutting process efficiently. This experimental study is intended to investigate the development of flank wear in sysnchronous turning of differential materials(Aℓ/GC) which is used in industrial application and it is acknowledged as a machine to difficult material. In cutting process change of velocity, change of feed, and change of depth of cut were investigated on the effect of flank wear, and slenderness ratio is also investigated. The conclusions of this paper are summarized as follows; 1.Under the high cutting speed condition, the flank wear is affected by the feed and depth of cut. but the influence of feed on the flank wear is larger than the depth of cut and that is reduced when the velocity is low. 2.Under the high cutting speed, as the smaller slenderness ratio is, the shorter tool life is under the lower cutting speed, the effect of slenderness ratio on the flank wear is low. 3.Using the characteristics of cutting force, the flank wear of a tool can be detected 4. Investigating the development of flank wear, there are almost no differences between the characteristics of cutting force and feed force. Finally, these data from the differntial materials cutting process will be used in the basic field of precision and economic cutting process.

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Study on the Difference of the Maneuvering Characteristics of a VLCC in Standstill from those of her in Running

  • Lee, Chun-Ki
    • Journal of Navigation and Port Research
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    • v.33 no.9
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    • pp.623-628
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    • 2009
  • The objective of this paper is to make clear the difference of maneuvering characteristics of a VLCC in standstill from those of her in running. The authors made mathematic models to calculate maneuvering motions of a VLCC in standstill using various ahead engine with full rudder angle and calculated their motions in each case and compared the calculated values with those of the same vessel running in sea trial tests. The difference of motions between them is great. For example, a VLCC in standstill can achieve a great alteration of heading over 90 degrees within the distance of 0.2L advance while she advances 3.0L for 90 degrees turning in full running sea trial turning test. Therefore whenever a VLCC in standstill meets a vessel approaching in collision course situation in near distance, it is better and recommendable that she should use her ahead engine with full rudder to avoid collision. So "maneuvering trial tests in standstill conditions" should be added to the content of sea trial tests when a newly built VLCC commence to take sea trials, that has not been included until now.

Analyses of Shear and Frictional Characteristics in Drilling Process (드릴링 공정의 전단 및 마찰 특성 해석)

  • Kim, Sun-Il;Choi, Won-Sik;Son, Jae-Hwan;Jang, Eun-Suk;Lee, Young-Moon
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.11 no.6
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    • pp.22-27
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    • 2012
  • Drilling process is usually the most efficient and economical method of making a hole in a solid body. However, there have been no analytical method to assess drilling process based on the shear and frictional characteristics. In this paper, procedures for analyzing shear and frictional processes of drilling have been established by adopting an equivalent turning system to drilling. A series of drilling experiments were carried out with varying feed, velocity and drill shape factors. Using the results of the experiments, the cutting characteristics including shear in the primary shear zone and friction in the chip-tool contact region of drilling process have been analyzed. The specific cutting energy tends to decrease exponentially with increase of feed rate. In drilling process 35-40% of the total energy is consumed in the friction process. This is greater than that of turning process in cutting of the same work material.

Roundabout Accident Model by Traffic Impeding Factor (교통 저해요소별 회전교차로 사고모형)

  • Cho, Ah Hae;Park, Byung Ho
    • Journal of the Korean Society of Safety
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    • v.32 no.1
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    • pp.128-133
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    • 2017
  • This study deals with the roundabout traffic accidents by traffic impeding factor. The purpose of this study is to comparatively analyze the characteristics of accidents and to develop the accident models. In pursuing the above, this study used a statistical program SPSS 20.0 to analyze 2,342 accidents occurred within 79 roundabouts in Korea. The main results are as follows. First, 4 accident models which were all statistically significant were developed. Second, the traffic volume and width of right-turn-only lane were analyzed to be common variable in the bus stop related models. The variables such as right-turn-only lane, street light, turning radius of entry lane were selected as specific variables. Especially street light and turning radius of entry lane were evaluated to have negative effects to the accidents. It is, therefore, essential to install the street light and place a sufficient turning radius in order to reduce the roundabout accidents. Finally, the traffic volume and number of entry lane were analyzed to be common variable in the on-street parking related models. Also, the width of right-turn-only lane and bus stop were evaluate to be specific variables in the model with on-street parking. This can be expected to give some implications to making the accident reduction guidelines.

Development of the Dynamic Model and Control Logic for the Rear Wheel Steering in 4WS Vehicle (후륜 조향 동력학 모델 및 제어 로직 개발)

  • 장진희;김상현;한창수
    • Transactions of the Korean Society of Automotive Engineers
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    • v.4 no.6
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    • pp.39-51
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    • 1996
  • In the turning maneuver of the vehicle, its motion is mainly dependent on the genuine steering characteristics in view of the directional stability for stable turning ability. The under steer vehicle has an ability to maintain its own directonal performance for unknown external disturbances to some extent. From a few years ago, in order to acquire the more enhanced handling performance, some types of four wheel steering vehicle were considered and constructed. And, various rear wheel control logics for external disturbances has not been suggested. For this reason, in this posed rear wheel control logic is based on the yaw rate feed back type and is slightly modified by an yaw rate tuning factor for more stable turning performance. And an external disturbance is defined as a motivation of the additional yaw rate in the center of gravity by an uncertain input. In this study, an external disturbance is applied to the vehicle as a form of the additional yawing moment. Finally, the proposed rear wheel control logic is tested on the multi-body analysis software(ADAMS). J-turn and double lane change test are performed for the validation of the control logic.

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Tool Holder Design and Cutting Force Measurement of Diamond Turning Process (다이아몬드 터닝의 미세 절삭력 측정을 위한 tool holder 설계 및 절삭력 측정)

  • Jeong, S.H.;Kim, S.S.;Do, C.J.;Hong, K.H.;Kim, G.H.;Rui, B.J.
    • Proceedings of the KSME Conference
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    • 2001.06c
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    • pp.507-512
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    • 2001
  • In this work, tool holder system has been designed and builted to measure cutting forces in diamond turning. This system design includes a 3-component piezo-electric tranducer. Initial experiments with tool holder system included verification of its predicted dynamic characteristics as well as a detailed study of cutting parameters. Tool holder system is modeled by considering the element dividing, material properties, and boundary conditions using MSC/PATRAN. Mode and frequency analysis of structure is simulated by MSC/NASTRAN, for the purpose of developing the effective design. Many cutting experiments have been conducted on 6061-T6 aluminum. Tests have involved investigation of velocity effects, and the effects of depth and feedrate on tool force. Forces generally increase with increasing depth of cut. Increasing feedrate does not necessarily lead to higher forces.

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A Study on Turning Characteristics of Vehicle Based on Parameters of Curved Road (매개변수에 따른 커브 길에서 차량 선회특성에 관한 연구)

  • Yang, Sung-Hoon;Lee, Hak-Yong;Yoon, Jun-Kyu
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.13 no.2
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    • pp.25-32
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    • 2013
  • Entry speed of the vehicle and lateral acceleration acting on the vehicle, roll-angle associated with the overthrow, and then the structure of the road, the friction of road surface are important factors in turning on the curved road. In this study, we analyzed the state change of the vehicle causing entry speed of the vehicle and superelevation of the road, the friction coefficient by using a PC-crash Program for traffic accident reconstruction. As a result, when vehicle is turning the curved road, we could ascertain that the structure of the road and state of the road surface are a major factor about the set up of limited speed.

Characteristics of Environment-friendly Semi-dry Turning (환경 친화적인 세미드라이 선삭가공 특성)

  • Lee, Jong-Hang;Lee, Sang-Jo;Lee, Seok-U;Choe, Heon-Jong
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.10
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    • pp.221-226
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    • 2002
  • As environmental restriction has continuously become more strict, machining technology has emphasized on development of environment-friendly technologies. In cutting technology, it has been well recognized that cutting fluids might have undesirable effects on workers health and working environment and, hence, recently there have been numerous attempts to minimize harmful effects of cutting fluids on environments. To minimize the use of cutting fluids in machining, conventional cutting fluids have been replaced with the technologies of pressurized cold air and minimum quantity lubrication (MQL). Compared with milling, turning is continuous cutting process, where tools are continuously heated up and lack of lubricity could lead to tool wear and deteriorated surface roughness. In this work, it has been investigated how tool wear and surface roughness could be affected by cutting conditions, supply and cooling methods. The experimental results show that MQL technology is able to minimize conventional cutting fluids.

Propelling and Turning Motions of Fish for Virtual Aquarium (가상 수족관 물고기의 추진과 회전 유영 생성 방법)

  • Han, yoon-seok;Yoon, jae-hong;Kim, eun-seok
    • Proceedings of the Korea Contents Association Conference
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    • 2008.05a
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    • pp.33-37
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    • 2008
  • The interaction between artificial fish and aquatic surroundings and the fish's realistic locomotion are very important elements to construct virtual aquariums. In general, the artificial fish in virtual aquariums used to be created by 3D modeling tools, and was repeatedly showing the simple and constant form of swimming. This paper will analyze the sorts of biological forms of fish-swimming and the propelling and turning characteristics. Then, we propose a method of the basic swimming and turning of artificial fish to generate various and natural-looking locomotion. It is possible to make a explorable virtual aquarium more immersive by using interactive interfaces together.

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