• 대한인간공학회지
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• 제30권2호
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• pp.285-290
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• 2011

Due to the ageing-related degradation in physical and cognitive abilities, the elderly have difficulty in car driving and this is related to the high rate of car accidents among them. This study investigated the kinematic characteristics of old drivers' steering in right turning at intersections by comparing with young drivers. Thirteen old(60~70) and thirteen young(20~30) drivers who participated in the experiment turned their cars right side at intersections in a driving simulator. As results, the completion time of right turning at intersection of old drivers was larger than that of young drivers. The speeds of vehicle at the beginning and ending point of the right turning area of old drivers were smaller than those of young drivers, and also the steering angle at the ending point of the turning area of the former was smaller than that of the latter. The normalized jerk of old driver's steering was significantly larger than that of young drivers. These results indicate that old drivers modify their steering movement repeatedly and take the driving strategy of avoiding risks due to their reduced physical capabilities.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.41-41
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• 2010

In this research, to study tungsten carbide alloy(Co 0.5%) ultra precision turning possibility that is used Glass Molding Press(GMP) using conventional (Rake angle $-25^{\circ}$) single crystal diamond bite observed machining surface condition, surface roughness($R_a$), diamond bite cutting edge after tungsten carbide alloy ultra precision turning. Suggested and designed optimum chamfer bite shape to suggest ultra precision optimum bite using Finite Element Analysis(FEM). After machining tungsten carbide alloy ultra precision turning using optimum chamfer bite and comparing with conventional bite machine result and studied optimum chamfer bite design inspection and also tungsten carbide ultra precision turning possibility for high temperature compression glass lens molding.

• 한국기계가공학회지
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• 제7권2호
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• pp.23-30
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• 2008

As a basic machining process, turning is a widely used machining process in which a single-point cutting tool removes material from the surface of a rotating material. A common method of evaluating machining performance is to measure the surface roughness. In a turning operation, it is important to select cutting conditions for achieving high cutting performance. As a rule, cutting conditions can be classified into feed rate, depth of cut and insert radius. While cutting process even though cutting conditions are optimized, the average roughness can be deterioration due to wear of the cutting tool edge. In this study, the aim is to maintain the average roughness even though the cutting condition is irregularly changing within the predictable range due to the working environment. First, the surface roughness model influenced by cutting conditions is constructed based on the experimental results in a turning operation, Second, applying the sliding mode control theory to the turning operation model which is composed of the surface roughness model and the motor transfer function, the surface roughness is closed to the desired value. Finally, the effectiveness of this approach is demonstrated through the computer simulation.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.529-533
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• 1996

Recently, manufacturing industries are doing their best to increase productivity and to reduce production time. One of tile efforts is to develop user-friendly and effective CAM systems. For this purpose, a CAM system for turning was developed. In the developed system. user interacts with tile CAM system using graphical user interface (GUI) and manufacturing support functions to make NC programs effectively. Manufacturing support functions include cycle decoder. interference check be ween tool and workpicce. bar turning without air cut and dynamic/wireframe simulation. In the cycle decoder. basic options are provided to novices for their convenience. and advanced options are provided to help expert to modify the program using their knowledge. Interference check has been nil issue in tile CAM system for tuning. In this paper. when a user selects a tool. interference check between selected tools and workpieces is done automatically. Moreover. remaining shapes are calculated automatically. Then, tile CAM system requests user to input all additional tool and generates NC codes to cut tile remaining shapes. In bar turning of forged raw material, air cut should be prevented for effective machining. For this purpose, a new algorithm for bar turning was developed. Dynamic and wireframe simulation was used to verify the generated NC code.

• 한국의류학회지
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• 제8권1호
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• pp.47-56
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• 1984

The purpose of this study was to classify somatotype and to investigate the 15 measurements for the clothing construction. The size of sample was 467 females between age 6 and 60. Analysis of Variance (ANOVA) was employed to analyze the 15 measurements by group and somatotype. The results of the study were as follows; 1) All the measurements were significantly different among the groups except the Vertebralis angle. 2) Concerning the upper part of the body, Standard somatotype was found more frequently in group IV. V compared with the other, Turning over somatotype in group I. II, Bending somatotype in group VI. VII. VIII. Concerning the under part of the body Standard somatotype was found more frequently in group IV. V. VI. VII. VIII. compared with the other, Forward-turning over somatotype of the lower help body and Turning over somatotype in group I. II. III. when the upper part of the body was turning over somatotype, the under part of the body was generally Turning over somatotype or Forward-turning over somatotype. When the upper part of the body was Bending somatotype, the under part of the body was commonly Forward somatotype.

• 한국기계가공학회지
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• 제19권10호
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• pp.36-43
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• 2020

A marine turning gear is the main auxiliary machine that enables the disassembly of and maintenance on the main engines. In this study, a marine turning gear based on a helical planetary reducer was developed through analysis of a marine turning gear based on a spur planetary reducer. Nonlinear numerical analysis was performed to determine the ideal contact ratio between the sun gear and the idle gear. Based on this, the surface durability, tooth bending strength, and contact ratio were calculated. In addition, the helix direction was selected to utilize the existing bearings. Gears were manufactured based on the helical gear design values, and the turning gear was evaluated using the FTA standards of MAN Co. Ltd. As a result, a lifetime of 3,000 to 5,000 hours was verified, the maximum torque measured was 105kNm, and the efficiency was measured to be 87.4%.

• 로봇학회논문지
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• 제16권4호
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• pp.319-326
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• 2021

To improve the driving performance and work efficiency of the multi-purpose agricultural robot, this paper conducted a study on the turning and steering characteristics of the robot platform according to the characteristics of the working machine coupled to the multi-purpose agricultural robot considering the agricultural environment. First, the size and characteristics of the developed multi-purpose agricultural robot platform and working machine, and the targeted field farming work environment are analyzed. And based on this analysis, the problems that arise in multi-purpose robots with conventional turning methods are quantitatively presented. And to overcome this problem, an improved turning and steering method for multi-purpose agricultural robots is proposed considering the characteristics of various workstations and the agricultural working environment. Finally, by applying the proposed method, the turning characteristics of the multi-purpose agricultural robot according to the working machine are analyzed and the effectiveness of the proposed method is verified.

• 한국정밀공학회지
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• 제14권8호
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• pp.73-81
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• 1997

The hard turning process defined as a single point turning of materials harder than $H_{R}$C 58 differs from conventional turning because of hardness of the work materials and cutting toos needed in the process. In hard turning, tool life is very short, of the order of a few minutes, during which the cutting tool is subjected to the extremes of stress and temperature. In this regard, it is well known that CBN tool is proper for this process in spite of expensive cost. In this research, we studied the feasibility of the use of the low cost cutting tool such as a aTiN coated tool. To this end, a new cooling system was designed with an air-oil method for reducing tool temperature, which is based on the principle of air vortex flow. That is, the outlet temperature of the air becomes aver 20 .deg. C lower than atmosphere temperature by entering pressurized air of 5kgf/c $m^{2}$ into the inlet. This cooled air ejected to the top of the cutting tool lowered tool temperature, which reduced the wear of a TiN coated tool by the 30% of CBN tool life with respect to the same cutting length.h.

• 한국식품저장유통학회지
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• 제20권2호
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• pp.151-157
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• 2013

본 연구에서는 수확시 숙성 정도가 토마토의 저장 중 품질변화에 미치는 영향을 구명하고자 하였다. 그린하우스에서 재배된 'Rafito' 품종을 각각 turning, pink, red 단계에 수확한 후 $30{\mu}m$ PE 필름으로 포장한 후 $5^{\circ}C$와 $10^{\circ}C$에 두어 1주일 간격으로 경도, 가용성 고형분 함량, 적정산도, 색, 라이코펜 함량, 부패율, 저온장해율을 조사하였다. 저장 3주 이후에 $5^{\circ}C$에서는 저온장해가 $10^{\circ}C$에서는 부패가 높게 발생되었다. $5^{\circ}C$에서는 수확 후 품질변화가 거의 없으므로 완숙과인 red 토마토의 품질 유지에 적합하였나, turning과 pink 토마토는 수확후 숙성과정이 억제되어 저장 2주 후에도 미숙한 상태에 머물렀다. Turning과 pink 토마토를 수확 후 $10^{\circ}C$에 저장하면 수확기에 비해 품질이 향상되었다. 특히, turning 토마토는 $10^{\circ}C$에 2주간 저장할 경우 연화는 억제되어 경도가 높게 유지되면서도, 착색이 완성되고 SSC/TA가 증가하며 라이코펜 함량이 완숙과 수준으로 증가되어 내 외부 품질이 가장 우수하였다. 따라서 red 단계에서 수확된 'Rafito' 토마토의 경우 부패를 억제할 수 있는 $5^{\circ}C$ 저장이 바람직하며, red 단계보다 미숙한 상태에서 수확할 경우 저온에서는 후숙에 의한 품질형성이 억제되므로 $10^{\circ}C$가 적정 온도인 것으로 판단된다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1926-1930
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• 2004

We suggest a turning gait planning of a quadruped walking robot with an articulated spine. Robot developer has tried to implement a gait more similar to that of natural animals with high stability margin. Therefore, so many types of walking robot with reasonable gait have been developed. But there is a big difference with a natural animal walking motion. A key point is the fact that natural animals use their waist-oint(articulated spine) to walk. For example, a crocodile which has short legs relative to a long body uses their waist to walk more quickly and to turn more effectively. The other animals such as tiger, dog and so forth, also use their waist. Therefore, this paper proposes discontinuous turning gait planning for a newly modeled quadruped walking robot with an articulated spine which connects the front and rear parts of the body. Turning gait is very important as same as straight gait. All animals need a turning gait to avoid obstacle or to change walking direction. Turning gait has mainly two types of gaits; circular gait and spinning gait. We apply articulated spine to above two gaits, which shows the majority of an articulated spine more effectively. Firstly, we describe a kinematic relation of a waist-joint, the hip, and the center of gravity of body, and then apply a spinning gait. Next, we apply a waist-joint to a circular gait. We compare a gait stability margin with that of a conventional single rigid body walking robot. Finally, we show the validity of a proposed gait with simulation.