• Title/Summary/Keyword: point-contact

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A Study on e-Business Establishment Model : Furniture Industry (e-비즈니스 구현 모델에 관한 연구 : 가구산업 중심으로)

  • Lee, Young-Min;Ju, Sang-Ho
    • Journal of Information Technology Services
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    • v.1 no.1
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    • pp.67-80
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    • 2002
  • This study aims to explore the ways of reinforcing the competitive edge and substance of company through e-business in furniture industry by presenting the e-business model of furniture industry which faces the opportunity of challenge in the course of industrial restructuring. e-business model can take various types depending on the environment, feature and competitive edge that each company faces. For example, it is general in the fields of manufacturing company to study the model by dividing into Sell Side for sales to the customers, and Buy Side for purchase of raw materials, Integrating both sides. In furniture industry, Sell Side has the feature of giving a priority in the quality and price rather than brand image in the purchase type of consumer. Especially, it shall not be overlooked that majority of furniture is delivered to the consumer indirectly through the construction company. As such, e-business should be promoted in a way to expand the point of contact for consumers, rather than to construct its own point of contact for consumers. The percentage of importation of raw lumber is high and the standardization was insufficient in Buy Side.

Measurement and Investigation of Apparent Masses of a Human Body at the Sitting Posture in a Passenger Car (승용차 착석 자세에서의 인체 겉보기 질량 측정 및 고찰)

  • Jang, Han-Kee;Hong, Seok-In;Kim, Ki-Sun;Lee, Jeong-Hoon;Kim, Kwang-Joon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.11a
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    • pp.369-374
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    • 2004
  • This study aims to measure an apparent mass of a seated human body at the sitting posture in a passenger car in the frequency range from 1 to 20 Hz and to investigate the dynamic characteristics. Thirty subjects joined the test where eight levels of acceleration from $0.1m/s^2\;to\;2.0m/s^2$ were used to excite seated human body. Most of apparent mass curves showed two peaks in the frequency range of $4\sim9Hz$, first peak was clearer at the contact point of the seat and the hip, and the second one at the contact point of the backrest and the back. Both peak frequencies were found to move down to lower frequencies with increase of acceleration magnitude. Shapes of apparent mass curves were clearly different from those at erect posture especially in the frequency range around and above the second peak.

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Artificial Neural Network for Stable Robotic Grasping (안정적 로봇 파지를 위한 인공신경망)

  • Kim, Kiseo;Kim, Dongeon;Park, Jinhyun;Lee, Jangmyung
    • The Journal of Korea Robotics Society
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    • v.14 no.2
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    • pp.94-103
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    • 2019
  • The optimal grasping point of the object varies depending on the shape of the object, such as the weight, the material, the grasping contact with the robot hand, and the grasping force. In order to derive the optimal grasping points for each object by a three fingered robot hand, optimal point and posture have been derived based on the geometry of the object and the hand using the artificial neural network. The optimal grasping cost function has been derived by constructing the cost function based on the probability density function of the normal distribution. Considering the characteristics of the object and the robot hand, the optimum height and width have been set to grasp the object by the robot hand. The resultant force between the contact area of the robot finger and the object has been estimated from the grasping force of the robot finger and the gravitational force of the object. In addition to these, the geometrical and gravitational center points of the object have been considered in obtaining the optimum grasping position of the robot finger and the object using the artificial neural network. To show the effectiveness of the proposed algorithm, the friction cone for the stable grasping operation has been modeled through the grasping experiments.

Requirements of Fashion as Popular Art in Contemporary Culture

  • Seunghee, Suh
    • Journal of Fashion Business
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    • v.26 no.6
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    • pp.94-104
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    • 2022
  • The purpose of this study is to analyze the art world's perspective on popular art and the contact point with pure art and to present the requirements of fashion as a popular art. To analyze the artistic value of fashion, this study analyzed and presented the requirements of art by linking the innate characteristics of fashion premised on mass consumption of popular art. The research method consisted of content analysis focusing on books and papers on art and fashion. A critical perspective on expansion of the artistic field amid the blurred boundaries of art is the basis of a critical comparison between popular art and avant-garde art and a critique of popular art as opposed to value-oriented art. Conversely, as a point of contact with popular art with fine art, art is discussed against the ideological strategy of fine art and the shift in hegemony brought about by erosion of the barrier between art and everyday life. In addition, the non-essentialist perspective contradicts the division theory of popular art. The requirements of fashion as a popular art were analyzed based on the value of self-expression through the aesthetic pursuit of creativity and aesthetic expression, discourse as art, and expansion of modern art from the inessentialist perspective of popular art.

On the Supplementary Study on DSM-Based Interface Requirements through Analysis of the Operation Scenario of the Urban Subway Logistics System

  • Hwang, Sunwoo;Kim, Joouk;Park, Jaemin;Lee, Sangmin;Kim, Youngmin
    • International Journal of Internet, Broadcasting and Communication
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    • v.14 no.1
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    • pp.152-161
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    • 2022
  • Recently, it is recognized as a high-cost and inefficient logistics system that increases traffic congestion and environmental problems due to an increase in traffic volume due to the activation of the online market. In order to solve inefficient problems such as unavoidable traffic congestion and environmental problems caused by the increase in traffic volume, it is necessary to develop a freight transport system technology using the existing urban railway infrastructure and freight-only urban railway. The urban subway logistics system is a logistics system that requires a combination of various technologies to solve the nationwide demand for urban logistics and road traffic problems. This paper recognized the existing traffic congestion and environmental pollution of road traffic as problems, and supplemented the contact point requirements presented above by identifying the sub-systems constituting the target system and supplementary points for each part-level contact point. In this study, as a complex system operated for one purpose by grafting various technologies, a plan is required to secure the reliability and safety of operation from various viewpoints. The results of this study can contribute to the initial configuration and basic data to solve the interface bottleneck of the urban subway logistics system to be promoted in the future.

A Study on Shape Design of Cylindrical Cam with Rotating Roller Follower in Roller-Gear-Cam Mechanism (롤러기어캠 기구를 위한 회전운동형 롤러 종동절을 가진 원통 캠의 형상 설계에 관한 연구)

  • Sin, Jung-Ho;Gang, Dong-U;Yun, Ho-Eop
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.8
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    • pp.1527-1533
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    • 2002
  • When a mechanism transfers a motion to an intersected shaft, a cylindrical cam mechanism may be the best choice among the mechanisms. The cylindrical cam with a roller follower provides to transfer the motions to the intersect shafts simply without other connecting equipments of the intersect shafts. Typical example may be a roller-gear-cam mechanism. But the shape of the cam must be exactly defined in order to satisfy the conditions for the prescribed motion of the follower. This paper proposes a new method for the shape design of the cylindrical cams and also a CAD program is developed by using the proposed method. The relative velocity method calculates the relative velocity of the follower versus the cam at a center of roller, and then determines a contact point by using the geometric relationships and the kinematic constraints. The constraint used in the relative velocity method is that the relative velocity must be parallel to a common tangent line at the contact point of two independent bodies, i. e. the cam and the follower. Then, the shape of the cam is defined by the coordinate transformation of the trace of the contact points. Finally, this paper presents an example in order to prove the accuracy of the proposed methods in this paper and the application of the CAD program"CamDesign".

An experimental study on the fretting fatigue crack behaviour of A12024-T4 (A12024-T4의 프레팅 피로균열거동에 관한 실험적 연구)

  • Lee, Bong-Hun;Lee, Sun-Bok
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.21 no.3
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    • pp.511-518
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    • 1997
  • The technique of fretting fatigue test was developed and fretting fatigue tests of A12024-T4 were conducted under several conditions. The newly developed calibration methods for measuring surface contact tractions showed good linearity and repeatability. The plate type specimen to which tow bridge type pads were attached and vision system was used to observe the crack behaviour. The oblieque cracks appeared in the early stage of crack growth and they became mode I cracks as they grow about 1 mm. The mode I transition points were found to be longer when surface tractions are higher or bulk stress is lower. Before the crack becomes mode I crack, 'well point' where crack grow about rate is minimum, was detected under every experimental condition. The crack behaviour was found to be affected by surface tractions, contact area, bulk stress. It was also found that partial slip and stick condition is most detrimental and the crack starts from the boundary of stick and slip. For gross slip crack started at the outside edge of pad. After crack mode transition, fretting fatigue cracks showed almost same behaviour of plain mode I fatigue cracks. Equivalent stress intensity factor was used to analyze the behaviour of fretting fatigue cracks and it was found that stress intensity factors can be applied to fretting fatigue cracks.

보철 수복시 치간 유두에 대한 고려 사항

  • Lee, Sung-Bok;Lee, Seung-Gyu
    • Journal of the Korean Academy of Esthetic Dentistry
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    • v.10 no.1
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    • pp.30-45
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    • 2001
  • In recent years, clinicians' and dentists' esthetic demands in dentistry have increased rapidly. The ultimate goal in modern restorative dentistry is to achieve "white" and "pink" esthetics in the esthetically important zones. Therefore, modern esthetic dentistry involves not only the restoration of lost teeth and their associated hard tissues, but increasingly the management and reconstruction of the encasing gingiva with adequate surgical techniques. Interdental space are filled by interdental papilla in the healthy gingiva, preventing plaque deposition and protecting periodontal tissue from infection. This also inhibits impaction of food remnants and whistling through the teeth during speech. These functional aspects are obviously important, but esthetic aspects are important as well. Complete and predictable restoration of lost interdental papillae remains one of the biggest challenges in periodontal reconstructive surgery. One of the most challenging and least predictable problems is the reconstruction of the lost interdental papilla. The interdental papilla, as a structure with minor blood supply, was left more or less untouched by clinicians. Most of the reconstructive techniques to rebuild lost interdental papillae focus on the maxillary anterior region, where esthetic defects appear interproximally as "black triangle". Causes for interdental tissue loss are, for example, commom periodontal diseases, tooth extraction, excessive surgical periodontal treatment, and localized progressive gingiva and periodontal diseases. If an interdental papilla is absent because of a diastema, orthodontic closure is the treatment of choice. "Creeping" papilla formation has been described by closing the interdental space and creating a contact area. In certain cases this formation can also be achieved with appropriate restorative techniques and alteration of the mesial contours of the adjacent teeth. The presence of an interdental papilla depends on the distance between the crest of bone and the interproximal contact point, allowing it to fill interdental spaces with soft tissue by altering the mesial contours of the adjacent teeth and positioning the contact point more apically. The interdental tissue can also be conditioned with the use of provisional crowns prior to the definitive restoration. If all other procedures are contraindicated or fail, prosthetic solutions have to be considered as the last possibility to rebuild lost interdental papillae. Interdental spaces can be filled using pink-colored resin or porcelain, and the use of a removable gingival mask might be the last opportunity to hide severe tissue defects.

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Three-dimensional Kinematic Analysis of the Yurchenko Layout with 360-degree Twist in Female Vaults: Deterministic Model and Judges' Scores

  • Park, Cheol-Hee;Kim, Young-Kwan
    • Korean Journal of Applied Biomechanics
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    • v.27 no.1
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    • pp.9-18
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    • 2017
  • Objective: The purpose of this study was to identify kinematic variables that govern successful performance and judges' scores and to establish correlative relationships among those of Yurchenko layout with a full twist in female vaults. Method: Four video cameras with sampling rate of 60 Hz collected 32 motion data of Yurchenko vaults from twenty-two female participants (age: $18.6{\pm}3.6years$, height: $153.0{\pm}6.5cm$, mass: $44.7{\pm}7.3kg$) during national competition. Posting processing and calculations of kinematic variables were performed in Kwon 3D XP and $Matlab^{(R)}$ programs. Correlation and regression analyses were applied to find the relationships between the obtained scores and kinematic variables. Deterministic model (Hay & Reid, 1988) was used to investigate the strength of correlative relationships among kinematic variables. Results: The obtained scores from the judges' decision were mainly affected by post-flight peak height, horse contact time, knee angle at landing, and horse takeoff angle. Strong blocking during horse contact was required to get successful performance and obtain high scores. Modified deterministic model showed that round-off entrance and takeoff angles and resultant velocity of the center of mass (CM) during the roundoff phase were the starting variables affecting performance in the following kinematics. Knee angle at landing, a highly influential variable on the obtained point, was only determined by judges' decision without significant correlative relationship with previous kinematic variables. Conclusion: The obtained scores highly depended on kinematic variables of post-flight and horse contact phases that were affected by those from the previous phases including round-off postures and resultant velocity of the body center of mass.

The effect of impurities implanted single-Si substrates on the formation of $TaSi_2$ (단결정 실리콘 기판에 이온주입된 불순물이 $TaSi_2$형성에 미치는 영향)

  • Jo, Hyun-Chun;Choe, Jin-Seok;Go, Chul-Gi;Baek, Su-Hyeon
    • Korean Journal of Materials Research
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    • v.1 no.1
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    • pp.17-22
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    • 1991
  • Tantalum thin films were deposited by DC sputtering on heavily doped single Si substrates. These substrates were treated by means of a rapid thermal annealing (RTA) under Ar atmosphere for various temperatures($600-1100^{\circ}C$). The silicide formation and the impurities behavior in the substrate are studied by means of XRD, SEM, four-point probe, HP4145, and SIMS. The formation of $TaSi_2$ started at $800^{\circ}C$ for all kinds of impurities and the entire Tantalum thin metal films were transformed into $TaSi_2$ above $1000^{\circ}C$ Also the contact resistance for $TaSi_2/P^+$ region had a low value; $22{\Omega}$, at contact site of $0.9{\times}0.9(\mu\textrm{m^2}$), and implanted impurities were diffused out into the $TaSi_2$ for rapid thermal annealing.

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