• Progress in Superconductivity and Cryogenics
• /
• v.16 no.2
• /
• pp.42-46
• /
• 2014

In this study we investigated ac transport current losses in the face to face stack for the anti-parallel current flow, and compared the electromagnetic properties with those of the single SC tape as well as those of the same stack for the parallel current path. The gap between the SC tapes in the stack varied in order to verify the electromagnetic influence of the neighbors when current flows in opposite direction, and the model was implemented in the finite element method program by the commercial software, COMSOL Multiphysics 4.2a. Conclusively speaking, the loss was remarkably decreased for the anti-parallel current case, which is attributed the magnetic flux compensation between the SC layers due to the opposite direction of the current flows. As the gap between SC tapes was increased, the loss mitigation became less effective. Besides, the current density distribution is very flat cross the sample width for the narrower gap case, which is believed to be benefit for the power electric system. These results are all in good agreement with those predicted theoretically for an infinite bifilar stack.

• Journal of Biosystems Engineering
• /
• v.41 no.1
• /
• pp.1-11
• /
• 2016

Purpose: The gear strength of a new mechanical transmission designed to increase the loading weight of small 4.8 kW tracked agricultural transporters was analyzed. Design improvements to increase the gear strength and reduce the gear weight were proposed after examining the parameters. Methods: Sixteen operators from three regions were surveyed to obtain the usage profile of small 4.8 kW transporters. Gear strength was evaluated by calculating contact stress and tooth root stress using commercial software following ISO 6336. Results: From the strength calculation for each gear pair, contact stress smaller than tooth root stresses were produced in all gear pairs. The safety factors in most cases exceeded 1.0, except in the case of gear pair II in group II. The design life of the transporter using gear pair II in group II was 42% under harsh conditions-thus, this design life needs improvement. A robust design was proposed by examining the relevant parameters (face width and profile shift coefficient) to increase the design life of the transporter. In addition, a lightweight design for gear pair I in group II that was considered overdesigned was proposed by examining the face width to reduce the weight of the drive gear by 42% and that of the driven gear by 30%. Conclusions: The Safety factor for the design life was examined through a gear strength analysis. After examining the relevant parameters, conditions for strength improvement were proposed to increase design life or adjust overdesigned gear. However, load conditions differ depending on the working conditions or user's preferences; therefore, it is necessary to conduct further studies in various regions.

• Journal of the Korean Society for Precision Engineering
• /
• v.3 no.3
• /
• pp.40-71
• /
• 1986

By developing a computer program for the systematic design of worm gears, the design formulae and tables of AGMA, JGMA, BS and DIN are analized and compared. The computer program can be used on micro-computers. According to the input data of the reduction ratio, the center distance. the driving torque and the material as design parameters, the program calculate the most efficient worm gear dimension. The variation of the design parameters and other empirical coefficients in case of resulting an inadequate design gear dimension can be easily modified throuth the way of interactive method between the user and the monitoring system of computer. A proposal of the standardization of worm gears was made in which a standard module according to the DIN 323 standard series number was applied. For the more exact and effective calculation of the stress concentration and the deformation of gear teeth, a computer program using the boundary element method is also developed. Even the strength of the special gear shape such as Niemann's "Cavex" gear can be calculated in a short CPU-time. The most effort of this study has been layed on the developing a computer program for the correction of a tooth profile and face width which is most important design factor for an exact and wide teeth contacts under loads, especially by great and wide gears. For this purpose were investigated the tooth stiffness, the mesh interferences and the kinematics and the dynamics of gear mesh. The deflection and the deformation of the gear shaft due to the loads acting on gear and shaft were aslo considered. Some examples have shown the sufficient good status of teeth contact in which the correction of the tooth profile and face width were accomplished due to the calculated results.d results.

• Science of Emotion and Sensibility
• /
• v.5 no.4
• /
• pp.1-10
• /
• 2002

A web based virtual try-on provides customers a more enjoyable shopping experience that visualize clothes on personal mannequin. The researchers compared virtual fitting models which were developed in 2000 at Korea and in 2000 and 2002 at U.S. The results of this study as follows: The information about user's body size was required to input for selection of a virtual fitting model. 7 to 19 different body size, shape, and face features including weight and height were needed for visualizing virtual fitting model. The body type of the U.S virtual fitting model(My virtual model) was selected by front view silhouette for women, and by shoulder width and midriff silhouette for men. The more detailed information was required for developing Korean virtual fitting model. The additional body size information required in the site were leg and arm lengths, waist length, and thigh and ankle circumferences. The body proportion of Korean cyber personal mannequin was longer and narrower than the U.S cyber personal mannequin. It was recommended that standardized body length, width, and depth proportions calculated from national anthropometric data must be applied for developing Korean virtual fitting model. With application of more detailed information on face feature and advanced graphic image technology the 'My virtual model in 2002 resembled the human body shape of various race.

• Korean Journal of Oriental Medicine
• /
• v.17 no.2
• /
• pp.115-120
• /
• 2011

Objectives : The purpose of this study is to develop an apparatus which can take a facial image by self-operated capturing technique. The user can obtain one's facial image immediately after adjusting facial tilt and focusing distance. The system has been designed for classifying Sasang typology based on facial image. Methods : The system is composed of a Webcam, one-way glass mirror and mini LCD. The Webcam takes a facial image which is displayed on the mini LCD. Then the user can see and adjust to the right position in the real time through the image mirror-reflected from the mini LCD. The optical sensor is used to estimate the proper focusing distance. To verify the performance of the system, 11 characteristic points on the facial image are used and compared with high performance DSLR camera(D700) by applying the coefficient of variance and Bland-Altman Plot. Results : The developed system and D700 show enough agreement with the small coefficient of variance to analyse constitutional types with a facial im mage. However, the result of Bland-Altman plot shows that the width parameters have distortions owing to short focusing distance. Conclusions : The system is expected to be utilized on u-healthcare services for home environment after improving the distortion in the width parameters.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.38 no.2
• /
• pp.185-192
• /
• 2014

Planetary gear design is complex because it involves a combination of discrete variables such as module, integer variables such as the number of teeth, and continuous variables such as face width and aspect ratio. Thus, an optimum design technique is needed. In this study, we applied a genetic algorithm to the design optimization of a planetary gear. In this algorithm, tooth root strength and surface durability are assessed with fundamental variables such as the number of teeth, module, pressure angle, and face width. With the help of this technique, gear designers could reduce trial and error in the initial design stages, thus cutting the time required for planetary gear design.

• Journal of Korea Society of Industrial Information Systems
• /
• v.11 no.4
• /
• pp.82-92
• /
• 2006

In the field of image recognition, research on face recognition has recently attracted a lot of attention. The most important step in face recognition is automatic eye detection researched as a prerequisite stage. Existing eye detection methods for focusing on the frontal face can be mainly classified into two categories: active infrared(IR)-based approaches and image-based approaches. This paper proposes an eye region detection method in non-frontal faces. The proposed method is based on the edge--based method that shows the fastest computation time. To extract eye region in non-frontal faces, the method uses edge orientationhistogram of the global region of faces. The problem caused by some noise and unfavorable ambient light is solved by using proportion of width and height for local information and relationship between components for global information in approximately extracted region. In experimental results, the proposed method improved precision rates, as solving 3 problems caused by edge information and achieves a detection accuracy of 83.5% and a computational time of 0.5sec per face image using 300 face images provided by The Weizmann Institute of Science.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.23 no.2
• /
• pp.115-123
• /
• 2001

The primary method of diagnosis in craniofacial deformity patient is used by gross inspection. The study for objective analysis and evaluation in Korean maxillofacial soft tissue portions is rare and our normals have been based on Caucasian such as American. But it is difficult to apply it to ours so we studied the frontal photometric measurements for maxillofacial Korean normals. The photograph were taken with the subject sitting in head position parallel with interpupillary plane to the floor. During taking pictures, facial analyser by Obwegeser in Martin was used for correct measurements. 54 male and 57 female ages 14 to 15 years were selected from a group of 111 healthy middle school students in Inchon. 1. The vertical measurements in glabella-subnasale, subnasale-stomion and stomion-menton in the male were higher than in the female subjects in $14{\sim}15$ years old Korean, so middle and lower third face were higher than those of female(p<0.05). 2. The horizontal measurements of female was higher than those of male in the rt. and It. eye width but smaller in nose width and lip width(p<0.05). 3. There was no significant difference in gender compared with soft cheek and mention angle measurements When our reports were compared with american white population, the vertical proportions in Korean normals were similar to american and the line measurements in middle facial length, nose width and intercanthal distance were higher than those of american.

• Geomechanics and Engineering
• /
• v.22 no.6
• /
• pp.541-552
• /
• 2020

With the increasing tension of current coal resources and the increasing depth of coal mining, the gob-side entry retaining technology has become a preferred coal mining method in underground coal mines. Among them, the technology of the gob-side entry retaining with the high-water filling material can not only improve the recovery rate of coal resources, but also reduce the amount of roadway excavation. In this paper, based on the characteristics of the high-water filling material, the technological process of gob-side entry retaining with the high-water filling material is introduced. The early and late stress states of the filling body formed by the high-water filling materials are analyzed and studied. Taking the 8th floor No.3 working face of Xin'an coal mine as engineering background, the stress and displacement of surrounding rock of roadway with different filling body width are analyzed through the FLAC^3D numerical simulation software. As the filling body width increases, the supporting ability of the filling body increases and the deformation of the surrounding rock decreases. According to the theoretical calculation and numerical simulation of the filling body width, the filling body width is finally determined to be 3.5m. Through the field observation, the deformation of the surrounding rock of the roadway is within the reasonable range. It is concluded that the gob-side entry retaining with the high-water filling material can control the deformation of the surrounding rock, which provides a reference for gob-side entry retaining technology with similar geological conditions.

• The korean journal of orthodontics
• /
• v.26 no.2 s.55
• /
• pp.197-204
• /
• 1996

This study was performed to mark the criteria of the eathetic smile that was necessary to improve the esthetic problem in oral maxillo-facial region. The facial straight photographs of 62 adults(30 males, 32 females : 19-24 years old) in resting position and during smile were taken. The measurements and proportion of lip-teeth relationship during smile were statistically analyzed with photogrammetry. The following results wow obtained : 1. In the evaluation of the change of lips, smile line ratio was 0.93, buccal corridor ratio was 0.63, and smile symmetry ratio was 0.96. 2. The width of mouth during smile was 1.31 times of the width inthe resting position and 0.48 times of face width. 3. The upper lip height during smile was 0.69 times of the height in the resting position and the lower lip height during smile was 0.93 times of the height in the resting position. 4. The mean exposed lenght of upper central incisor was 9.96mm. Maxillary incisor exposure was significantly correlated with the upper lip change ratio, mouth width change ratio, and buccal corridor ratio.