• Journal of Advanced Marine Engineering and Technology
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• v.32 no.6
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• pp.923-930
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• 2008

The butterfly valve is widely used in the industrial field as an on-off or a flow control valve. When the butterfly valve is used as a flow control valve. cavitation sometimes occurs in the range of high flow rate because of the small valve opening. Therefore. the pressure loss and the cavitation characteristics are investigated by use of a commercial CFD code. The results show that the possibility of cavitation occurrence in the cryogenic butterfly valve is very high in the case of valve opening angle below 10 degree and incident velocity over 6m/s. By increasing the inlet velocity at 10 degree of valve opening angle. the value of loss coefficient increased. However. by increasing the inlet velocity at 50 degree of valve opening angle. the value of loss coefficient decreased.

• Journal of the Korean Society of Clothing and Textiles
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• v.15 no.2 s.38
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• pp.139-150
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• 1991

The purpose of this study is to do the Somatotype classification according to the type of shoulder-neck and to give the thinkness of shoulder pad according to them. Therefore this study was measurement body size of 201 and the somatotypes were classified as their plumb line. The standard somatotype of this measurement was classified as 9 type according to its angle of shoulder inclination and neck length. Pads which have different thickness (1 cm, 1.5 cm, 2 cm) were attached to the 9 body type and the set-in sleeve blouse and raglan sleeve blouse were made and tring test and sensory test were accomplished. The results of this study were as follows: 1 . Classification of shoulder-neck relationship. Angles of shoulder inclination ($15^{\circ},\;21^{\circ},\;27^{\circ}$), lock lenaths (10 cm, 12.5 cm, 15 cm) were classi- fied as 3 type each and these types were combined as 9 types. II . The result of angle difference of shoulder inclination according to pad thickness. 1) In case of set-in pad. angle is increased $5.75^{\circ}$ per 1 cm of pad thickness. 2) In case of raglan pad. angle is increased $6.45^{\circ}$ per 1 cm of pad thickness. III. The most fit pad thickness to the 9 types. In case of set-in sleeve blouse. 1) High shoulder-long neck, Standard shoulder-long neck Low shoulder-long neck, Stan-dard shoulder·standard neck. Low shoulder-standard neck: 1.5 cm. 2) High shoulder-standard neck, Standard shoulder-short neck, Low shoulder-short neck: 1 cm. 3) High shoulder-short neck: 0 cm(without pad) In case of raglan sleeve blouse. 4) High shoulder-long neck, Standard shoulder-long neck, Low shoulder·long neck, Stan-dard shoulder-standard neck, Low shoulder-standard neck: 1.5 cm. 5) High shoulder-standard neck, Standard shoulder-short neck, Low-shoulder-short neck: 1 cm. 6) High shoulder-short neck: 0 cm(without pad)

• Journal of Korean Association for Spatial Structures
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• v.21 no.1
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• pp.105-112
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• 2021

In this paper, the dynamic response was analyzed by performing linear dynamic analysis using historic earthquake loads on twisted-shaped structures and fixed structure among free-form high-rise structures with atypical elevation shape following prior studies. In addition, the dynamic characteristics of the analysis models according to the plane rotation angle of the twisted structure were compared and analyzed. As a result of the analysis, as the plane rotation angle of the twisted structure increased, the interlayer deformation rate increased in the high-rise part of 50th floors or more. The story shear force and the story absolute acceleration were similar in the entire structure. In the case of the story shear force, the response of the twisted shape model was rather reduced in the middle part. As a result of analyzing the dynamic response, the vulnerable layer where the response amplification of the twisted structure occurs was found to be 31st story.

• The korean journal of orthodontics
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• v.46 no.4
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• pp.253-265
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• 2016

In the present report, we describe the successful use of miniscrews to achieve vertical control in combination with the conventional sliding MBT$^{TM}$ straight-wire technique for the treatment of a 26-year-old Chinese woman with a very high mandibular plane angle, deep overbite, retrognathic mandible with backward rotation, prognathic maxilla, and gummy smile. The patient exhibited skeletal Class II malocclusion. Orthodontic miniscrews were placed in the maxillary anterior and posterior segments to provide rigid anchorage and vertical control through intrusion of the incisors and molars. Intrusion and torque control of the maxillary incisors relieved the deep overbite and corrected the gummy smile, while intrusion of the maxillary molars aided in counterclockwise rotation of the mandibular plane, which consequently resulted in an improved facial profile. After 3.5 years of retention, we observed a stable, well-aligned dentition with ideal intercuspation and more harmonious facial contours. Thus, we were able to achieve a satisfactory occlusion, a significantly improved facial profile, and an attractive smile for this patient. The findings from this case suggest that nonsurgical correction using miniscrew anchorage is an effective approach for camouflage treatment of high-angle cases with skeletal Class II malocclusion.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.6
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• pp.98-105
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• 2019

In order to improve the fuel economy and dynamic behavior of automobiles, the weight reduction tendency of automobile parts is obvious. Also, in order to maximize assembly and maintenance convenience, various parts are integrated and modularized. Multi-piece methods require many manufacturing processes and become a factor of lowering the strength of parts. It is advantageous to overcome the disadvantages by integrally manufacturing to reduce the processing steps and ensure the strength of the parts. However, when it is necessary to process in a narrow space inside the part, it is impossible to process with the existing spindle. The angle head spindle is only a component of a machine tool, but it is a core part that requires high technology and is highly utilizable in products requiring high precision machining. Therefore, various and continuous studies needs for angle head spindles in areas such as vibration absorption, operational safety, excellent dimensional stability, and strength. In this paper, we propose an optimal design for angle head spindle by performing structural analysis and shape optimization for angle head spindle gear and case.

• 한국연소학회:학술대회논문집
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• 2004.06a
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• pp.242-247
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• 2004

An Experimental study was conducted on spray combustion using dual swirlers at different outlet angle; co-swirl and counter-swirl. To understand the characteristics of turbulent spray combustion of dual swirl flow (DSF), the axial helical annular vaned swirlers with various swirl ratios and combination of angle and direction were designed. and temperature measurements of a rapidly thermocouple insertion and measurements of soot volume fraction and microrstructure using thermophoretic sampling particle diagnostic (TSPD) as TEM were carried out. The NOx, $CO_2$, $O_2$, etc. was analyzed using emission gas analyzer. The results show that flame stability were maintained under very lean condition. for both co-swirl and counter-swirl case. And though Counter-swirl case kept the higher temperature region compared to co-swirl case, Counter-swirl combustion represented less NOx emission and soot formation than co-swirl case.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.790-793
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• 2009

In the case of projection type display, it needs to use the screen in order to project the image clearly and wide viewing angle. We have been developing the step in type display system using the smoke screen. However, the image with smoke screen was flickered by gravity and air flow. Then we considered to reduce the flicker of the image and we found that flicker can be reduced and viewing angle becomes more large. This time we report the large viewing angle step in type display system using screen made up with very small particle size smoke and flow controlled nozzle. Hence, at first we considered the most suitable particle for the screen and then the shape of screen and then we constructed the array of flow controlled smoke screen. By the results of experiment we could get considerably high contrast flicker-less image and get the viewing angle more than $60^{\circ}$ by this flow controlled nozzle attached new type smoke screen and make clear the efficiency of this method.

• Journal of the Society of Naval Architects of Korea
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• v.35 no.1
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• pp.80-87
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• 1998

This paper deals with the evaluation of structural safety to fatigue strength of marine propeller blades having high skew angle and operating in irregular wake field. The determination of the optimum skew angle of a propeller blade is one of the important task at the initial design stage especially in the case of high speed vessel such as container ships. A computer program system has been developed to evaluate the structural safety to fatigue strength and has been applied to several propeller blades with varying skew angle within a wide range. In the parametric study the pressure acting on the blade surface is calculated using the non-lineal lifting surface theory and the structural analysis is performed using MSC/NASTRAN. The relationship between skew angle and structural safety to fatigue strength is investigated and this paper ends with describing the optimum skew angle of a propeller blade.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.507-510
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• 2002

In economical points of view, AC loss of high temperature superconducting devices is considered as a serious problem that must be solved. Expecially, in case of HTS cables, HTS tapes are wound helically on the former to reduce AC loss. Critical characteristics of HTS tapes, however, are influenced by mechanical stress as well as electrical, temperature, and magnetical factors. The purpose of this study is to investigate the over current characteristics of HTS tapes given mechanical stress when they are wound on the former. We prepared HTS tapes with the pitch angle 20$^{\circ}$, length 25cm as well as tapes with pitch angle 0$^{\circ}$. When current of over 200A$\_$rms/ was applied, we found out that there are differences to the rate of resistance increase between the case of pitch angle 20$^{\circ}$and that of 0$^{\circ}$. The rate of resistance variation in HTS tapes of pitch angle 20$^{\circ}$increased more slowly than that of pitch angle 0$^{\circ}$. As a result, we concluded that if critical characteristics of HTS tapes are degraded by any external factor, when over current is applied, the current limiting characteristics in HTS tapes won't be able to be expected any more.

• IEMEK Journal of Embedded Systems and Applications
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• v.11 no.3
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• pp.183-191
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• 2016

Recently, in rehabilitation treatment, the situation that requires a measure of the accuracy of the pose and movement of joints is being increased due to the habits and lifestyle of modern people and the environment. In particular, there is a need for active automated system that can determine itself for the matching rate of pose Basically, a method for measuring the matching rate of pose is used by extracting an image using the Kinect or extracting a silhouette using the imaging device. However, in the case of extracting a silhouette, it is difficult to set the comparison, and in the case of using the Kinect sensor, there is a disadvantages that high accumulated error rate according to movement. Therefore, In this paper, we propose a method to reduce the accumulated error of matching rate of pose getting the rotation angle of joint by measuring the real-time amount of change of 9-axis sensor. In particular, it can be measured same conditions that unrelated of the physical condition and unaffected by the data for the back and forth movement, because of it compares the current rotation angle of the joint. Finally, we show a comparative advantage results by compared with traditional method of extracting a silhouette and a method using a Kinect sensor.