• 로봇학회논문지
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• 제11권1호
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• pp.26-32
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• 2016

A variable release torque-based compliance spring-clutch (VCSC) is presented. VCSC is a safe joint to reduce the impact of collisions between humans and robots. It is composed of four functional plates, balls, springs to make some functions in compliant movement, release mechanism, gravity compensation during its work. Also, it can estimate torque applied to a joint by using distance sensor and parameters of cam profile. The measured variable torque of prototype is 4.3~7.6 Nm and release torque is 4.3 Nm. In our future studies, a calibration for torque estimation will be conducted.

• Journal of Mechanical Science and Technology
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• 제14권3호
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• pp.283-290
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• 2000

To maintain the specific volumetric efficiency of a heavy-duty diesel engine, an understanding of the behavior of each part of the valve train system is very important. The stiffness of the valve train system has a strong influence on the behavior of the valve train than valve clearance, heatresistance, or the durability of parts. In this study, a geometrical cam design profile using a finite element model of the valve train system is suggested. The results of the valve behavior according to the change in stiffness is analyzed for further tuning of the valve train system.

• Restorative Dentistry and Endodontics
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• 제22권1호
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• pp.244-253
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• 1997

During preparation of narrow curved canals, procedural accidents such as, ledge, zipping, and transportation are frequently encountered and may lead to failure of endodontic therapy. To reduce these procedural errors and efficiently manage curved canals, various modifications in instrumentation technique and the design and flexibility of instruments have been advocated. This study compared the maintenance of the original canal curvature, cross sectional canal shape, and preparation time during instrumentation with stainless steel hand (K-Flexo) file, and nickel-titanium rotary files (Profile and Lightspeed). Thirty resin blocks with simulated curved canals of 20~25 degrees were used and divided into three groups of 10 each. In group 1, canals were instrumented using a quarter turn/pull technique with K-Flexofiles. Group 2 canals were prepared with rotary NiTi Profiles. Group 3 was prepared with rotary NiTi Lightspeed instrument. Before and after instrumentation, all canals were scanned using stereo microcope, FlexCam camera, and Photoshop 3.0 computer program. The results were as follows : 1. All groups showed some loss of canal curvature after instrumentation. Average loss of canal curvature was 8.6 degrees for K-Flexofile, 7.7 degrees for Profile, and 5.8 degrees for Lightspeed. Lightspeed exhibited significantly less curvature loss than K-Flexofile (p<0.05). 2. At the apical 1-mm level, Profile produced significantly rounder canals than Lightspeed (p<0.05). At the 3-mm level, Profile and Lightspeed exhibited significantly rounder canals than K-Flexofile (p<0.05). 3. Preparation with Lightspeed was significantly faster than Profile and K-Flexofile, and Profile was faster than K-Flexofile (p<0.05). 4. There was no significant difference in incidence of zipping between the hand K-Flexofile and rotary NiTi (Profile and Lightspeed) instruments. Most of apical canals were slightly widened near the apical foramen. As a results of this study, rotary NiTi instruments are superior to the K-Flexofile in regard to the maintenance of original canal curvature, cross-sectional shape and preparation time. But more investigations and studies should be needed to evaluate the ideal canal instrumentation.

• 소성∙가공
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• 제7권3호
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• pp.246-259
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• 1998

This paper describes a research work of developing a computer-aided design and manufacturing of irregular shaped sheet metal product for blanking or piercing and bending operations. An approach to the system is based on the knowledge-based rules. Knowledge for the system is formulated from plasticity theories experimental results and the empirical knowledge of field experts, This system has been written in AutoLISp on the AutoCAD and in customer tool kit on the SmartCAM with a personal computer and is composed of nine modules which are input and shape treatment, flat pattern-layout, pro-processor module. Based on the knowledge-based rules, the system is designed by considering several factors, such as material and thickness of product complexities of blank geometry and punch profile sheet metal to give flat pattern and automatically account for the adjustment of bending allowances to match tooling requirements by checking dimensions and generating NC data automatically according to drawings of die-layout module. Results carried out in each module will provide efficiencies to the designer and the manufacturer of blanking or piercing and bending die in this field.

• 한국CDE학회논문집
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• 제8권2호
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• pp.115-121
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• 2003

A new Layered Manufacturing(LM) system, named PaperMill, is developed applying micro milling technology. A micro endmill(127 11m in diameter) is introduced as the cutter of build material. The selected build material for this system is an adhesive-coated paper roll which provides advantages such as good bonding between layers, machinability, and low material cost. A 3-axis CNC controller and three step-motors are used for the movement of X-Y-Z table of the system. For simplicity of the control of mechanism, the control system for feeding the paper roll is uncoupled from CNC controller. Two code converters are developed for the toolpath generation of the new LM system. The NC converter generates a set of NC codes for PaperMill using commercial CAM software while the SML converter generates an NC code from Quickslice's SML format. The NC codes generated from the converters consist of a series of profile data and trigger code for paper feeding. Two sample gears were fabricated to prove the concept of the system, which shown that the dimensional errors of the fabricated gears is under 3.4 percent.

• 한국의류산업학회지
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• 제25권6호
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• pp.725-731
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• 2023

With the development of technology, many changes have emerged in how consumers acquire information without restrictions on their location and time. As changes and interest in digital platforms increase, beauty industry applications are being developed in order to attract customers. Therefore, this study has provided the empirical data necessary for the development and advancement of beauty applications in the future by analyzing preferences for makeup applications according to age. The method of this study involved searching for makeup applications that had been downloaded more than 100 million times through the Google Play Store between October 11, 2020 to November 3, 2020. Four applications were identified: YouCma Makeup, YouCam Perfect, Beauty Plus, and Sweet Snap. The surveyed functions were tested on 100 people in their teens, 20s, 30s, and 40s, with a similar profile of 100 people in their teens, 20s, 30s, and 40s surveyed from January 3, 2022 to April 23, 2022. The functional preferences of the application were investigated, and the results were analyzed through frequency analysis. The results are as follows: the application that received the greatest preference for features by age was YCM, which was found to have subdivided functions that provide users a wider range of choices and more detailed work when compared to other applications which enable photo retouching.

• 한국생산제조학회지
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• 제7권4호
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• pp.96-103
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• 1998

With the advance of processing technology , so as to spare fuel, piston heads used in automobile reciprocating engine have complex 3-dimension, with respect to shape such as ovality, profile, eccentricity, offset, recess. Therefore, coming out of the existing process work used master cam. the process work is performed using a CNC lathe. For a precision processing, the processing work is need to make study of high speed feed gear synchronized with the rotative speed of main spindle. And then the high speed feeding system must maintain high dynamic stiffness, high speed and high positioning accuracy . In this paper, in order to achieve high speed cutting tool feeding. The linear brushless DC motor is used for satisfying this process work. The ball bush and turicite is used as the guidance of the feed gear system. Also linear encoders, digital servo amplifiers and controller are used for controlling driving motor. This paper presents the design and simulation of the new tool feed system for noncircular machining.

• 대한예방한의학회지
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• 제15권3호
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• pp.67-81
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• 2011

Background : Complementary and alternative medicine has bee used to cardiovascular diseases. In recent years, many hospitals have tried to integrate complementary and alternative medicine(CAM) with conventional medical approaches for patients with chronic diseases. Recently, the prevalence of the use of traditional Korean medicine(TKM) among patients with chronic diseases, expecially, hemiplegia patients after cerebrovascular accident is increasing in Korea. To date, however, there were only few studies addressing the patients' attitudes, and utilization of TKM, compared to the well-documented escalating use of TKM among consumers in Korea. Objectives : The objective of this study was to analyze the prevalence of TKM use among hemiplegia patients after cerebrovascular accident and to determine what factors affect to use CAM among the patients. The study also aims to provide information on TKM and assist therapy selection among various CAM therapies for hemiplegia patients after cerebrovascular accident within health care system in which both practitioners of TKM and practitioners of modern Western medicine coexisted. Methods : The design of the study was descriptive cross-sectional, and data were collected using a 32-items questionnaire. The subjects were one hundred fifty nine patients with chronic diseases who visited or admitted to health care facilities in a hospital in Seoul Metropolitan city, Korea. Data were analyzed using 'SPSS Statistics 18.0 Network Version(on release 18.0.1 of PASW Statistics)' program. Various statistical methods were used to obtain a profile for participants and the therapies most frequently used by hemiplegia patients of TKM. Logistic regression analysis was employed in order to determine the predicting variables of TKM use. Results : The prevalence of the use of TKM was 51.6%. The most common TKM therapies used by the patients included acupuncture(93.2%), herbal medicine(64.8%), and cupping(37.5%). Results of logistic regression analysis revealed that the variables significantly related with TKM use were gender, marital status, job, No. of visiting health care facilities/week. Conclusions : This study shows that the use of TKM among the hemiplegia patients is relatively high in Korea, this topic should be taken into account in the development of a holistic approach for patients with chronic diseases and an efficient chronic disease management system in Korea.

• 대한치과교정학회지
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• 제47권2호
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• pp.130-141
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• 2017

The aim of this case report was to describe an innovative orthodontic treatment method that combined surgical and orthodontic techniques. The novel method was used to achieve a positive result in a case of moderate crowding by employing a computer-guided piezocision procedure followed by the use of clear aligners. A 23-year-old woman had a malocclusion with moderate crowding. Her periodontal indices, oral health-related quality of life (OHRQoL), and treatment time were evaluated. The treatment included interproximal corticotomy cuts extending through the entire thickness of the cortical layer, without a full-thickness flap reflection. This was achieved with a three-dimensionally printed surgical guide using computer-aided design and computer-aided manufacturing. Orthodontic force was applied to the teeth immediately after surgery by using clear appliances for better control of tooth movement. The total treatment time was 8 months. The periodontal indices improved after crowding correction, but the oral health impact profile showed a slight deterioration of OHRQoL during the 3 days following surgery. At the 2-year retention follow-up, the stability of treatment was excellent. The reduction in surgical time and patient discomfort, increased periodontal safety and patient acceptability, and accurate control of orthodontic movement without the risk of losing anchorage may encourage the use of this combined technique in appropriate cases.