• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.4
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• pp.23-32
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• 2012

The present study is aimed to develop an integrated performance analysis approach for the application of a compressor with variable inlet guide vane (VIGV) and vairable stator vane (VSV) in a small turbofan engine. For the integrated analysis approach, an engine performance analysis program, NPSS and a computer program used for predicting of axial flow compressor performance based on stage stacking method, STGSTK were linked with an optimisation package, Isight. This enables off-design performance analysis for the turbofan engine with VIGV and VSV hence provides the capability to predict stable operation condition of the engine with acceptable surge margin.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.3
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• pp.9-17
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• 2019

Variable guide vanes(VGVs) that consist of link mechanisms and an actuator system are required for an aircraft gas turbine engine to adjust the incidence angle of stator vanes. In this study, we developed a VGV actuator system for three-stage VGVs with two hydraulic actuators. The requirements for the actuator system were derived by analyzing the link mechanisms and air loads, and a hydraulic power-pack was developed based on these requirements. Through a load test using the actuator test-rig and the application of synchronizing control logic with proper control gains, the actuator system could be developed and verified.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.07a
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• pp.653-654
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• 2023

한국이 정보 선진국으로 발전함에 따라 노인들의 스마트폰 보유율은 증가하고 있지만, 디지털 환경에 대한 접근성과 경험 부족 등의 이유로 아직도 디지털 약자이다. 그런데도 노령층들이 쉽게 사용할 수 있는 노령자 전용 애플리케이션의 개발은 저조한 실정이다. 본 연구에서는 이러한 문제를 해소하기 위해 노령층을 대상으로 다양한 생활 정보를 제공하는 모바일 애플리케이션, 'Seniors Guide'를 개발하였다. 'Seniors Guide'는 사용자 거주지역 주민 센터의 자치 프로그램 정보, 노인 일자리 정보, TV 프로그램 알람, 투약 시간 알람 설정 기능을 제공하는 등 노령층에서 자주 이용하는 다양한 정보와 기능들을 하나의 애플리케이션에서 유용하게 사용할 수 있도록 하는 앱으로 구현되었다.

• International Journal of Oral Biology
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• v.41 no.4
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• pp.243-251
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• 2016

This study was undertaken to achieve a high bleaching efficacy with plasma, through longer application and reparative bleaching processes, by different shade evaluation methods. Extracted human teeth were divided into 6 groups (n=10). All teeth were treated in pairs. Low concentration of 15% carbamide peroxide (CP) was applied, with and without plasma, for 10, 20, and 30-min tooth bleaching, respectively. The bleaching procedure was repeated once daily for four days. The teeth were maintained in a moist environment provided by artificial saliva. The Vitapan Classical shade guide and Commission Internationale de L'Eclairage (CIELAB) color system were collectively used to measure the bleaching efficacy. Color evaluation was statistically analyzed using Student t-test and one-way analysis of variance (ANOVA) complemented by Tukey's test. Combining the plasma with 15% CP showed significantly greater color changes compared to bleaching without plasma (p<0.05). A high bleaching efficacy with plasma is proportional to the repetitive application and the treatment time. A 30-min application with plasma provided the best bleaching. Repetitive bleaching showed lower probability of color relapse of the bleached tooth. The color change by shade guide correlated with the changes in CIELAB color system. A value of 1 color change units (CCU) conversion factor for overall color change (${\Delta}E$) values comparisons was 3.724 values. The two measuring methods provide a more accurate correspondence of color change. The repetitive and longer application for tooth bleaching, combined with plasma, has a strong bleaching effect and produces whiter teeth.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.2
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• pp.86-91
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• 2012

A conductor has been produced according to IEC standard and low voltage electrical facility has been installed according to IEC 60364. So we must comply with international standard for design, construction and inspection. But because of many related and varied standards, it is difficult to apply to design and inspect for electrical equipment. We researched the necessity of design guide which is detailed and systematization from survey. For detailed design guide, we suggest calculation method of protective conductor cross-sectional area at TN-S system according to BS 7671 regulation and KS C IEC 60364 standard.

• Journal of the Korean Society of Systems Engineering
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• v.13 no.2
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• pp.26-33
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• 2017

Pyro project, one of complex project, is now under research and development. To manage this kind project successfully, it is essential to apply the processes of technical management (TM) based on systems engineering (SE) and project management (PM). In this paper, the project management processes from ISO-21500 standard, PMBOK guide, and PRINCE2 guide were reviewed, and then some common PM for the large national R&D project were selected. An integrated technical management and project management frame work was finally established and suggested for Pyro project.

• Journal of Korean Institute of Industrial Engineers
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• v.20 no.2
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• pp.77-90
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• 1994

Curve-net interpolation surface is one of the most popular method in engineering design. Therefore it is supported with many commercial CAD/CAM system. However, construction algorithm of curve-net interpolation surfaces is rarely opened to the public because of its copy-right. In this paper we establish a construction algorithm of curve-net interpolation surface so called sweeping surface which especially concentrates on trajectory of cross-section curve. We also show the method which can construct sweeping surfaces as NURB or Bezier mathematical models. Surfaces having the form of standard mathematical models are very useful for the application of joining, trimming, blending etc. The proposed surface interpolation scheme consists of four steps; (1) preparation of guide curves and section curves, (2) remeshing guide curves and section curves, (3) blending section curves after deformation, and (4) determination of control points for sweeping surface using gordon method. The proposed method guarantee $G^1$-continuety, and construct the surface salifying given section curves and trajectory of section curves.

• Journal of the Korean Society for information Management
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• v.6 no.2
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• pp.3-20
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• 1989

Hypertext system is a new type of electronic information system which offers users great freedom in writing and reading electronic documents. Hypertext means non-linear or non-sequential text, which consists of a collection of nodes connected by links. Nodes may contain segments of text, video images, and sound. In this paper, the concept and characteristics of hypertext are reviewed, components of hypertext are explored in detail, and Guide is illustrated with application examples.

• Journal of Ocean Engineering and Technology
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• v.19 no.4 s.65
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• pp.15-20
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• 2005

This paper presented the development of a new experimental and numerical technique for the investigation of slamming impact. The in-house code was developed, based on the boundary element method. The application of commercial code was attempted using FLUENT. Pneumatic cylinder and LM-guide were introduced to closely simulate the free fall phenomenon. It was demonstrated that the proposed experimental and numerical studies can be useful tools in investigating slamming phenomenon.

• International Journal of High-Rise Buildings
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• v.1 no.3
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• pp.237-246
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• 2012

Outrigger systems have been widely used in super tall buildings constructed since the 1980's, eclipsing previously favored tubular frame systems. However, outriggers are not listed as a seismic lateral load resisting system in any code. Design guidelines are not available. The CTBUH formed the Outrigger Working Group to develop the first-ever outrigger system design guide with an historical overview, considerations for outrigger application, effects on building behavior and design recommendations including concerns specific to this structural system such as differential column shortening and construction sequence impacts. Project examples are presented for various outrigger system types, including advancements in their technology. The guide provides a basis for future discussions on this important topic.