• Journal of the Korean Society of Clothing and Textiles
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• v.36 no.1
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• pp.84-98
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• 2012

This study examines the children's wear purchasing behavior of younger generation women (the missy group) and in the new-silver generation (retired). The data collected in the study were examined with a view to establish effective marketing strategies within the children's wear market, a market where the age and characteristics of the actual purchasers of the products have become more diverse. A descriptive survey method using a self-administered questionnaire was employed. The sample consisted of 398 females between the ages of 28 and 64 residing in Seoul and the Gyeonggi-do area. Data collected were analyzed by frequency, t-test, ANOVA, factor analysis, cluster analysis, and Cronbach's alpha coefficients. Respondents were classified into 4 groups by their clothes shopping orientation: conformable/brand conscious purchasing type, planned purchasing/enjoy shopping type, store/brand loyal impulse-oriented type, and dependent/low shopping interest type. There were differences between the missy and the new- silver generations under consideration. It is clear from the study that, even though some individuals of the missy group and of new-silver group belonged to the same shopping orientation type, individuals still showed differences with regard to children's wear purchasing behavior.

• Journal of Power Electronics
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• v.16 no.2
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• pp.731-747
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• 2016

The droop-based control strategy is widely applied in the interfacing inverters for distributed generation. This can be a problem since low-frequency stability issues may be encountered in droop-based microgrid. The objective of this paper is to classify, evaluate and compare various low-frequency damping methods. First, low-frequency stability problems are analyzed and an equivalent model of a droop-controlled inverter is investigated to classify the damping methods into the source-type damping strategies and the impedance-type damping strategies. Moreover, the lead-lag compensation network insertion control is proposed as a beneficial part of the source-type damping strategies. Then, the advantages and disadvantages of the different types of damping methods are theoretically evaluated and experimentally tested. Furthermore, the damping methods are comprehensively compared to illustrate the application field of each method. Finally, the synthesis of different damping methods to enhance the low-frequency stability is discussed and experimental validation is presented.

• The KSFM Journal of Fluid Machinery
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• v.11 no.3
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• pp.22-29
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• 2008

Clean and renewable energy technologies using ocean energy give us non-polluting alternatives to fossil and nuclear-fueled power plants to meet establishment of countermeasures against the global warming and growing demand for electrical energy. Among the ocean energy resources, wave power takes a growing interest because of its enormous amount of potential energy in the world. Therefore, various types of wave power conversion system to capture the energy of ocean waves have been developed. However, suitable turbine type is not normalized yet because of relatively low efficiency of the turbine systems. The purpose of this study is to investigate the internal flow and performance characteristics of a cross-flow type hydro turbine, which will be built in a caisson for wave power generation. Numerical simulation using a commercial CFD code is conducted to clarify the effects of the turbine rotation speed and flow rate variation on the turbine characteristics. The results show that the output power of the cross-flow type hydro turbine with symmetric nozzle shape is obtained mainly from Stage 2. Turbine inlet configuration should be designed to obtain large amount of flow rate because the static pressure and absolute tangential velocity are influenced considerably by inlet flow rate.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2109-2111
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• 2005

The effect of arc like streamer discharge is investigated on the hydrogen generation in the plasma reactor with multineedle - plate electrode geometry and SDR (Plasma reactor using the surface discharge). An additive of the two type (the saw type and the pellet type) was placed under the water surface to investigate the effect of the water surface conditions. The experimental results are compared in case of the reactor with and without an additive on the water surface. The generation of arc streamer discharge is more powerful with increasing applied voltage in the saw type. The maximum hydrogen Production concentration is about 4300 ppm at 74W in the SDR with additive of the saw type. Also, the Energy yield of the SDR (28990 g/kWh, 4300ppm, 74W) is higher than of the multineedle - plate electrode geometry (20892g/kWh, 3300ppm, 77W).

• Korean Journal of Metals and Materials
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• v.47 no.4
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• pp.248-255
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• 2009

A micro thermoelectric device was processed by electroplating the n-type Bi-Te nanowires and ptype Sb-Te nanowires into an alumina template with 200 nm pores. Power generation characteristics of the micro devices composed of the Bi-Te nanowires, the Sb-Te nanowires, and both the Bi-Te and the Sb-Te nanowires were analyzed with applying a temperature difference of $40^{\circ}C$ across the devices along the thickness direction. The n-type Bi-Te and the p-type Sb-Te nanowire devices exhibited thermoelectric power outputs of $3.8{\times}10^{-10}W$ and $4.8{\times}10^{-10}W$, respectively. The output power of the device composed of both the Bi-Te and the Sb-Te nanowires decreased to $1.4{\times}10^{-10}W$ due to a large electrical resistance of the Cu electrode connecting the Bi-Te nanowire array with the Sb-Te nanowire array.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.705-711
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• 2000

This paper presents a fast 3D mesh generation method using a surface based method with a stitching algorithm. This method uses the surface based method since the volume based method that uses 3D Delaunay triangulation can hardly deal with a large scale of scanned points. To reduce the processing time, this method also uses a stitching algorithm: after dividing the whole point data into several sections and performing mesh generation on individual sections, the meshes from several sections are stitched into one mesh. Stitching method prevents the surface based method from increasing the processing time exponentially as the number of the points increases. This method works well with different types of scanned points: a scattered type points from a conventional 3D scanner and a cross-sectional type from CT or MRI.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.6
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• pp.323-327
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• 2006

In this paper a new wire-wire discharge system with a slit dielectric harrier has been proposed, and, its corona discharge and ozone generation characteristics have been investigated experimentally. When the slit mica barrier is installed between corona wires, instead of the grounded plate electrode, a significant increase in the generation of ozone, about 2.2 times higher than that of the conventional ones without the slit harrier, could be obtained. Photographs show that this type of discharge system with a slit barrier was found to produce a corona discharge twice, once from the upper and bottom corona wires, and. again from both sides of surfaces and slits of the slit barrier. As a result, the proposed discharge system has the potential to increase significantly ozone production and it may be useful as an effective means for removing pollutant gases.

• Proceedings of the Korean Society of Computer Information Conference
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• 2016.01a
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• pp.219-222
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• 2016

블록형 구조물의 구축은 완구의 목적으로 널리 사용되고 있으며 이외에도 제품 디자인을 위한 래피드 프로토타이핑 및 창의학습을 위한 도구로도 활용되고 있다. 본 논문은 블록형 구조물을 적은 비용으로 손쉽게 설계하고 구축하기 위하여 블록형 구조물 자동 생성 기능 및 편집 기능을 제공하는 소프트웨어 시스템을 개발하였다. 본 시스템을 이용하여 가상공간에서 자유롭게 블록형 구조물을 생성 및 편집할 수 있고, 실제 구조물의 조립을 위한 매뉴얼로 활용할 수 있다.

• Journal of the Korean Ceramic Society
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• v.37 no.1
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• pp.90-95
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• 2000

The ferrites, CuFe2O4 and SrFe12O129, were applied to decompose H2O for H2 generation. The ferrites prepared by the coprecipitation were reduced by CH4 gas to make the oxygen deficient ferrite. H2O was decomposed to form H2 by the oxygen deficient iron oxide, and the decomposition reactions were accelerated by the addition of divalent metals such as Cu and Sr in the ferrites. The spinel type CuFe2O4 containing a relatively large amount of divalent metals was more effective to H2 generation than magnetoplumbite type SrFe12O19 in H2O decomposition.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1116-1117
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• 2007

In this paper, the control method of maximum power point tracking (MPPT) using the duty ratio control of buck-type dc/dc converter is presented for seaflow generation system. The advantage of the proposed MPPT method is that characteristics of seaflow generator(SG) with respect to seaflow speed, required in the conventional MPPT method, are not needed. Also, due to using the SG output power as a control parameter, neither characteristics of the seaflow speed nor measurements of the rotational speed of the generator are required. Thus, there are advantages that seaflow generation system having features of lower cost and complexity, and higher reliability can be designed. In this paper, Seaflow generation system using the buck-type dc/dc converter is proposed and the effectiveness of the MPPT algorithm is confirmed by matlab simulink.