• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.342-345
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• 2006

The properties of reinforcing fiber, as tensile strength, aspect ratio and elastic modulus, have great effect on the fracture behavior of HPFRCC(High performance fiber-reinforced cementitious composite). Acoustic emission(AE) method was used to evaluate the characteristics of fracture process and the micro-failure mechanism of HPFRCC. For these purposes, three kinds of fibers were used : PP(Polypropylene), PE(Polyethylene), SC(Steel cord). In this study, the AE characteristics of HPFRCC with different fiber type(PE.15, PP2.0, SC0.75+PE0.75) distributions under four-point-bending were studied. The result show that the AE technique is a valuable tool to study the failure mechanism of HPFRCC.

• Journal of the Korean Institute of Rural Architecture
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• v.8 no.1
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• pp.90-100
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• 2006

The purpose of this study is to suggest a actual conditions and expert's role on the green tourism in rural community. There are four types of green tourism in rural villages. It is an alternative tourism that has naturalism and sustainability, not mass tourism. I can find it is a one of the new rural development method in a point of view of rural people's income. Green tourism requires a participation of village peoples. So, management hang on not government office, but village people themselves. By surveying green tourism villages in the case of this study, I propose a few results as follow; firstly, green tourism of Korea will give an innovation to stagnant rural society. Secondly, rural people themselves must participate directly in development and guidance, when every programs are advanced. Thirdly, through this project of green tourism, we expect that urban and rural symbiosisically have a network.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.5
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• pp.1240-1255
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• 1996

This paper suggests power optimization technique in multi-level SCPC system as a method for efficient utilization of limited satellite power. The power optimization is realized by optimal assignment of satellite input carrier powers considering interference and noise generated in up-link and down-link. The Fletcher-Powell algorithm searching minimum(or maximum) point using gradient information is used to detemine the optimal input carrier powers. To apply Flectcher-Powell algorithm mathematical descriptions and their partial derivatives to interference and nose are presented. Because a target, which should be optimized, is satellite input carrier power, amplitude of each carrier group will be assumed to be an independent variable. The performance criterion for optimal power assignmentis classified into 4 categories with respect to CNR of destination receiver earth station to meet the requirement for various satellite link environment. Simulation results for two-level, four-level and six-level SCPC system are presented.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.6
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• pp.483-488
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• 1999

The optimal mixing condition of four components gas(Ne,Xe,He,Ar) in PDPs was caculated by a numerical simulation method. The dominated reactions in which $Xe^*(^3P_1)$ is produced and decays were investigated in three components gas (Ne,Xe,He) and our new components gas (Ne,Xe,He,Ar). A peak point of $Xe^*$ density appears in the range of 0.1% to 2% of Ar mixture ratio. The results of simulation show that the direct exitation of Xe by electrons has the greatest influence on the inceasing $Xe^*$ density in both gas mixtures.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.336-336
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• 2010

Ga doped ZnO (GZO) transparent conductive films were deposited on the glass substrates at room temperature by facing target sputtering (FTS) method. The sputtering targets were 100 mm diameter disks of GZO($Ga_2O_3$ 3.w.t%) and Zn metal. The GZO thin films were deposited as a various $PO_2$ (oxygen gas content). Base pressure was $2{\times}10^{-6}$torr, and a working pressure was 1mTorr. The properties of thin films on the electrical and optical properties of the deposited films were investigated by using a four-point probe, a Hall Effect measurement and an UV/VIS spectrometer. The minimum resistivity of film was $6.5{\times}10^{-4}$[$\Omega$-cm] and the average transmittance of over 80% was seen in the visible range.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.29A no.8
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• pp.49-55
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• 1992

We Have investigated the properties of the titanium nitrite films widely used in VLSI devices as diffusion barrier in Al-based metallization. TiN films were formed by reactive sputtering from Ti target in Ar-N$_2$ mixtures, varying deposition parameters such as N$_2$ partial pressure, substrate temperature, power, and total pressure. All the samples received the heat treatment at 45$0^{\circ}C$ for 30 min. The resulting films are characterized by mechanical stylus($\alpha$-step), x-ray diffraction(XRD), scanning electron microscopy(SEM), and four point probe method. The Tin film properties strongly depend on the deposition condition. The stoichiometry and Ti deposition rate are critically affected by nitrogen partial pressure, and the resistivity, in particular, is dependent on both the substrate temperature and sputtering power.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.2 no.3
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• pp.90-95
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• 2003

The W-EDM is very important In precision machining of die, punch and small parts of precision products, so this machining method is widely used in various fields of industry. In this study, machining characteristics of Hand Drum Form and surface roughness are investigated experimentally. As Hand drum form has great effect on straightness of cut-surface of workpiece, its evaluation is very important in precision cutting. As experimental material, the mold material, STD11 is used and machined by CNC wire-EDM using the 025mm wire in diameter with repeated cutting up to 6 times. The thickness of workpiece is vaned in 20, 40, 60, 80, 100mm Hand drum form and surface roughness are measured after each cutting. Experimental results show that four times-cutting is optimum in the point of hand drum form and surface roughness.

• Journal of the Korean Society of Costume
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• v.50 no.6
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• pp.155-162
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• 2000

Classifying the diverse and complex clothing category of nationality subcultures in China is not a simple task. However, summing up, it can be largely classified that clothing of the northern area is long trousers and short skirt. Among the clothing of Nationality in China, especially, Pao(robe: 袍) has its diversity and colorfulness. whose elements forming its each characteristic feature has enough value to be investigated fully in the historical point of view. The conclusions of this study reveals that Pao in nationality subculture in China can possibly be divided into the four types as Qipao(旗袍) in Dongpei area, Mongopao(蒙古袍) in Inner Mongolia, Qiapan in Xinjiang area, and Zangpao in Tibet area. The modes of Qipao and Mongopao are mainly similar in that they have diagonally on the right, stand collar in composition, but Qipao shows its diversity in collar and slashes, and Mongopao also shows diversity in its colare and waistband. Since western culture flowed into China along with its open door and reform policy, the splendid color and distinctive pattern, decoration, diversified method of compositions and clothing categories of Nationality cultures are disappearing in its their originality and nationality.

• The Korean Journal of Community Living Science
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• v.15 no.1
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• pp.57-65
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• 2004

The purposes of this study are to identify types of fathers who engaged in different patterns of interaction with their children and to examine the characteristics by different fathering patterns. Data are collected from 323 married men with the oldest child under 12 years old, using the structured questionnaire survey method. The major findings of the study are as follows: First, the fathering activities are composed of four factors, which are affective involvement, caretaking, social involvement and discipling. The respondents tend to exhibit the level of fathering activities higher than middle point. Second, using cluster analysis, three types of fathers are categorized: The affective type fathers scored significantly high on dimensions of affective involvement. Whereas the engaged fathers scored the highest on all domains of fathering, the disengaged fathers demonstrated significantly limited involvement. Third, the characteristics which are associated with fathering activities patterns are father's age, job type, work hour, frequency of meetings after work hour, job satisfaction and child rearing attitude. The results of this study suggest several implications to develop parent education program for fathers and their children.

• Journal of the Korean Society for Precision Engineering
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• v.8 no.4
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• pp.118-125
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• 1991

Acoustic microscopy has attracted much interest recently as potential nondestructive evaluation technique for detecting and sizing defects of surface and sub-surface. Also acoustic emission testing method has been developed for detecting microcracks which is more than 30${\mu}m$ in length quantitatively on ceramics. In the present paper, acoustic emission during the four point bending test in hot-pressed sintered $Si_3N_4$ specimen which was stressed by thermal shock, has been measured by high sensitive sensing system. The surface and sub-surface cracks were detected by scanning acoustic micrscope of 800 MHz and conventional ultrasonic testing in C-scope image. The purpose was to investigate the location and size of cracks by SAM and AE technique, whose experimental data demonstrate good for detecting microcracks.