• 연구논문집
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• s.32
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• pp.77-84
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• 2002

A martensitic precipitation hardening stainless steel, 17-4PH has been widely used in the aircraft, chemical and nuclear industries for long time, owing to the excellent mechanical properties with corrosion resistance that can be achieved by simple heat treatment. The microstructure and mechanical properties of the 17-4PH stainless steel cast parts for aircraft, such as impeller, are largely affected by heat treatment condition. But the database of heat treatment has not been clearly established in the domestic investment casting industries because the domestic aerospace, industry lags behind the advanced countries. In this study, the microstructural evolution and mechanical properties of cast 17-4PH stainless steel depending on the heat treatment conditions and aging at $400^{\circ}C$ were investigated.

• Journal of the Korean Ceramic Society
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• v.12 no.3
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• pp.3-7
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• 1975

The usefulness of the domestic shale contained chiastolite as additive were investigated. Crude mixed minerals were separated into shale and chiastolite. Refractory body added simple component or multiple components as additives was obtained when firing at 125$0^{\circ}C$ for each body. Compressive strength, refractories, apparent sp. gr., water absorption, corrosion test by slag, hot linear expansion were measured and X-ray diffraction analysis was observed. As the result of study, refractory body contained separated minerals as additives showed slightly increasing in refractoriness, lowering in sintering effect, the excellent effect for corrosion resistance by acidic slag. With more containing separated minerals, hot linear expansion for the body can be decreased.

• Fashion & Textile Research Journal
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• v.17 no.4
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• pp.597-603
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• 2015

This study investigates the actual domestic and overseas cyclewear wearing conditions for male high school cyclists. The study results provide factors and degree of dissatisfaction as basic data for cyclewear development. This study was conducted on 35 male high school cyclists (freshman to seniors) by a questionnaire and interview method. Study results were: Male high school cyclists considered functionality as most important when they bought cyclewear and the brand they most often bought was a cheap domestic brand. Dissatisfaction with the crotch, thigh circumference and minimum leg circumference was higher than other parts during wearing. A cyclist is more sensitive to wear because they require more lower body motion than other parts. Cyclewear should be: less transformed even by frequent laundering, made of breathable material and use a sewing technique that minimizes air resistance and increases fit the body. Functional pads ergonomically designed with high tactile materials should be developed to prevent 'saddle sore' and groin soreness region that happens because of a lower body bending posture when cycling. A follow-up study is recommended to further develop excellence in cyclewear functionality and dimension suitability for male high school cyclists through the size system.

• Journal of Animal Environmental Science
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• v.20 no.4
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• pp.189-194
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• 2014

A new tall fescue variety (Festuca arundinacea Schreb.) named Greenmaster and Purumi were. In this study, we evaluated the seed production of new tall fescue domestic varieties were cultivated in Korea. Agronomic aspects of tall fescue domestic varieties were determined using seed production and forage nutritive value of straw at the National Institute of Animal Science from 2013 to 2014. The heading date according to the varieties displayed differences and domestic varieties showed enhanced disease resistance. The harvested seed yields of Greenmaster was 35% higher as 1,664 kg/ha and it's also yield of straw higher than that of Fawn. However, the nutritive value of both varieties was similar. The dry matter yield of Pumumi was 25% higher as 11,080 kg/ha. Accordingly, developed a new variety of domestic tall fescue with excellent environmental adaptability, aiming to make contribution to the vitalization of the Korean grassland industry.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.5
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• pp.89-99
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• 2017

Although the technological innovation activities have depended on corporate, organizational and personal capabilities and activities, innovation resistance to practice was not actively considered in previous studies. This study is intended to the effects of corporate technology innovation capabilities and activities on intra-organizational innovation resistance and performance by compensating the limit of previous studies. To achieve this, a survey was empirically carried out to 293 domestic IT and BT companies. First, technological innovation competencies had a positive effect on technological innovation resistance, adopting hypothesis 1. Second, technological innovation activities had no positive effect on technological innovation resistance, rejecting hypothesis 2. Third, technological innovation resistance had a positive effect on technological innovation performance, adopting hypothesis 3. Fourth, technological innovation resistance was positively mediated in the relationship between technological innovation competencies and technological innovation performance, adopting hypothesis 4. Fifth, technological innovation resistance was not positively mediated in the relationship between technological innovation activities and technological innovation performance, rejecting hypothesis 5. Overall, the higher technological innovation competencies had a significant effect on technological innovation resistance. Consequently, technological innovation resistance can improve or reduce technological innovation competencies and performance depending on the level of resistance.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.11a
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• pp.189-193
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• 2007

The grounding of an electrical system is one of the essential elements for public safety. Domestic practice of grounding system design has been to get grounding resistance values which are classified by facilities or equipment in the regulations. But the concept of grounding system design of IEC is, as a main factor of safety index, to consider touch voltage and step voltage instead of the resistance value itself. Recently IEC actively develops or revises safety related standards which are essential for the grounding system performance. In this paper, we present the recent trend of the international standards on the safety criteria for Electric Shock Protection.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2002.05a
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• pp.13-20
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• 2002

Recently, as the tripolis where the construction of the high-rising building is actively advanced domestic, it will be able to resist in the various horizontal load with the resistance system against hereupon to arrange R.C wall in Core Portion in order, like this building the core construction must preceding from the steel structure and it will reduce using of steel frame amount and it will be able to reduce a whole construction cost with a horizontal resistance ability from the report which provides a reference data to the similar project after to analyze the application of the mivan formwork system which relates in Tripolis.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.5
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• pp.14-20
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• 2020

In this study, the overall states of the airflow when a truck with or without side pairing is driven at a maximum speed of 90 km/h, regulated by domestic law, were investigated through computational fluid dynamics numerical analysis. All the tested models showed that the airflow went under the truck body; specifically, the air did not flow along the underside to the rear of the truck but through the sides of its underside. The drag with the drag coefficient at model 3 was clearly higher than those for the other two models. The results of this study could help to improve the truck performance by reducing its resistance against the air flown from it in driving itself.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2001.11a
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• pp.57-61
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• 2001

In a main propulsion system of naval ship, DRME(Double Resilient Mounted Engine) is mostly adopted to ensure vibration isolation and shock resistance against underwater explosion weapon attack. In this paper, an analysis program for vibration and shock evaluation of DRME is presented. DRME is modelled as multi-rigid bodies with nonlinear mounts, and direct time integration method is introduced for shock analysis. The computed results are compared with those of foreign ones. Navy's proposed specifications are well satisfied with this program. This analysis program serves for the development of domestic DRME technology of naval ship.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.04a
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• pp.65-68
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• 2008

Intumescent coating system for fire resistance has undesirable weaknesses that fire resistance performance of steel members is being deteriorated due to cracks and falling-offs of the coverings as time goes after completion of the coverings to the members. This study is designed to understand changes in durability of intumescent coating system through follow-up tests on bond strength and thickness for the domestic intumescent coating system.