• 한국자동차공학회논문집
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• 제8권6호
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• pp.79-86
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• 2000

The effects of recirculated exhaust gas on the wears of piston and piston rings were investigated by the experiment with a two-cylinder, four cycle, indirect injection diesel engine operating at an engine load of 75% and an engine speed of 1600 rpm. For the purpose of comparison between the wear rates of two cylinders with and without EGR, the recirculated exhaust gas was sucked into one of two cylinders after the soot contenets in exhaust emissions were removed by an intentionally designed cylinder-type scrubber equipped with 6 water injectors(A water injector has 144 nozzles of 1.0 mm diameter), while only the fresh air was inhaled into the other cylinder. These experiments were carried out on the fuel injection timing fixed at 15.3$^{\circ}$ BTDC. It was found that the wear rate of piston skirt with EGR increased a little bit, but the piston head diameter increased, rather than decreased, owing to soot adhesion and erosion wear, and especially larger with EGR, and that the wear rates of the top and second piston ring(compression ring)thickness with EGR were more than twice the wear rate of top ring in case of no EGR, but the wear rate of oil rings thickness without EGR increased greater than that with EGR.

• 한국해양환경ㆍ에너지학회지
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• 제1권1호
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• pp.29-38
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• 1998

본 논문은 조류와 파랑중에서의 유벽의 성능에 관하여 저자들이 지난 수년간 수행한 연구 견과론 요약하여 수록하고 있다. 유벽의 성능 파악을 위해서 조류중 유벽의 누출개시 속도 예측, 파랑중 운동, 조류중 스커트의 변형에 관한 연구를 수행 하였다. 그 결과 해상 조건에서 유벽이 효과적인 보유 장비로서 활용되기 위해서는 그 보유 성능의 향상이 절대적으로 필요하다는 결론을 얻었다. 유벽의 보유 성능을 향상시키기 위한 한 방편으로 유벽을 이중으로 설치하는 방식의 효용성을 검토하였다. 연구를 통하여 동일한 형상의 유벽을 이중으로 적절히 설치함으로써 유벽의 보유 성능을 현격히 증대시킬 수 있다는 것을 입증하였다.

• Tribology and Lubricants
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• 제26권6호
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• pp.336-340
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• 2010

Ultrasound thermography detects defects by radiating 20 ~ 30 kHz ultrasound waves to the samples and capturing the heat generated from the defects with the use of an infrared thermographic camera. This technology is being spotlighted as a next-generation NDE for the automobile and aerospace industries because it can test large areas and can detect defects such as cracks and exfoliations in real time. The heating mechanism of the ultrasound vibration has not been accurately determined, but the thermomechanical coupling effect and the surface or internal friction are estimated to be the main causes. When this heat is captured by an infrared thermographic camera, the defects inside or on the surface of objects can be quickly detected. Although this technology can construct a testing device relatively simply and can detect defects within a short time, there are no reliable data about the factors related to its detection ability. In this study, the ultrasound thermography technique was used to manufacture gasoline and diesel engine piston specimens, and nondestructive reliability tests to verify the applicability and validity of the ultrasound thermography technique.

• 대한가정학회지
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• 제38권1호
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• pp.1-8
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• 2000

In this study 61private brand skirts and 67 brand name skirts were compared to see if the skirts from the different markets were suitable for both comfort and movement. The researcher chose size 66 skirts with a waist circumference of 68~70cm and hip circumference of 92cm. The resets are as follows. (1) In the waist measurement, the minor brand skirts were made at the maximum measurement (70cm) and the department store brand skirts were at the minimum (68cm). (2) Compared with the standard back split length of 9cm for a 48cm-long skirt, the minor brand skirts had a split of only 4.5cm, while the department store brand skirts were 3cm less (split length-6cm). From this result, we see that both of them are less practical than they are supposed to be (3) For the department store skirts, the hip circumference and waist circumference show a significant correlation to skirt length (p<0.05) and back split length (p<0.001). Larger waist & hip measurements equal longer split length. For the minor brand skirts, the length of the split shows a significant correlation to the depth of the hem-line Shorter split equals smaller hem depth. From these results, it can be concluded that the two groups of skirts do not differ except for back split length and waist circumference, but regarding the split length, both of them should be modified for else of movement and comfort.

• 한국의상디자인학회지
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• 제14권2호
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• pp.101-111
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• 2012

The purpose of this study is to evaluate the differences of visual image on variations in the length and princess line, in a silhouette of a one-piece dress with the application of the 3D Virtual Clothing System known as i-designer. Eight sample were examined: 2 variations of the length and 2 variations of the princess line, 2 variations of the form of a silhouette. The data was obtained from 66 fashion design majors. The data was assessed by a t-test and a multi-way ANOVA and factor analysis. The results were as follows; The visual image according to the design variables, four factors were selected; the attractiveness factor, the activeness factor, the practicality factor, the elegance factor. In these factors, the attractiveness factor is estimated by the most important factor. As a result of analyzing the effect of the interaction in the visual image according to the design variables, the influence of the main effect was found to be great in each factor. In the activeness factor, a significant difference was noted in the two-way interaction between the length and the princess line, the length and the silhouette. In the elegance factor, a significant difference was noted in the two-way interaction between the length and the silhouette. However, the influence on three-way interaction among the length, the princess line, and the silhouette was not significant.

• 한국의류산업학회지
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• 제6권4호
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• pp.447-454
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• 2004

The purpose of this study is to identify the effect of four clothing cues(hue, tone, skirt width, and skirt length of dress) on female impressions. The experimental materials developed for this study are a set of stimuli and response scales. The Stimuli are 40 color pictures manipulated with four clothing cues by drawing. The 7-point scale designed for visual evaluation of female impression formation includes 29 bipolar adjectives. The subjects were 240 undergraduate female students in Jinju city. The results of this study are as follow: As analyzing the impression of the female figure by the hue, tone, skirt width, and length, five factors including ability activity, elegance, attractiveness, concentration of attention, and tenderness were identified. Among these factors, ability activity and elegance were proved to be more important. Each impression of hue and tone with skirt width length have significant effects on concentration of attention, and tenderness. We can express various impressions by diversifying hue and tone. Each impression of skirt width length with hue and tone have significant effects on ability activity and elegance.

• 한국의류산업학회지
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• 제12권2호
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• pp.214-218
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• 2010

This research was to judge on the gathered skirt's shape by visual images that was from the different gathered skirts according to different sewing conditions; fabrics(cotton, mixed-wool, polyester), ratio of gathers(1.5T, 2.0T, 2.5T). Questionnaire consists of 33 semantic differential scale expressing gathered skirt's image, and 10 items of the shape were measured by 3D measurements method. The data were analyzes by factor analysis, correlation analysis, ANOVA. The image of gathered skirts was composed of the five factors of activities, attraction, grace, softness, and ordinary and it was showed that these five factors occupied 68.4% of the total variance. The shape of gathered skirts was composed of the two factors of the side and the front, and it was showed that these two factors occupied 93.6% of the total variance. According to correlation analysis of visual shape, the front was significant in activities, attraction and ordinary, and the side was significant in activities, grace and ordinary. As a result of ANOVA, the visual images were significant in ratio of gathers. 2.5 ratio of gathered skirts were perceived to be more active and attractive, and 1.5 ratio of gathered skirts were more ordinary and graceful.

• 복식문화연구
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• 제14권2호
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• pp.286-298
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• 2006

The purpose of this study is to find the proper width of fabric which can bring high efficiency on productivity. We focus on the marking method by comparing and analyzing the marking efficiency of flare skirt. This study employs 4 criteria to mark the flare skirt, which are angle, location, width, and direction, respectively. There can be 3 different angles$(180^{\circ},\;270^{\circ},\;360^{\circ})$, and 2 different locations(the center line and the middle of the pattern) according to fixing of the warp line of the fabric. Also, width can be classified into 2 groups(110cm, 150cm), and marking direction can be grouped into 2(one direction marker and one direction per each size marker). These 4 criteria make $24(3{\times}2{\times}2{\times}2)$ cases for this study. Main findings are follows. Fist, the skirt with the 150cm width has higher efficiency rate than that of 110cm. Second, fixing the warp line at the center line has higher efficiency rate than that in the middle. Finally, per size marker has much higher efficiency than the just direction marker. In sum, we find that 150cm width with the center warp line and per size marker brings the highest efficiency rate.

• 한국의류학회지
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• 제13권4호
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• pp.388-399
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• 1989

The purpose of this study was to investigate the effects of garment design, fabric type and the presence of lining on the thermal insulation value $(I_{cle}\;and\;I{cl})$ and clothing area factor $(f_{cl})$ of skirts. A standing, electrically heated thermal maninkin was used to measure the insultation value of eighty skirts-five skirt styles with eight different fabrics, with and without lining. The air temperature of the chamber was set at $22.2^{\circ}C{\pm}0.5^{\circ}C$ , air velocity was limited to less than 0.1 m/s, and relative humidity was approximately $50\%$. The results are as follows: 1) The Ic, values of gathered skirt and flared skirt, which had high $f_{cl}$ values, were significantly higher than those of other skirts, though the highest $I_{cle}$ value among five styles wer pegged skirt. 2) Insulation values of various skirts were more relevant with physical properties such as thickness, air permeability, and thermal transmission of the materials rather than fiber content. 3) The addition of lining made significant difference in the insulation values of skirts and the differences of gathered and flared skirt were significantly higher than those of othere types of skirts.

• 한국의상디자인학회지
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• 제8권1호
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• pp.69-79
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• 2006

The purpose of this study is to find the proper width of fabric which can bring high efficiency on productivity. We focus on the marking method by comparing and analyzing the marking efficiency of A-line skirt. This study employs 4 criteria to mark the A-line skirt, which are cutting method, angle, width, and direction, respectively. There can be 2 different cutting methods(fold pattern and add seam pattern at the front and back center line), and 2 different angles(warp angle and bias angle). Also, width of the fabric can be classified into 2 groups(110cm, 150cm), and marking direction can be grouped into 2(one direction marker and one direction per each size marker). These 4 criteria make 16($2^*2^*2^*2$) cases for this study. Main findings are follows. First, the skirt with folded at the center line had higher efficiency rate than the skirt with add seam at the center line. Second, the skirt with the 150cm width has higher efficiency rate than that of 110cm. Third, fixing the warp angle has higher efficiency rate than that of fixing the bias angle at the front and back center line. Finally, one direction per each size marker has much higher efficiency than the one direction marker.