• 대한치과보철학회:학술대회논문집
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• 1999.04a
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• pp.82.2-82.2
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• 1999

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.109-110
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• 2011

• Journal of Korean Dental Science
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• v.1 no.1
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• pp.22-27
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• 2008

Purpose : This study sought to evaluate the dimensional stability of the SITT (Silicone Index Tooth Tray) impression system and to determine whether providing space for wash impression material in SITT is a necessary step in obtaining accurate prostheses. Materials and methods : After mounting metal dies with shoulder and chamfer margins arbitrarily, SITT was fabricated using Blu-mousse$^{(R)}$. To test the dimensional stability of the SITT system for margin design, the shoulder margin and chamfer margin were evaluated. Furthermore, to test the effect of space for wash impression material, 0.5mm space in SITT and zero space in SITT were statistically compared. Results : 1. There was no significant difference between the group with shoulder margin and that with chamfer margin. 2. There was no significant difference between the group with 0.5mm space and that with zero space for wash impression material. Conclusions : Considering the limitations of this study, the dimensional stability of the SITT system did not interfere with the margin design. Space for the wash impression material was also unnecessary.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.8
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• pp.1302-1307
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• 2001

This study identifies the major coupling path by examining the variation of the coupled acoustic modal frequencies and modes. A 1/2-size acryl compartment model is designed and manufactured for the measurement and analysis of coupled acoustic modes. Due to acoustic coupling, a new acoustic mode appears in a low frequency range. This coupling affects only longitudinal acoustic modes of compartment. Experimental result shows that the package tray holes contribute to the coupling much more than the back seat and hole size is an important design factor to control low frequency acoustic modes in the coupled system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.909-917
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• 2007

Recently the trend of automobile industry is that IQS evaluation index against a sensitivity quality is increasing. To reduce rattle noise due to speaker sound at low frequencies, it is required the advanced investigation of a package tray panel and a door module panel. This paper optimized the design parameters of package tray panel according to the theoretical background about robust design and suggested the design guideline for resonance avoidance and the reduction of vibrational sensitivity considering the excitation frequency of woofer speaker. In addition, it is suggested the design guideline of a door module panel through the sensitivity analysis in case of the speaker excitation. Finally, the design factor analysis of the quality deviation of a mother-car will make it possible to guarantee the stable characteristics of vehicle vibration in the early stage of vehicle development. These improvements can lead to shortening the time needed to develop better vehicles.

• Journal of Radiation Protection and Research
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• v.13 no.1
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• pp.21-30
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• 1988

The 6 MV photon beam of a linear accelerator (Mevatron 67) was studied for electron contamination. The surface dose, attributable almost entirely to contamination electrons, has a linear dependence on field width for square fields and an inverse square dependence on distance from the bottom of the fixed head assembly. Build-up and surface dose measurements were taken with and without an acrylic blocking tray in place. Further measurements were made with a copper filter designed to reduce secondary electrons emitted by photon interactions with the acrylic tray. The results are discussed in relation to skin sparing effect for radiation therapy patients. To achieve the maximum skin sparing effect, the selection of the optimum SSD and TSD is needed.

• The Journal of the Korean dental association
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• v.17 no.9 s.124
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• pp.701-708
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• 1979

A series of combined impressions, alginate impressions and rubber base impression made of the lower left quadrant of one subject having a cast gold crown with six reference marks on lower let 1st molar. the combined impressions of hydrocolloid were removed from the mouth at 2.5min, after the insertion of the tray. The alginate impressions were removed from the mouth at 2min, after the insertion of the tray. The rubber base impressions were removed from the mouth at 10min. The effect on the accuracy of the combined impressions, alginate impressions and rubber base impressions was obtained following results by comparing the distances between the reference marks in indirect stone cast with the standard measurements of the cast gold crown prior to cementation. The findings through this study could be summarized as follows; 1. The accuracy of combined impression was superior to that of alginate impression, but it was inferior to that of rubber base impressions. 2. Combined impressions produced a little distortion of the mesio-distal length, alginate impressions produced the largest distortion, ut rubber base impressions produced the least distortion.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.618-622
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• 2000

This paper describes the correlation between the interior noise and the trunk wall vibration. Using the vibro-acoustic reciprocity, effect of the trunk wall vibration on the compartment noise is investigated on a medium size car. In the low frequency range, vehicle interior noise is dominated by several acoustic modes of the passenger compartment and the vibration modes of the surrounding shell parts. Especially, vibration of the trunk wall radiates sound and it is transferred through holes on the package tray into the passenger compartment. This paper experimentally reveals that sound can be well produced at some particular vibration modes of the trunk lid and it strongly influences the compartment noise through package tray holes. Contributions of the trunk walls to the interior noise are estimated by measuring the acoustic-structural transfer function, based on the vibro-acoustical reciprocity theorem.

• Journal of the Korean Society of Food Culture
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• v.14 no.5
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• pp.487-495
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• 1999

The objectives of this study were to analyze customer satisfaction by operational characteristics in business & industry foodservice operated by contracted foodservice management company. The instruments were developed by reviewing literatures on customer satisfaction and by intervewing with managers, employers and customers. A total of 1000 questionnaires were hand delivered at the ten contracted foodservice operations by designated coordinators. A total of 833 questionnaires were usable; resulting in an 83.3% response rate. Statistical data analysis was completed using the SAS 6.04 for description, T-test, ANOVA. Overall customer satisfaction score for office building foodservice was significantly higher than those for manufacturing company foodservice. As for the type of management contracts, overall customer satisfaction score for management fee contracts was significantly higher than those for profit and loss contracts. With regard to payment method, overall customer satisfaction score for meal card was higher than those for POS system. Concerning the categories of service, overall customer satisfaction for combo-tray service was higher than those for cafeteria-tray service and partially self-service. As for types of menus, the score of overall customer satisfaction was not significantly different between cafeteria menu and double choice menu.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2006.05a
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• pp.228-232
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• 2006

닭고기를 표면에 미생물 수준을 달리하여, plastic tray와 wrap으로 포장함에 따라 저장 3일에 TBARS 값이 도체의 미생물 수준이 증가할수록 $10^2\;CFU/cm^2$ 처리구 0.064, $10^3\;CFU/cm^2$, 0.079, $10^4\;CFU/cm^2$, 0.088 mgMA/kg으로 계속 증가하는 경향을 나타내었고 저장 5일에서도 비슷한 경향을 나타내었다. VBN의 변화도 도체 내 미생물 수준이 증가할수록 전체적으로 증가하는 경향을 나타내었다. 육색에서 명도(L*), 황색도(b*)는 미생물 수준에 따라 일정한 경향을 나타내지 않았다. 미생물 수준에 따른 총 세균수는 저장 3일 $10^2\;CFU/cm^2$ 처리구에서 3.34, $10^3\;CFU/cm^2$, 3.67, $10^4\;CFU/cm^2$ 3.77 log $CFU/cm^2$로 도체 미생물 수준이 증가할수록 약간씩 증가하는 경향을 나타내었다. 이러한 경향은 저장 5일에서도 비슷한 경향을 나타내었다. E. coli의 변화는 저장 3일에 $10^2\;CFU/cm^2$ 처리구에서 1.70, $10^3\;CFU/cm^2$, 1.69, $10^4\;CFU/cm^2$ 1.77 log $CFU/cm^2$으로 $10^4\;CFU/cm^2$ 처리구에서 가장 높은 증가율을 나타내었다. 저장 5일에서도 저장 3일과 비슷한 경향을 나타내었다.