플라스틱 기어의 피로수명 평가 및 수명 예측

정태형,강성규,하영욱 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-

Through the fatigue test of plastic gears using polyacetal polymer, this research aims at providing basic data for not only specifying operation conditions of plastic gears, but also designing dimensions of plastic gears with giving fatigue life and the estimated equation of fatigue life of plastic gears. That is, from the fatigue life curves, the estimated equation of fatigue life of plastic gears is taken out. For the estimated equation of fatigue life of plastic gears, this research provides two test methods; one is preserving non-limited temperature of tooth flank, the other is preserving limited temperature of tooth flank. As results, how the temperature of tooth flank affects the fatigue life is shown. In addition, based on the endurance limit, the essential factors of the unit load and K-factor are determined, which are needed in the design of gear by bending strength and surface durability.

PEI계 복합 재료를 이용한 탄자 운반체의 사출 성형 기술 개발에 관한 연구

정태형,이범재,하영욱,이성계 한국공작기계학회 2001 한국공작기계학회 춘계학술대회논문집 Vol.2001 No.-

This research covers the development of new technique for composite injection molding of high stiffness Sabot. An analysis of polymer resin is performed by means of making test specimen mold and doing test with accordance of ASTM test guidelines. Structural analysis and simulation of injection molding process are carried out in order not only to estimate but also to predict the characteristics of molding stresses what both product and structure of mold may have. For structural analysis software, Mold flow and LS-dyna are used and universal test machine is utilized for evaluating performance of sabot. Cases of adopting this material to sabot are not announced yet in domestic academic world. In addition to that, materials for polymer-metal mixed injection molding are imported on the whole due to deficient level of domestic technology. Therefore, this new developed injection molding technique using PEI material can make it available to ensure the technology of making mold, injection and design. Finally, this technique may be applicable to another sabot having different radius of warheads from now on.

춘천지역 도시열섬의 특성과 대기질에 미치는 영향

이종범,김용국,김태우 江原大學校 附設 環境硏究所 1994 環境硏究 Vol.11 No.-

An observational study of urban heat is1and was carried out using field data obtained during 6 day in May and August 1992 in Chunchon(Population size 180,000). Air temperature was measured at 04 points along two sampling routes by thermisters attached to cars, Both routes cover urban and rural area and across the center of urban area, Continuous observation of air sonde was performed to clarify heights of nocturnal boundary layer(NBL) at the center of urban area. Surface meteorological observations were performed at both urban and rural site. This study showed that heat island Phenomena was obvious1y observed at the urbanized area during the night time With low wind Speed. The average NBL heights extended to about 100 meters, but varied with meteorological conditions. After sunset the air temperature decreased with time at both sites and cooling rate at the urban site was Heater than the rural site. The maximum heat island intensity was 7.5°C at 21 LST May 4. Using the two meteorological data gets obtained from urban and rural sites, the air Pollutant concentration was calculated by Gaussian plume model which can obtain not only horizontal distribution of concentration but also vertical distribution. The result indicated that the concentration resulted from urban meteorological data set was lower than that from rural meteorological data set. It was also calculated that the air pollutant extended to higher level in urban meteorological data set than that in rural meteorological data set.

dSPACE 보드에 의한 적응소음제거의 실시간 시뮬레이션

정원용,이영철,김태효 慶南大學校 附設 工業技術硏究所 1999 硏究論文集 Vol.17 No.-

정보통신망의 급격한 발전으로 더욱더 정확하고 빠른 정보통신시스템이 그 어느 때보다 요구되나 통신망에 존재하는 여러 가지 소음 등으로 양질의 정보를 취득, 전송하는 것이 쉽지 않다. 본 논문에서는 dSPACE DS 1103보드와 적응소음제거(ANC) 알고리즘으로 여러 가지 소음 중 가장 일반적인 백색잡음에 오염된 음성신호로부터 원래의 깨끗한 음성신호를 실시간적으로 추출하려고 한다. 결과적으로 DS 1103보드의 실시간 처리 구현의 편리함은 탁월하게 보여졌으나, NLMS 알고리즘의 계산속도의 한계로 정확하게 소음이 제거된 원래의 음성신호 파형을 얻을 수 없었지만 어느 정도 음성의 내용을 인지 할 수 있는 수준의 신호 파형을 얻을 수 있었다. Because of the extremely fasts growing expansion of the information communication networks, the more accurate and fast information transfer between communication systems is required more than ever. It is desired to denoise in the networks to transfer and store the good qualify information. In this paper, dSPACE DS 1103 real-time DSP board is used to denoise the white noise which contaminate the original speech signal with the Adaptive Noise Cancellation (ANC) algorithm. As a results, dSPACE board is a very powerful device for the noise reduction, because of the easy processing, simple manipulation and fast implementation of the ANC system. The simulation result also give us a significant noise reduction from the contaminated speech signal with the real-time processing.

濟州在來馬의 飼育現況과 經營實態에 關한 調査硏究

정창조,강태숙 濟州大學校 1982 논문집 Vol.14 No.-

本硏究는 濟州道內에서 馬飼育을 하고 있는 28個 農家를 對象으로 飼育現況과 經營實態를 調査한 結果를 要約하면 다음과 같다. 1) 道內에서 飼育中인 馬匹數(1981年)는 1,532頭로서 舊左邑이 22.5%, 濟州市 21.4%, 朝天面이 14.8%로 全體 飼育頭數의 約 60%를 이들 3個 地城에서 飼育되여지고 있었다. 2) 濟州馬의 飼育頭數는 1960年度에는 12,077頭에서 증가되어 1966年에는 최대 19,548頭에 達한바 있으나 1967年부터는 每年 減少되여 1980年에 이르러서는 2.401頭에 불과 하였으며 이와 比例하여 道外搬出量도 減少되어 年間 600餘頭에 머물고 있었다. 3) 經營形態는 馬飼育을 專業으로 하고 있는 農家는 1農家도 없었고 馬飼育을 兼한 復合經營形態인 馬飼育과 農家形態가 全體의 39.3% (11戶)로 가장 많았고 다음이 馬飼育, 農業, 畜産形態를 갖춘 農家가 32.1%(9戶)로 나타났다. 4) 濟州馬의 飼育은 大部分의 境遇 繁殖用으로 仔馬生産 (50.0%)이였으며 그 밖에 使役(28.6%)과 趣味와 運動(17.8%)등의 順으로 되여 있었다. 5) 飼育形式은 年中放牧形態의 農家가(60.7%) 많았으며 濟州馬 飼育을 爲한 放牧地가 不足(70.0%)으로 나타났고 다음으로 生産物 販路의 困難(15.0%), 飼育管理에 따른 勞動力(10.0%) 등으로 나타나 중요한 문제점으로 笞頭되고 있었다. 6) 繁殖馬의 경우 越冬期間中 榮養水準의 극도로 악화되어 姙娠馬의 경우 流産과 허약 仔馬의 生産을 함으로서 育成率이 저하로 인한 農家所得을 떨어뜨리는 결과를 초래하고 있었다. A survey was conducted to investigate rearing and management of Juju ponies(28 farms were surveyed). The results are as follows: 1. The total number of ponies kept in Jeju do was 1,533 head and distributed; 22.5% in Guja, 21.4% in Jeju city and 14.8% in Jocheon myon, Almost 60% of the total number of ponies are kept in these three districts. 2. Total number of Jeju ponies in 1960 was 12,077 however by 1966 have reached a maximum of 19,548. From 1967 onwards number of ponies dropped steadily and by 1980 there were only 1,401. The number of ponies exported has also dropped and now only about 600 ponies are exported annually. 3. Only one farmer in the survey was solely engaged in pony reasing, 39.3% of the total farms surveyed were engaged in arable farming together with horse keeping, 32.1% were animal production + arable farming + horse keeping. 4. The main reason for pony keeping was production of foals(50%) followed by 28.6% used as draft animals and 17.8% for pleasure. 5. The majority of farms(60.7%) grazed their ponies the year round on natural pasture. Factors constraining pony keeping were a) shortage of grazing pasture(70%), b)marketing difficulties(15%)and c)shortage of labour(10%). 6. Breeding animals during the winter are generally undernourished due to the low level of nutrition. Pregnant mares are particularly affected resulting in abortion and weak foals. These conditions give little profit to the farmers.

고분자 수지를 이용한 자동차 에어컨용 압축기의 씰에 관한 연구

정태형,하영욱 한국공작기계학회 2002 한국공작기계학회 춘계학술대회논문집 Vol.2002 No.-

The existing compressor steel seal used in automotive air-conditioner has the problem of oil leakage and the deterioration in shielding performance, due to the abrasion and the corrosion of the material. A new type of polymer resin seal is studied in the research. The polymer resin seal has the characteristics of high anti-abrasiveness and anti-corrosiveness, which can overcome the defects of the steel seal. In addition, the seal needs lower manufacturing cost and is appropriate to mass production, because it is made by the injection molding method requiring no mechanical processing. The profile generation program for seal mold has been developed using the gradient method, and the molding characteristics of the seal have analyzed through the flow analysis and the warpage analysis. The program has been verified by comparing the analysis results with the measured data of the test product. The research might be said to provide the basic method to produce the polymer resin seals with various types and dimensions.

고분자 수지를 이용한 자동차 에어컨용 압축기의 씰에 관한 연구

정태형,하영욱 한국공작기계학회 2002 한국생산제조학회지 Vol.11 No.5

The existing compressor steel seal used in automotive air-conditioner has the problem of oil leakage and deterioration in shielding performance, due to the abrasion and corrosion of the material. A new type of polymer resin seal studied in this research has the characteristics of high anti-abrasiveness and anti-corrosiveness, which can overcome the defects of the steel seal. In addition, the seal needs lower manufacturing cost and is appropriate to mass production, because it is made by the injection molding method requiring no mechanical processing. The profile generation program for seal mold has been developed using the gradient method, and the molding characteristics of the seal have analyzed through the flow analysis and the warpage analysis. The program has been verified by comparing the analysis results with the measured data of the test product. The research might be said to provide the basic method to produce the polymer resin seals with various types and dimensions.

분산 설계 환경 하에서 XML과 XSLT를 이용한 레거시 기어 설계 시스템의 확장

정태형,박승현 한국공작기계학회 2002 한국생산제조학회지 Vol.11 No.4

As computer-related technologies have been developed, legacy design systems have not appropriate for new computing environment. It is necessary that most of them are either modified or newly developed. However, these activities require quite much amount of cost and time. This paper presents a method of extending legacy design systems to the internet without any modification using XML and XSLT. We have been extended legacy systems in the two viewpoints. First, and XML document has been defined to present the input information of a legacy system which is executed on the consol environment - MS DOS, for example. Also, an XSLT document has been generated to transform an XML document to the input document of the legacy system. An XML document is transformed to the input document by XSLT processor according to the transformation rules defined in the XSLT document. This technique to generate input documents is independent to the platform type and facilitated to link legacy systems to other systems. Second, a legacy system controller has been made to control a legacy system and developed a web service to extend it and its controller. The legacy system controller operates it automatically. The web service provides its functions to other systems via internet. We have applied the developed methodologies to the legacy gear system which calculates AGMA gear rating and made AGMA gear rating web service.

마이크로프로세서를 利用한 溫度制御

權泰夏,鄭信一,禹鐘鎬 釜山水産大學校 1982 釜山水産大學 硏究報告 Vol.22 No.2

本 論文에서는 마이크로프로세서와 溫度符號化器를 利用해서 溫度를 計數的으로 制御할 수 있는 시스템을 보다 간단히 構成하였으며 上昇기울기, 維持溫度, 降下기울기에 따라 多少의 差는 있으나 制御溫度의 變化幅이 ±0.3% 以內로 比較的 良好하게 制御되었다. bit數가 많은 A/D 變換器를 使用한다면 보다 더 精密한 溫度制御가 可能할 것이다. 現在狀態로도 實驗室의 小容量 뿐 만 아니라 産業用의 大容量 電氣爐의 溫度制御에도 利用될 수 있을 것으로 본다. This paper describes the temperature control system of an electric furnace using a SDK-85 microprocessor system as a control unit. The hardware structure of the control system was very simplified by eliminating mechanical drive portions and employing electronic circuits instead. Moreover, by employing a software method in the system desired temperature on time, i.e., rising rate, maintaining temperature and time, falling rate, can be easily controlled and changed by program. Experimental results showed the successful operation with flexibility. Temperature variation was less than ±0.3% of the desired value and was more accurate on the maintaining temperature region.

후박 및 은행엽 추출물을 함유한 치약의 임상 및 미생물학적 효과에 관한 연구

김태일,염혜리,류인철,배기환,정종평 충남대학교 약학대학 의약품개발연구소 1996 藥學論文集 Vol.12 No.-

Previous studies have shown that Magnoliae cortex and Ginkgo biloba extracts were showed on the antimicrobial and anti-inflammatory action, in vitro. The purpose of this study was to evaluate on the effect of antimicrobial and anti-inflammatory activity of Magnoliae cortex and Ginkgo biloba extracts containing dentifrice in gingivitis. 70 subjects with gingivitis were divided into an experimental group which performed normal oral hygiene procedure with Magnoliae cortex and Ginkgo biloba extracts containing dentifrice and a control group which also performed normal oral hygiene procedure with the same dentifrice without the natural extracts and completed a double-blind, cross-over study. At baseline and 3 weeks, subjects were assayed for clinical study by plaque index, gingival index, pocket depth, GCF rate, and microbiological study by subgingival dental plaque bacterial morphotypes by phase contrast microscopy, total anaerobes, total aerobes, Black pigmented bacteroides, A-actionomycetemcomitans, A.viscosus, C.rectus, S.sanguis, P.gingivalis, P.intermedia by bacterial culture and immunofluorescence microscopy. After 3 weeks using their respective dentifrices, reductions in the clinical indices of subjects were similar between the experimental dentifrice group and a control dentifrice group except for statistically significant much reductions in PI, GI, and GCF rate in the experimental dentifrice group as compared to control dentifrice group. Also statistically significant reductions in the motile rods and Spirochetes were found in both experimental group to compare with control group, however statistically much reduction in total anaerobes, Black pigmented bacteroides, and P.gingivalis, P.intermedia were found in the experimental dentifrice group as compared to control dentifrice group. This results indicates that Magnoliae cortex and Ginkgo biloba extracts containing dentifrice might be useful for elimination of gingival inflammation.