• 제목/요약/키워드: Thread change

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소재와 나사산 변화에 따른 정밀나사의 체결력 향상에 관한 연구 (A Study on the Clamping Improvement of Precision Screws according to the Materials and Thread Changes)

  • 황우채;나승우
    • 한국정밀공학회지
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    • 제32권6호
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    • pp.503-507
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    • 2015
  • In this study, we compare the performance of the screw through the Clamping force of the test materials to change shape and structure, one of the ways to maintain and improve the engaging force to cope with the miniaturization of the fastener threads are further thinner and lighter precision way that can improve the fastening force of the screw results were as follows. The clamping force according to the materials was $7.57N{\cdot}cm$ in SUS XM7 and SWCH18A was $5.97N{\cdot}cm$. This result was to be found to average 13.5% high in the Clamping force of SUS XM7 materials. In the case of the clamping force of the screw thread shape change, the clamping force of symmetrical and asymmetrical thread was $6.78N{\cdot}cm$ and $7.57N{\cdot}cm$. The clamping force of the asymmetrical thread showed an average high of 11.6%.

봉제용 심방사와 일반 방적봉사와의 가봉성 비교연구 (A Comparative Study on Sewabilities of Core-spun and the Other Spun Sewing Threads)

  • 김진의;차옥선
    • 한국의류학회지
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    • 제9권2호
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    • pp.1-11
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    • 1985
  • The purpose of this study was to research the effect of sewing threads on sewability. The materials used in this study were cotton threads, p/c spun thread, polyester spun thread and core-spun thread, which were the same in count, but different in fibers. In order to approach the purpose of this study, the change of sew-ability was measured according to the number of laundering. The results from this measure were as follows; 1. The order of seam strength according to the sewing threads was polyester spun threads, p/c spun thread, core-spun thread, and cotton thread in proportion to the loop strength of the sewing threads. The preserving rate of strength after laundering was the highest in core spun thread. 2. The order of seam elongation according to the sewing threads was polyester spun thread, p/c spun thread, core-spun thread and cotton thread in proportion to the elongation of the sewing threads. The preserving rate of elongation after laundering was the highest in core spun thread. 3. The order of seam puckering according to the sewing threads' was core-spun thread, p/c spun thread, polyester spun thread and cotton thread. The order of changing rate after laundering was the same as the former order. 4. The order of the needle temperature according to the sewing threads was polyester spun thread, core-spun thread, p/c spun thread and cotton thread.

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Prediction-based Dynamic Thread Pool System for Massively Multi-player Online Game Server

  • Ju, Woo-Suk;Im, Choong-Jae
    • 한국멀티미디어학회논문지
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    • 제12권6호
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    • pp.876-881
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    • 2009
  • Online game servers usually has been using the static thread pool system. But this system is not fit for huge online game server because the overhead is always up-and-down. Therefore, in this paper, we suggest the new algorithm for huge online game server. This algorithm is based on the prediction-based dynamic thread pool system. But it was developed for web servers and every 0.1 seconds the system prediction the needed numbers of threads and determine the thread pool size. Some experimental results show that the check time of 0.4 seconds is the best one for online game server and if the number of worker threads do not excess or lack to the given threshold then we do not predict and keep the current state. Otherwise we apply the prediction algorithm and change the number of threads. Some experimental results shows that this proposed algorithm reduce the overhead massively and make the performance of huge online game server improved in comparison to the static thread pool system.

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An Assessment of the Deterioration of Fabricated Metal Thread with Light, and Temperature and Humidity Factors: A Focused Study of Asian Textile Collections at the Metropolitan Museum of Art, New York

  • Park, Hae Jin;Hwang, Minsun;Chung, Yong Jae
    • 보존과학회지
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    • 제34권4호
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    • pp.245-257
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    • 2018
  • To investigate the deterioration of textiles with metal thread, I surveyed 40 textile objects, dating from the 11th to the 19th century from Korea, China, Japan, and Central Asia at the Metropolitan Museum of Art, New York. This survey included various types, widths, and thicknesses of metal thread. In addition, deterioration was examined under the microscope and color information was collected using the spectrophotometer. While investigating metal thread in the collections, I fabricated 12 different types of metal samples with metal leaf(24K gold, silver, and copper leaf), adhesive (hide animal glue and a mixture of hide animal glue and iron oxide red), and paper substrate(Korean mulberry and Taiwanese kozo paper). The accelerated deterioration process of those fabricated samples was carried out using a light box(UV and daylight), and a humidity cabinet. In the light experiment with blue scales textile fading card(aka, blue wool standard), the metal leaf began to peel off during the deterioration process with 756,000 lux-hours UV and daylight. In the temperature and humidity experiment, I could observe the reddish tarnish on copper, and some part of it began to peel off. Color reading on the light exposed samples showed that the degree of color change on the surface follows the amount of exposure as it increased over time. On the other hand, color change on the samples after artificial deterioration using temperature and humidity factors showed random change of color with occasional spikes. Distortion of original shape worsened in the samples exposed to temperature and humidity.

세번수 면직물의 땀수 변화에 따른 봉합강도 (Seam Strength Depending on the Change of Stitch Density of Fine Cotton Fabrics)

  • 어미경
    • 한국의상디자인학회지
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    • 제15권2호
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    • pp.57-64
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    • 2013
  • As the clothing materials have been more functional and advanced, the cotton fabrics for dress shirts or blouses have been more qualified and the sewability for high degree of completion has been required. This study aims to identify the seam strength depending on the change of stitch density of fine cotton fabrics by fabric and thread and so the general seam performance of fine cotton fabrics by analyzing the seam efficiency and breaking mode of seams. For an experiment, 3 kinds of fine cotton fabrics and 2 kinds of threads were selected and the sample was made by changing the stitch density by four steps. Then, the seam strength was measured. Next, the seam efficiency and breaking mode of seams were analyzed on the basis of the results of seam strength measurement. The results are as follows: All fabrics showed the similar tendency in seam strength. The seam strength is related to the tensile strength and thread strength, it increased only to a certain stitch density. When the stitch density exceeded a certain level, fabrics were destroyed or threads were cut. Then, the seam strength didn't increase. Furthermore, the more the seam strength increased, the more the seam efficiency increased. For increasing the maximum stitch density, it was required to use the fabrics and threads which had similar properties, in other words, the high thread strength for the high tensile strength and the low thread strength for the high tensile strength.

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비만치료를 위한 매선요법의 중복시술 효과 5례 (The Duplicate Effect of Thread-embedding Therapy on 5 Patients with Obesity)

  • 신화영;임성철;이윤규;권효정;정태영;이봉효;김재수
    • Journal of Acupuncture Research
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    • 제29권1호
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    • pp.61-66
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    • 2012
  • Objectives : The purpose of this study was to examine the duplicate effect of thread-embedding therapy against obesity. Methods : 5 women from 20 to 30 with obesity were treated with thread-embedding therapy and compared the results with physical measurement, body composition tests and fat thickness measured by ultrasound. Results : The thread-embedding therapy locally reduced body size and fat thickness and had a cumulative effect, but showed the greatest effect in the abdominal region. It didn't affect to the overall change of body composition. Conclusions : The duplicate procedure of thread-embedding therapy for obesity had a cumulative effect, but it depended on the treatment region.

견직물의 내광성에 관한 연구 (An Experimental Study on the Lightfast of Silk Fabrics)

  • 박일록
    • 대한가정학회지
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    • 제20권1호
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    • pp.1-10
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    • 1982
  • This experiment was made on the basis of the general observation that silk fabrics is flaccid in sun light. The purpose of this test is to examine efficiency between the processed thread and the unprocessed one after putting the later under the xenon-lit system, which produces continuous spectrum of bright white beam similar to sun light. (i) Color division of silk thread : white, yellow blue (ii) light division and irradiation time : sun lightlongrightarrow210 hrs, Xenonlongrightarrow50,100, 150 hrs. Under the above conditions each object was be tested with and extensometer, TENSILON Type III for the results of (a) the weight-expansibility curve of the silk thread (b) the relationship between cutting in tensity and maximum, weight (c) maximum expansion rate (d) the expansion energy of the tested silk thread (e) the beginning pull-stretch resistance rate of the tested silk thread (f) color difference after processing The results are illustrated in the appropriate tables and figures. Consequently the generalobservation that silk fabrics is flaccid is relevant only in terms of color. So for as Cutting-intensaty is concerned, it turned out to be less flaccid than in color. On the contrary when the untested silk thread was conpared with the xenon-irradiated ones, the latter proved itself to be more flaccid in cutting expansibility than the former. We have learned through this experiment that, after the all rounds of this test, the color tone and chroma of the colored materials remained without significant change, where as their color value changed to a large extent.

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Ti-6Al-4V 티타늄 합금나사의 절삭 특성 (Machining Characteristics of Ti-6Al-4V Thread)

  • 김형선;최종근;김동민;류민영
    • 한국생산제조학회지
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    • 제18권5호
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    • pp.514-520
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    • 2009
  • Titanium is one of the most attractive materials due to their superior properties of high specific strength and excellent corrosion resistance. The applications in aerospace and medical industries demand machining process more frequently to obtain more precise products. Machining of titanium is faced with strong challenges such as increased component complexity i.e. airframe components manufacturing processes. The machining cost on titanium have traditionally demanded high cutting tool consumable cost and slow machining cycle times. Similarly, the high wear of the cutting tools restricts the cutting process capabilities. Titanium screws applied to fasten parts In the several corrosion environment. In the thread cutting of titanium alloys, the key point for successful work is to select proper cutting methods and tool materials. This study suggests a guidance fur selecting the cutting methods and the tool materials to improve thread quality and productivity. Some experiments investigate surface roughnesses, cutting forces and tool wear with change of various cutting parameters including tool materials, cutting methods, cutting speed. As the results, the P10 type insert tip was assured of the best for thread cutting of Ti-6Al-4V titanium alloy. Also the initial depth of infeed was desirable to use the value below 0.5mm as the uniform cutting area method is applied.

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벨 마비 급성기에 대한 매선요법 병행치료의 임상적 효과 (Effectiveness of Thread-embedding Therapy Combined with Korean Medicine Treatment on Acute phase of Bell's Palsy)

  • 이유정;최연아;김태준;노정두
    • 한방안이비인후피부과학회지
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    • 제34권1호
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    • pp.1-12
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    • 2021
  • Objectives : This study was to investigate the effectiveness of thread-embedding therapy for the treatment of acute phase of Bell's palsy. Methods : Thread-embedding therapy was performed once a week on 29 patients within 1 weeks after the onset. We investigated the general characters, Yanagihara's score, House-Brackmann scale and FDI were used to evaluate the effectiveness of thread-embedding therapy. Results : Facial muscle recovery began at 13.37th day, that was about 0.36 day earlier than the previous patients who were treated without thread-embedding therapy in 2017 at the same hospital, but there was no statistical significance. In the change of each scale before and after treatment, Yanagihara's score, House-Brackmann scale, physical function and social function of FDI were changed significantly. Compared with the patients treated without thread-embedding therapy in 2017, Yanagihara's score was a little higher and House-Brackmann scale was a little lower. Conclusions : These findings suggested that thread-embedding therapy on acute phase of Bell's palsy was a little more effective than the conventional therapy without thread-embedding therapy.

GraalVM 및 Virtual Thread 환경에서 API Gateway의 성능 평가 (Performance evaluation of API Gateway in GraalVM and Virtual Thread environment)

  • 조동일
    • 인터넷정보학회논문지
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    • 제25권4호
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    • pp.39-46
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    • 2024
  • API 게이트웨이는 클라우드 외부의 API 클라이언트가 클라우드 내부 서비스와 통신할 수 있는 단일 진입점을 제공하는 고가용성 구성요소로서 병목 현상을 발생시킬 위험이 크고 서비스 변경 시 재배포가 필요하다. 여러 API 게이트웨이가 구현되고 있는 Java 언어는 배포와 운영 성능의 문제를 극복하기 위해 GraalVM Native Image와 Virtual Thread라는 기술을 발표하였다. Java 애플리케이션에 이들 기술을 적용하기 위해서는 소스 코드 및 배포 절차를 변경해야 한다. 본 연구에서는 API 게이트웨이가 GraalVM Native Image와 Java Virtual Machine(JVM) 기반으로 동작했을 때와 Virtual Thread와 Reactive 스레드 처리 방식 간의 성능을 측정하고 분석하였다. 본 연구에서는 배포 성능과 운영 성능의 평가를 위해 평가지표를 선정하였고 네 가지 환경에서 평가지표의 성능을 측정하고 평가하였다.