• Title/Summary/Keyword: quality of contact

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Magnetic Levitated Electric Monorail System for Flat Panel Display Glass Delivery Applications (FPD 공정용 Glass 이송 시스템을 위한 자기부상 EMS의 개발)

  • Lee, Ki-Chang;Moon, Ji-Woo;Koo, Dae-Hyun;Lee, Min-Cheol
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.6
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    • pp.566-572
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    • 2011
  • In recent semiconductor and FPD (Flat Panel Display) manufacturing processes, high clean-class delivery operation is required more and more for short working time and better product quality. Traditionally SLIM (Single-sided Linear Induction Motor) is widely used in the liner drive applications because of its simplicity in the rail structure. A magnetically levitated (Maglev) unmanned vehicle with SLIM traction, which is powered by a CPS (Contactless Power Supply) can be a high precision delivery solution for this industry. In this paper unmanned FPD-carrying vehicle, which can levitate without contacting the rail structure, is suggested for high clean-class FPD delivery applications. It can be more acceptable for the complex facilities composed with many processes which require longer rails, because of simple rail structure. The test setup consists of a test vehicle and a rounded rail, in which the vehicle can load and unload products at arbitrary position commanded through wireless communications of host computer. The experimental results show that the suggested vehicle and rail have reasonable traction servo and robust electromagnetic suspensions without any contact. The resolution of point servo errors in the SLIM traction system is accomplished under 1mm. The maximum gap error is ${\pm}0.25mm$ with nominal air gap length of 4.0mm in the electromagnetic suspensions. This type of automated delivery vehicle is expected to have significant role in the clean delivery like FPD glass delivery.

Molybdenum Oxides as Diffusion Barrier Layers against MoSe2 Formation in A Nonvacuum Process for CuInSe2 Solar Cells (비진공법 CuInSe2 태양전지에서 MoSe2의 생성을 억제하기 위한 산화 몰리브데늄 확산장벽 층)

  • Lee, Byung-Seok;Lee, Doh-Kwon
    • Current Photovoltaic Research
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    • v.3 no.3
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    • pp.85-90
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    • 2015
  • Two-step processes for preparing $Cu(In,Ga)Se_2$ absorber layers consist of precursor layer formation and subsequent annealing in a Se-containing atmosphere. Among the various deposition methods for precursor layer, the nonvacuum (wet) processes have been spotlighted as alternatives to vacuum-based methods due to their potential to realize low-cost, scalable PV devices. However, due to its porous nature, the precursor layer deposited on Mo substrate by nonvacuum methods often suffers from thick $MoSe_2$ formation during selenization under a high Se vapor pressure. On the contrary, selenization under a low Se pressure to avoid $MoSe_2$ formation typically leads to low crystal quality of absorber films. Although TiN has been reported as a diffusion barrier against Se, the additional sputtering to deposit TiN layer may induce the complexity of fabrication process and nullify the advantages of nonvacuum deposition of absorber film. In this work, Mo oxide layers via thermal oxidation of Mo substrate have been explored as an alternative diffusion barrier. The morphology and phase evolution was examined as a function of oxidation temperature. The resulting Mo/Mo oxides double layers were employed as a back contact electrode for $CuInSe_2$ solar cells and were found to effectively suppress the formation of $MoSe_2$ layer.

A Study on the Nonwet Defective Factors of the SMT Process (SMT 공정 Nonwet 불량 인자에 대한 연구)

  • Yun, Chanhyung
    • Journal of the Microelectronics and Packaging Society
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    • v.27 no.3
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    • pp.35-39
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    • 2020
  • Nonwet (Head in Pillow) defect is one of the defects in SMT (surface mount technology) process, the defect is caused by several factors, such as solder paste misalignment, reflow condition, package warpage and package ball size. This paper focused on ① reflow condition ② package ball & solder paste misalignment ③ package ball size for nonwet experiment. The first, on the case of reflow condition, there would be high risk of nonwet defect when the soldering time was increased, but N2 was adopted to reflow process, there could be no or low risk of nonwet defect because of oxidation barrier control. And when the contact depth between Solder ball and solder paste was below 20 ㎛, there could be high risk of nonwet defect. Also smaller package ball would have low risk of nonwet defect.

Application of Sand Mat Substitutel using Steel Slag (제강슬래그를 이용한 샌드매트 대체재료의 적용성 연구)

  • Park, Jong-Beom;Lee, Byung-Chan;Ju, Jae-Woo;Na, Hyun-Ho
    • Journal of the Korean Geosynthetics Society
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    • v.11 no.1
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    • pp.57-63
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    • 2012
  • Steel slag has the nature to hydrate and expand when in contact with non-reacting CaO and water, and thus can be used only in limited scope for landfill disposal as well as for recycling as civil construction aggregates. In order to use such steel slags more efficiently, the applicability of steel slag as sand mat alternative material was reviewed. In general, sand mat is used in soft ground surface reinforcement method and horizontal drain method, and is installed simultaneously with soft ground vertical drain method. Therefore in this study steel slag designing method and application standard etc were examined to recycle steel slag as sand mat alternative material, and laboratory soil test and model test were done. Test results indicated that the designing method and application standard meet various environment and quality standards, meaning that steel slag can be utilized as sand mat alternative material, and analysis of slag mat bearing capacity also indicated that use of steel slag produces double or more bearing capacity compared with existing sand mat.

유대지불(乳代支弗) 체계(體系)와 품질관리(品質管理)를 위(爲)한 우유(牛乳) 투명화(透明化) 기술개발(技術開發)

  • Lee, Bu-Ung;Jang, Un-Gi;Heo, Mun-Yeong;In, Yeong-Min;Kim, Dong-Un;Jeong, Seok-Geun;Ham, Jun-Sang
    • 한국유가공학회:학술대회논문집
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    • 2001.05a
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    • pp.15-23
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    • 2001
  • It is very interest to use transparent milk for various determination because milk emulsion or colloidal state bring out opacity. The fat globule can disperse by butanone and casein complex can also disintergrate to monomer by action of Triton with aide of SDS and NaOH in same milk phase at time because it can be possible that butanone have amphiphilic characteristic solvent also miscible. Our formulution of solvent can treat almost all type of milk products except with proportion of Triton/Butanone such as 8:2 and 9:1 . In spite of growth inhibition to contact with solvent it call be use also for microbial counting because this formulution did not attactk wall. This is why present technique can be applied to diver determination for the reason of milk payment system, quality control, and national planning or control of national dairy.

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Development of a Pulley-type Tensioning Device (도르래식 장력조정장치 개발)

  • Lee, Ki-Won;Cho, Yong-Hyeon;Park, Young
    • Journal of the Korean Society for Railway
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    • v.12 no.5
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    • pp.663-669
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    • 2009
  • In the electrical railway, the increase of tensions in an overhead contact lines is essential to speed-up of train, because current collection quality largely depends on the ratio of a wave propagation speed to a train speed. For Kyungbu high-speed line, a pulley-type tensioning device is required to have a tension variation of maximum 3%. Therefore we developed a pulley-type tensioning device in order to meet tension variation requirement of the high-speed tensioning device. To verify the performance of the developed device, a performance test, overload test and failure test were carried out according to the factory test procedure of the Kyung-Bu High-speed line. Furthermore, we also performed reliability performance through not only a fatigue test in a factory, but also on-line verification test in Chungbuk line for over 1 year. These tests verified that the tensioning device had applicability to a main line.

A Study on the Evaluation Method of Lap Shear Strength for Induction Welding of Thermoplastic Composites using Tensile Test (인장 시험을 이용한 열가소성 복합재료 유도용접 전단강도 평가방법에 대한 고찰)

  • Baek, Inseok;Lee, Seoksoon
    • Journal of Aerospace System Engineering
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    • v.16 no.1
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    • pp.12-16
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    • 2022
  • Currently, Induction welding is attracting attention as a non-contact, clean and fast welding process. However, since thermoplastic resins are not affected by electromagnetic fields, induction welding requires a heating element called a susceptor. Researches are being conducted with the aim of achieving high-quality bonding, however, the factor of a heating element is an issue, hence the need to set a standard. Specimen fabrication and testing are conducted according to ASTM D5868. In this study, we propose that the evaluation criteria be judged on the basis of three factors; the condition of the welded joint surface, void content, and lap shear strength. Since the adhesive surface to be welded melts and solidifies as it cools, rapid temperature changes can generate pores. In addition, if the heating is not uniform, it is difficult to expect the desire performance. Using PA6 (CF 30%) thermoplastic, susceptor fabrication, induction welding and performance verification were conducted.

Full mouth rehabilitation on the patient with maxillary anterior diastema and posterior bite collapse with orthodontic treatment (상악 전치부 치간 이개와 구치부 교합지지 상실을 가진 환자에서 교정치료를 동반한 완전 구강회복 증례)

  • Lee, Seon-Ki
    • Journal of Dental Rehabilitation and Applied Science
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    • v.38 no.1
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    • pp.60-68
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    • 2022
  • A patient with severe periodontitis has causative factors that cause pathological tooth movement, the occlusion is disintegrated, and the vicious cycle of worsening periodontitis is repeated. In particular, when pathological tooth movement occurs in the maxillary anterior region, the patient has an aesthetic sense of atrophy, and the quality of life was reduced. Therefore, when orthodontic treatment was added to patients with severe periodontitis, it promotes the formation of new bone, reduces periodontal cysts, and obtains clinical attachment, which leads to favorable results in prosthetic restoration, thereby enabling ideal occlusion, function and aesthetics. Periodontal treatment, orthodontic treatment, natural tooth restoration, and implant prosthesis were planned for patients with pathological tooth movement in the anterior region due to loss of occlusal support in the posterior region. As a result, an ideal restoration space was secured, a stable restoration of occlusal contact was formed, and the maxillary anterior teeth were aesthetically improved.

Developments of Advanced Connection Type for Improvements of Mixed Structures (II) (혼합구조의 성능 향상을 위한 개선된 접합부의 개발 (II): 개선된 접합방식의 성능확인을 위한 모형실험 및 해석)

  • Yun, Ik Jung;Lho, Byeong Cheol;Kim, Moon Kyum;Cho, Sung Young
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.2A
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    • pp.207-214
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    • 2008
  • This study presents a way to validate the quality level of the proposed connection type and verify the experimental test, and performs a 3D nonlinear analysis corresponding to the experimental test. Two mixed-structure beams were cast and tested under a four-point static loading. Force-displacement relation, force-strain relation, force-opening width, and failure mode were observed from comparing the numerical results of the adopted FE model. Nonlinear analysis of mixed structures was carried out by utilizing the contact elements of a general purpose structural analysis computer program (ABAQUS). The results of numerical and experimental simulation show that the proposed L-shaped connection has greater stiffness under flexural loading and better structural performance with regard to the connection.

Breast Cancer Survival at a Leading Cancer Centre in Malaysia

  • Abdullah, Matin Mellor;Mohamed, Ahmad Kamal;Foo, Yoke Ching;Lee, Catherine May Ling;Chua, Chin Teong;Wu, Chin Huei;Hoo, LP;Lim, Teck Onn;Yen, Sze Whey
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.18
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    • pp.8513-8517
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    • 2016
  • Background: GLOBOCAN12 recently reported high cancer mortality in Malaysia suggesting its cancer health services are under-performing. Cancer survival is a key index of the overall effectiveness of health services in the management of patients. This report focuses on Subang Jaya Medical Centre (SJMC) care performance as measured by patient survival outcome for up to 5 years. Materials and Methods: All women with breast cancer treated at SJMC between 2008 and 2012 were enrolled for this observational cohort study. Mortality outcome was ascertained through record linkage with national death register, linkage with hospital registration system and finally through direct contact by phone or home visits. Results: A total of 675 patients treated between 2008 and 2012 were included in the present survival analysis, 65% with early breast cancer, 20% with locally advanced breast cancer (LABC) and 4% with metastatic breast cancer (MBC). The overall relative survival (RS) at 5 years was 88%. RS for stage I was 100% and for stage II, III and IV disease was 95%, 69% and 36% respectively. Conclusions: SJMC is among the first hospitals in Malaysia to embark on routine measurement of the performance of its cancer care services and its results are comparable to any leading centers in developed countries.