• Title/Summary/Keyword: Foreign Materials

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Development of an Effective Defect Classification System for Inspection of QFN Semiconductor Packages (QFN 반도체 패키지의 외형 결함 검사를 위한 효과적인 결함 분류 시스템 개발)

  • Kim, Hyo-Jun;Lee, Jung-Seob;Joo, Hyo-Nam;Kim, Joon-Seek
    • Journal of the Institute of Convergence Signal Processing
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    • v.10 no.2
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    • pp.120-126
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    • 2009
  • There are many different types of surface defects on semiconductor Integrated Chips (IC's) caused by various factors during manufacturing process, such as cracks, foreign materials, chip-outs, chips, and voids. These defects must be detected and classified by an inspection system for productivity improvement and effective process control. Among defects, in particular, foreign materials and chips are the most difficult ones to classify accurately. A vision system composed of a carefully designed optical system and a processing algorithm is proposed to detect and classify the defects on QFN(Quad Flat No-leads) packages. The processing algorithm uses features derived from the defect's position and brightness value in the Maximum Likelihood classifier and the optical system is designed to effectively extract the features used in the classifier. In experiments we confirm that this method gives more effective result in classifying foreign materials and chips.

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Construction of 19F-13C Solid-State NMR Probe for 400MHz Wide-Bore Magnet

  • Jeong, Ji-Ho;Park, Yu-Geun;Choi, Sung-Sub;Kim, Yongae
    • Journal of the Korean Magnetic Resonance Society
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    • v.17 no.2
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    • pp.81-85
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    • 2013
  • Various fluorine-containing materials are used in electronic devices like LCD display panels and Li-ion batteries. The structural conformation of fluorine in fluorinated materials is an important contributing factor that influences the chemical and physical properties. The conformation can be changed by heat and stress during manufacture or use. Understanding the conformational changes is critical for understanding the performance and durability of electronic devices. Solid-state NMR spectroscopy could be widely used for the analysis of various fluorine-containing materials for electronic devices. However, conventional CPMAS probes cannot be used for in-situ analysis of fluorine-containing electronic devices like LCD panels and Li-ion batteries. In this paper, we show the design, construction, and optimization of a $^{19}F-^{13}C$ double-resonance solid-state NMR probe for a 400MHz wide-bore magnet with a flat square coil for in-situ analysis of fluorine-containing electronic devices without observing fluorine background signals. This custom-built probe does not show any fluorine background signals, and can have higher efficiency for lossy samples.

A Study on Domestic and Foreign Children's Secondary Materials (국내외 어린이 관련 이차자료에 관한 연구)

  • Lee, Lan-Ju
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.20 no.4
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    • pp.17-29
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    • 2009
  • This study investigated secondary materials of children and young adults materials produced by domestic and foreign countries. In order to do that, characteristics and present states of bibliographies, indexes, union catalogs, major journals were examined while bibliography, index and catalog were defined. This study results showed that there were no bibliography and index for children and young adults materials but only recommended book catalogs and award book catalogs were produced in Korea. There were however many various second materials in foreign countries.

Colorectal Foreign Bodies: Six Cases Report and Review of the Literature (직장을 통해 들어간 대장과 직장의 이물: 증례보고)

  • Kim, Hyoungran;Choi, Seokho;Yun, Jeongseok
    • Journal of Trauma and Injury
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    • v.28 no.1
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    • pp.51-54
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    • 2015
  • The incidence of foreign body insertion in the anorectum is rare, however, it is increasing, especially in urban populations. Foreign objects in the anorectum can be of different sizes, shapes and materials. Frangible objects like glass or beakers, and sharp foreign bodies that may easily injure the bowel mucosa are particularly dangerous. Physicians have to consider more innovative options on how to extract these foreign bodies without inciting injury; and, if injury would occur, consider different techniques to repair it, whether transanally or transabdominally, and opt for primary repair, or resection with either anastomosis or stoma creation. Here, I introduce our cases with colorectal foreign bodies and present several literatures to help physicians decide when presented with cases like these.

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Detection of different foreign bodies in the maxillofacial region with spiral computed tomography and cone-beam computed tomography: An in vitro study

  • Abolvardi, Masoud;Akhlaghian, Marzieh;Shishvan, Hadi Hamidi;Dastan, Farivar
    • Imaging Science in Dentistry
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    • v.50 no.4
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    • pp.291-298
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    • 2020
  • Purpose: The detection and exact localization of penetrating foreign bodies are crucial for the appropriate management of patients with dentoalveolar trauma. This study compared the efficacy of cone-beam computed tomography (CBCT) and spiral computed tomography (CT) scans for the detection of different foreign bodies composed of 5 frequently encountered materials in 2 sizes. The effect of the location of the foreign bodies on their visibility was also analyzed. Materials and Methods: In this in vitro study, metal, tooth, stone, glass, and plastic particles measuring 1×1×1 mm and 2×2×2 mm were prepared. They were implanted in a sheep's head in the tongue muscle, nasal cavity, and at the interface of the mandibular cortex and soft tissue. CBCT and spiral CT scans were taken and the visibility of foreign bodies was scored by 4 skilled maxillofacial radiologists who were blinded to the location and number of foreign bodies. Results: CT and CBCT were equally accurate in visualizing metal, stone, and tooth particles of both sizes. However, CBCT was better for detecting glass particles in the periosteum. Although both imaging modalities visualized plastic particles poorly, CT was slightly better for detecting plastic particles, especially the smaller ones. Conclusion: Considering the lower patient radiation dose and cost, CBCT can be used with almost equal accuracy as CT for detecting foreign bodies of different compositions and sizes in multiple maxillofacial regions. However, CT performed better for detecting plastic particles.

The study on the policy of systematical management of the records collected from abroad (해외소재 한국학관련 역사기록의 정보화 방안 연구)

  • Chung, Hye-Kyung;Kim, Sung-Sik
    • The Korean Journal of Archival Studies
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    • no.1
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    • pp.137-188
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    • 2000
  • Korea was highly successful in maintaining a strong tradition of record preservation. However, Japanese imperialism and the Korean war over this century has seen a huge quantity of these once plentiful records either destroyed or relocated overseas. Many of Korea records remain in the custody of foreign archival institutions. Additionally, many records of foreign states concerned with korean affairs, for example, records of the Department of state, in the U.S.A., are of great relevance to Korean modern history. These records which exist in foreign countries are a necessary and invaluable resource in the advancement of Korea studies. After the 1980s, as research interest in Korean modern history increased gradually, much historical material related to Korea was extensively introduced, removed, collected from the U.S.A., Japan, Russia and China etc. by the efforts of pioneering scholars and institutions. Several attempts at collating and publishing this material have been made. Despite this encouraging result, individual scholars and institutions's efforts face problems in relation to removal of records. Firstly, it is repeated nonproductively to remove and collect the same records, for we didn't establish a comprehensive information system, through which the condition of foreign record removal and management is able to be administrated. Secondly, there is no system for arrangement, preservation, use of removed records. For example, finding aids, such as inventory, register, description, isn't prepared for user. A user may usually not understand an accurate context of their creation, preservation removal. Thirdly, almost institution has arranged the removed records among other materials and books. Each institution has a different classification criteria, too. These conditions seem to make a difficulty in national management. This study investigated how the materials for Korea history which has been removed from foreign countries should be managed for effective preservation and use. For these purpose, we investigated the present conditions of removal and management of these materials. Also, we investigated examples of the foreign state, U.S.A. and Japan to have a idea for removal and management policy. Then, This study propose a establishment of information network system as management policy. To administrate removing and managing records effectively, an idea that records belong to the public should be accepted commonly. The policy for management of the record is followings. Firstly, unification of classification is necessary. The records which were removed from foreign countries had better to be classified according to their origins of states and institutions. Secondly, Finding aids should be prepared for user. There are many accession aids such as catalog, register, inventory for user in archives. This will be a efficient method for management. When a record is removed, a card for description of contents must be composed. Thirdly, a digital input and network system establishment is necessary. It will help to manage a condition of removed records. A digital input and management system establishment is not just a project of digitalizing records. At present, various finding aids need to be introduced to make a database for records and archives. An search using only 'search engine' may make a difficulty in finding materials because such method is apt to have too much or little result. So, classification, arrangement, description, response-service should be integrated in these system. The recent technical advancement give a opportunity to realize this idea. Above all, these procedure should be archival process.

Clinical Analysis of Upper Aerodigestive Tract Foreign Body (기도 및 식도 이물에 대한 임상적 고찰)

  • Lee, Min-Young;Jung, Sung-Do;Kim, Young-Hoon;Chung, Phil-Sang;Lee, Sang-Joon
    • Korean Journal of Bronchoesophagology
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    • v.15 no.1
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    • pp.28-34
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    • 2009
  • Background and Objectives: Foreign bodies of upper aerodigestive tract are common problem for primary care physicians. Delayed diagnosis or failure of removal might cause fatal problemsand complications. Therefore proper diagnosis and management is imperative. In this study, we described clinical features of upper aerodigestive tract foreign body, and analyzed efficacy of different management modality. Materials and Methods: 250 cases of foreign bodies in the esophagus and trachea, between Jan. 1998 through Jan. 2009 has been retrospectively analyzed. A total of 24 cases and 226 cases had been found each as airway foreign bodies and esophageal foreign bodies. The clinical features are described and treatment outcomes, prognosis, and rate of complications of each management modality have been compared. Results: In airway foreign bodies, ventilating bronchoscopy yielded better results, 19 success out of 19 trials than fiberoptic bronchoscopy, 3 success out of 5 trials. Hospitalization days after removal of foreign body didn't show difference between two treatment modalities, although patients who had ventilating bronchoscopy had gone through general anesthesia. And there was no complication after removal of foreign body. In esophageal foreign bodies, rigid esophagoscope yielded better results, 99% of successful removal rate, compared to the EGD, only 78% of successful removal rate. There was no difference of hospitalization days between two modalities. And complication rate was even low in patients who had done rigid esophagoscopic foreign body removal. Conclusion: In upper aerodigestivetract foreign body. Rapid diagnosis and successful foreign body removal is important. Removal by rigid scope(ventilating bronchoscope, rigid esophagoscope) revealed less failure in both airway and esophageal foreign bodies.

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