• Title/Summary/Keyword: cause of defects

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Fabrication of implant-associated obturator after extraction of abutment teeth: a case report (지대치 발거 후 임플란트 연관 상악 폐색장치 제작 증례보고)

  • Ki-Yeol Jang;Gyeong-Je Lee
    • Journal of Dental Rehabilitation and Applied Science
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    • v.39 no.4
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    • pp.229-236
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    • 2023
  • Maxillary bone defects may follow surgical treatment of benign and malignant tumors, trauma, and infection. Palatal defects often lead to problems with swallowing and pronunciation from the leakage of air into the nasal cavity and sinus. Obturators have been commonly used to solve these problems, but long-term use of the device may cause irritation of the oral mucosa or damage to the abutment teeth. Utilizing implants in the edentulous area for the fabrication of the obturators has gained attention. This case report describes a patient, who had undergone partial resection of the maxilla due to adenocarcinoma, in need of a new obturator after losing abutment teeth after long-term use of the previous obturator. Implants were placed in strategic locations, and an implant-retained maxillary obturator was fabricated, showing satisfactory results in the rehabilitation of multiple aspects, including palatal defect, masticatory function, swallowing, pronunciation, and aesthetics.

Sural Artery Flap (비복동맥 피판술)

  • Hahn, Soo-Bong;Park, Jin;Kim, Bo-Hyeon
    • Archives of Reconstructive Microsurgery
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    • v.11 no.1
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    • pp.36-40
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    • 2002
  • Purpose : Our clinical experiences in distally based sural artery island flap is presented to show the usefulness and the reliability as an alternative to flaps currently used for defect in lower extremity. Materials and Methods : From February 1998 to September 2001, nine cases of soft tissue defects in the lower leg, the foot, and around the ankle were treated with distally based sural artery island flap. The cause of the wound was trauma in 6 cases, and osteomyelitis in 3 cases. Defects were located at the lower leg in 2 cases, at the foot in 3 cases and around the ankle in 4 cases. The results were retrospectively analyzed. Results : The defect size ranged from $3{\times}3cm\;to\;20{\times}3cm$. Among 9 cases, 7 cases survived and 2 cases were failed. Flap failure was due to not including the deep fascia in one case and due to extensive soft tissue damage in the other case. Both failed cases were reoperated with the split thickness skin graft. Conclusion : The advantages of distally based sural artery island flap follows (1) reliable blood supply, (2) ease of flap elevation, (3) preservation of the major arteries, (4) less donor site morbidity. Owing to the advantages of this flap, we think it is useful for the soft tissue coverage of the lower leg, the foot and around the ankle. Also we believe it will continue to gain acceptance and use in the majority of lower leg reconstruction.

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Dislocations as native nanostructures - electronic properties

  • Reiche, Manfred;Kittler, Martin;Uebensee, Hartmut;Pippel, Eckhard;Hopfe, Sigrid
    • Advances in nano research
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    • v.2 no.1
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    • pp.1-14
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    • 2014
  • Dislocations are basic crystal defects and represent one-dimensional native nanostructures embedded in a perfect crystalline matrix. Their structure is predefined by crystal symmetry. Two-dimensional, self-organized arrays of such nanostructures are realized reproducibly using specific preparation conditions (semiconductor wafer direct bonding). This technique allows separating dislocations up to a few hundred nanometers which enables electrical measurements of only a few, or, in the ideal case, of an individual dislocation. Electrical properties of dislocations in silicon were measured using MOSFETs as test structures. It is shown that an increase of the drain current results for nMOSFETs which is caused by a high concentration of electrons on dislocations in p-type material. The number of electrons on a dislocation is estimated from device simulations. This leads to the conclusion that metallic-like conduction exists along dislocations in this material caused by a one-dimensional carrier confinement. On the other hand, measurements of pMOSFETs prepared in n-type silicon proved the dominant transport of holes along dislocations. The experimentally measured increase of the drain current, however, is here not only caused by an higher hole concentration on these defects but also by an increasing hole mobility along dislocations. All the data proved for the first time the ambipolar behavior of dislocations in silicon. Dislocations in p-type Si form efficient one-dimensional channels for electrons, while dislocations in n-type material cause one-dimensional channels for holes.

Texture Analysis Algorithm and its Application to Leather Automatic Classification Inspection System (텍스처 분석 알고리즘과 피혁 자동 선별 시스템에의 응용)

  • 김명재;이명수;권장우;김광섭;길경석
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2001.10a
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    • pp.363-366
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    • 2001
  • The present process of grading leather quality by the rare eyes is not reliable. Because inconsistency of grading due to eyes strain for long time can cause incorrect result of grading. Therefore it is necessary to automate the process of grading quality of leather based on objective standard for it. In this paper, leather automatic classification system consists of the process obtaining the information of leather and the process grading the quality of leather from the information. Leather is graded by its information such as texture density, types and distribution of defects. This paper proposes the algorithm which sorts out leather information like texture density and defects from the gray-level images obtained by digital camera. The density information is sorted out by the distribution value of Fourier spectrum which comes out after original image is converted to the image in frequency domain. And the defect information is obtained by the statistics of pixels which is relevant to Window using searching Window after sort out boundary lines from preprocessed images. The information for entire leather is used as standard of grading leather quality, and the proposed algorithm is practically applied to machine vision system.

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Effect of negative oxygen ion bombardment on the gate bias stability of InGaZnO

  • Lee, Dong-Hyeok;Kim, Gyeong-Deok;Hong, Mun-Pyo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.160-160
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    • 2015
  • InGaZnO (IGZO) thin-film transistors (TFTs) are very promising due to their potential use in high performance display backplane [1]. However, the stability of IGZO TFTs under the various stresses has been issued for the practical IGZO applications [2]. Up to now, many researchers have studied to understand the sub-gap density of states (DOS) as the root cause of instability [3]. Nomura et al. reported that these deep defects are located in the surface layer of the IGZO channel [4]. Also, Kim et al. reported that the interfacial traps can be affected by different RF-power during RF magnetron sputtering process [5]. It is well known that these trap states can influence on the performances and stabilities of IGZO TFTs. Nevertheless, it has not been reported how these defect states are created during conventional RF magnetron sputtering. In general, during conventional RF magnetron sputtering process, negative oxygen ions (NOI) can be generated by electron attachment in oxygen atom near target surface and accelerated up to few hundreds eV by self-bias of RF magnetron sputter; the high energy bombardment of NOIs generates bulk defects in oxide thin films [6-10] and can change the defect states of IGZO thin film. In this study, we have confirmed that the NOIs accelerated by the self-bias were one of the dominant causes of instability in IGZO TFTs when the channel layer was deposited by conventional RF magnetron sputtering system. Finally, we will introduce our novel technology named as Magnetic Field Shielded Sputtering (MFSS) process [9-10] to eliminate the NOI bombardment effects and present how much to be improved the instability of IGZO TFTs by this new deposition method.

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A Tie-Over Dressing Using a Silicone Tube to Graft Deep Wounds

  • Bektas, Cem Inan;Kankaya, Yuksel;Ozer, Kadri;Baris, Ruser;Aslan, Ozlem Colak;Kocer, Ugur
    • Archives of Plastic Surgery
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    • v.40 no.6
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    • pp.711-714
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    • 2013
  • Background The most common cause of skin graft failure is the collection of blood or serous fluid underneath the graft. In our study, we describe the use of silicone tube for tie-over dressing to secure the skin graft margins with the aim of decreasing loss of the skin graft, particularly in grafting of deep wounds. Methods Between March 2008 and July 2011, we used this technique in 17 patients with skin defects with depths ranging from 3.5 to 8 mm (mean, 5.5 mm). First, the skin graft was sutured with 3/0 silk suture material from its corners. Then, a silicone round drain tube was sutured with 3/0 absorbable polyglactin 910 over the margins of the graft. Finally, long silk threads were tied over the bolus dressing, and the tie-over dressing was completed in the usual fashion. Results The mean follow-up was 7 months (range, 2-10 months) in the outpatient clinic. Graft loss on the graft margins due to hematoma or seroma was not developed. The results of adhesion between the graft and wound bed peripherally was excellent. Conclusions In our study, we suggest that use of a silicone tube for additional pressure on the edges of skin grafts in case of reconstruction of deep skin defects.

Bone Regenerative Effects of Biphasic Calcium Phosphate Collagen, Bone Morphogenetic Protein 2, Mesenchymal Stem Cells, and Platelet-Rich Plasma in an Equine Bone Defect Model

  • Eun-bee Lee;Hyunjung Park;Jong-pil Seo
    • Journal of Veterinary Clinics
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    • v.40 no.2
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    • pp.85-92
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    • 2023
  • Fractures in the horse industry are challenging and a common cause of death in racehorses. To accelerate fracture healing, tissue engineering (TE) provides promising ways to regenerate bone tissues. This study aimed to evaluate the osteogenic effects of biphasic calcium phosphate collagen (BCPC) graft, bone morphogenetic protein 2 (BMP2), mesenchymal stem cell (MSC), and platelet-rich plasma (PRP) treatments in horses. Four thoroughbred horses were included in the study, and, in each horse, three cortical defects with a diameter of 5 mm and depth of 10 mm were formed in the third metacarpal bones (MC) and metatarsal bones (MT). The defects were randomly assigned to one of six treatment groups (saline, BCPC, BMP2, MSC, PRP, and control). Injections of saline, BMP2, PRP, or MSCs were made at 1, 3, and 5 weeks after defect surgery. Bone regeneration effects were assessed by radiography, quantitative computed tomography (QCT), micro-computed tomography (μCT), histopathological, and histomorphometric evaluation. The new bone ratio (%) in the histomorphometric evaluation was higher in the BMP2 group than in the control and saline groups. Radiographic and QCT values were significantly higher in the BCPC groups than in the other groups. QCT values of the BMP2 group were significantly higher than in the control and saline groups. The present study demonstrated that BCPC grafts were biologically safe and showed osteoconductivity in horses and the repeated injections of BMP2 without a carrier can be simple and promising TE factors for treating horses with bone fractures.

Design and Implementation of an Automated Visual Inspection System of PDP Frames (PDP 프레임 자동시각검사 시스템 설계 및 구현)

  • Park, Byung-Joon;Hahn, Kwang-Soo;Shin, Eun-Seok
    • Journal of Korea Multimedia Society
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    • v.13 no.4
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    • pp.512-525
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    • 2010
  • A PDP(Plasma Display Panel) Frame is critical part of PDP and also produces couple hundred thousand every month. In the process of mass production, product inspection is very important process. Also to increase the reliance, inspection each part and every final product is asked quite often. Purpose of this paper is to use computer vision system to inspect the PDP parts which is Automated visual process inspection. This paper contains the system design for inspecting defects of hole, tab, stud, rivet of PDP Frame. The system also can inspect various kinds of PDP frames. Quick and accurate 100% inspection of all shapes can improve the manufacturing productivity. Inspection results can be stored in a database and analyzed to find the cause of defects. After applying the system to the industry, the result shows the possibility of fast and accuracy of the inspection.

Effect of Negative Oxygen Ions Accelerated by Self-bias on Amorphous InGaZnO Thin Film Transistors

  • Kim, Du-Hyeon;Yun, Su-Bok;Hong, Mun-Pyo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.466-468
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    • 2012
  • Amorphous InGaZnO (${\alpha}$-IGZO) thin-film transistors (TFTs) are are very promising due to their potential use in thin film electronics and display drivers [1]. However, the stability of AOS-TFTs under the various stresses has been issued for the practical AOSs applications [2]. Up to now, many researchers have studied to understand the sub-gap density of states (DOS) as the root cause of instability [3]. Nomura et al. reported that these deep defects are located in the surface layer of the ${\alpha}$-IGZO channel [4]. Also, Kim et al. reported that the interfacial traps can be affected by different RF-power during RF magnetron sputtering process [5]. It is well known that these trap states can influence on the performances and stabilities of ${\alpha}$-IGZO TFTs. Nevertheless, it has not been reported how these defect states are created during conventional RF magnetron sputtering. In general, during conventional RF magnetron sputtering process, negative oxygen ions (NOI) can be generated by electron attachment in oxygen atom near target surface and accelerated up to few hundreds eV by self-bias of RF magnetron sputter; the high energy bombardment of NOIs generates bulk defects in oxide thin films [6-10] and can change the defect states of ${\alpha}$-IGZO thin film. In this paper, we have confirmed that the NOIs accelerated by the self-bias were one of the dominant causes of instability in ${\alpha}$-IGZO TFTs when the channel layer was deposited by conventional RF magnetron sputtering system. Finally, we will introduce our novel technology named as Magnetic Field Shielded Sputtering (MFSS) process [9-10] to eliminate the NOI bombardment effects and present how much to be improved the instability of ${\alpha}$-IGZO TFTs by this new deposition method.

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Improving Compiler to Prevent Buffer Overflow Attack (버퍼오버플로우 공격 방지를 위한 컴파일러 기법)

  • Kim, Jong-Ewi;Lee, Seong-Uck;Hong, Man-Pyo
    • The KIPS Transactions:PartC
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    • v.9C no.4
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    • pp.453-458
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    • 2002
  • Recently, the number of hacking, that use buffer overflow vulnerabilities, are increasing. Although the buffer overflow Problem has been known for a long time, for the following reasons, it continuos to present a serious security threat. There are three defense method of buffer overflow attack. First, allow overwrite but do not allow unauthorized change of control flow. Second, do not allow overwriting at all. Third, allow change of control flow, but prevents execution of injected code. This paper is for allowing overwrites but do not allow unauthorized change of control flow which is the solution of extending compiler. The previous defense method has two defects. First, a program company with overhead because it do much thing before than applying for the method In execution of process. Second, each time function returns, it store return address in reserved memory created by compiler. This cause waste of memory too much. The new proposed method is to extend compiler, by processing after compiling and linking time. To complement these defects, we can reduce things to do in execution time. By processing additional steps after compile/linking time and before execution time. We can reduce overhead.