• The Journal of Advanced Prosthodontics
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• 제2권3호
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• pp.102-105
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• 2010

PURPOSE. The aims of this study were to suggest a method of fabrication of the record base using a light-polymerized resin by applying the two-phase fabrication method for the improvement of the fit of the record base and to compare the degree of fit according to the separation site. MATERIALS AND METHODS. In the edentulous cast of maxilla, four test groups were considered. In the first, second, third, and fourth test groups (n = 12 in each group) the separation was done at 0, 5, 10, and 15 mm, respectively below the alveolar crest along the palatal plane. For the control group, the record base was made without separating the two sections. The light-body silicone material was injected into the fitting surface of the record base. It was then placed onto the cast and finger pressure was applied to stabilize it in a seated position followed by immediate placement onto the universal test device. Finally, the mass of the impression material was measured after it was removed. ANOVA was performed using the SAS program. For the post-hoc test, the Wilcoxon Rank-Sum test and the Tukey-Kramer HSD test were performed ($\alpha$ = 0.05). RESULTS. The control group and Group 3, 4 showed significant differences. The Group 3 and 4 showed significantly smaller inside gaps than the control group which was not made with the two-phase fabrication method. CONCLUSION. The two-stage polymerized technique can improve the fit of the denture base particularly when the separation was made at 10 to 15 mm from the alveolar crest.

• Asian Pacific Journal of Cancer Prevention
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• 제13권5호
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• pp.1873-1875
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• 2012

Objective: To compare the complications of peripherally inserted central catheters (PICC) by a modified Seldinger technique under ultrasound guidance or the conventional (peel-away cannula) technique. Methods: From February to December of 2010, cancer patients who received PICC at the Department of Chemotherapy in Jiangsu Cancer Hospital were recruited into this study, and designated UPICC if their PICC lines were inserted under ultrasound guidance, otherwise CPICC if were performed by peel-away cannula technique. The rates of successful placement, hemorrhage around the insertion area, phlebitis, comfort of the insertion arm, infection and thrombus related to catheterization were analyzed and compared on days 1, 5 and 6 after PICC and thereafter. Results: A total of 180 cancer patients were recruited, 90 in each group. The rates of successful catheter placement between two groups differed with statistical significance (P <0.05), favoring UPICC. More phlebitis and finger swelling were detected in the CPICC group (P <0.05). From day 6 to the date the catheter was removed and thereafter, more venous thrombosis and a higher rate of discomfort of insertion arms were also observed in the CPICC group. Conclusion: Compared with CPICC, UPICC could improve the rate of successful insertion, reduce catheter related complications and increase comfort of the involved arm, thus deserving to be further investigated in randomized clinical studies.

• Clinical and Experimental Pediatrics
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• 제63권6호
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• pp.232-236
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• 2020

Background: Children today get access to smartphones at an early age. However, their ability to use mobile apps has not yet been studied in detail. Purpose: This study aimed to assess the ability of children aged 2-8 years to perform touchscreen gestures and follow prompting techniques, i.e., ways apps provide instructions on how to use them. Methods: We developed one mobile app to test the ability of children to perform various touchscreen gestures and another mobile app to test their ability to follow various prompting techniques. We used these apps in this study of 90 children in a kindergarten and a primary school in New Delhi in July 2019. We noted the touchscreen gestures that the children could perform and the most sophisticated prompting technique that they could follow. Results: Two- and 3-year-old children could not follow any prompting technique and only a minority (27%) could tap the touchscreen at an intended place. Four- to 6-year-old children could perform simple gestures like a tap and slide (57%) and follow instructions provided through animation (63%). Seven- and 8-year-old children could perform more sophisticated gestures like dragging and dropping (30%) and follow instructions provided in audio and video formats (34%). We observed a significant difference between the number of touchscreen gestures that the children could perform and the number of prompting techniques that they could follow (F=544.0407, P<0.05). No significant difference was observed in the performance of female versus male children (P>0.05). Conclusion: Children gradually learn to use mobile apps beginning at 2 years of age. They become comfortable performing single-finger gestures and following nontextual prompting techniques by 8 years of age. We recommend that these results be considered in the development of mobile apps for children.

• 대한의생명과학회지
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• 제13권4호
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• pp.369-374
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• 2007

A fingerprint is an impression of the friction ridges of all or any part of the finger. A friction ridge is a raised portion of the epidermis on the palmar (palm and fingers) or plantar (sole and toes) skin, consisting of one or more connected ridge units of friction ridge skin. There are two fundamental principles underlying the use of fingerprints as a means of identifying individuals - immutability and uniqueness. Friction ridges develop on the fetus in their definitive form before birth. Ridges are persistent throughout life except for permanent scarring. Ridge patterns and the details in small areas of friction ridges are unique and never repeated. Friction ridge patterns vary within limits, which allow for classification. We developed the high temperature-moisturizing method to obtained quality postmortem impressions from decomposing friction ridge skin. This technique is a simple procedure that uses boiling water to recondition the skin. This reconditioning process enhances detail present on the fingers and exposes ridge detail not visible to the naked eye. Therefore, we can recover the quality fingerprints, even from the worst decomposed bodies.

• 대한치과보철학회지
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• 제39권6호
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• pp.599-610
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• 2001

Due to an increasing interest in esthetics and concerns about toxic and allergic reactions to certain alloys, patients and dentists have been looking for metal-free tooth-colored restorations. Recent improvement in technology of new all-ceramic materials and composite materials has broadened the options for esthetic single crown restorations. The aim of this investigation was to study the fracture strength of the metal-free posterior single crowns fabricated using two recently introduced systems, Empress 2 ceramic and Targis-Vectris. Forty premolar-shaped stainless steel dies with the 1mm-wide circumferential shoulder were prepared. Ten cylindrical crowns having a diameter of 8.0mm and total height of 7.5mm were fabricated for each crown system respectively(PFM, Empress staining technique, Empress 2 layering technique, and Targis- Vectris). The crowns were filled with cement and placed on the stainless steel dies with firm finger pressure. The crowns were then stored in distilled water at room temperature for 24 hours before testing. The crowns were tested for fracture strength in an Instron universal testing machine (Instron 6022). With a crosshead speed of 1mm/min the center of the occlusal surface of the crown was loaded using a 4-mm-diameter stainless steel ball until fracture occurred. The fracture surfaces of the crowns were gold coated and examined using scanning electron microscopy(Jeol JSM-840 Joel Ltd., Akishima, Tokyo, Japan). Within the parameters of this study the following conclusions were drawn: 1. The mean fracture strength for PFM crowns was 5829(${\pm}906$)N; for Empress staining technique the fracture strength was 1697(${\pm}604$)N; for Empress 2 Layering technique the fracture strength was 1781N(${\pm}400$)N, and the fracture strength for Targis- Vectris was 3093(${\pm}475$)N. 2. The fracture strength of the PFM crowns was significantly higher than that of the Empress 2 and the Targis-Vectris crowns (P<0.05). 3. The fracture strength of the Targis-Vectris crowns was significantly higher than that of the Empress 2 crowns (P<0.05). 4. No statistical difference was found when Empress staining technique was compared with Empress 2 layering technique. 5. The SEM image of fracture surface of Empress 2 crown showed a very dense microstructure of the lithium disilicate crystals and the SEM image of fracture surface of Targis-Vectris crown showed indentations of Vectris and some fibers tom off from Vectris.

• 대한치과보철학회지
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• 제54권3호
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• pp.226-233
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• 2016

목적: 본 연구는 수복물의 적합도를 계측하는 두 가지 측정방법을 평가하기 위해 CAD-CAM (computer aided design-computer aided manufacturing)과 열가압 소성법으로 전부 도재관을 제작하고 micro CT와 cross-section technique으로 전부 도재관의 적합도를 비교하고자 하였다. 재료 및 방법: 하악 제 1대구치 레진 치아를 전부 도재관을 위한 지대치를 형성하고 PMMA (polymethylmethacrylate) 레진 블록을 가공하여 10개의 시편을 복제하였다. 복제한 레진 다이의 인상을 채득하고 모형을 제작하여 5개는 열가압 소성법으로 IPS e.max Press (Ivoclar Vivadent, Schaan, Liechtenstein) 도재관을 제작하였다. 다른 5개의 시편은 CAD-CAM 가공법(Ceramil motion 2, Amann Girrbach, Koblach, Austria)을 이용하여 IPS e.max CAD 도재관을 제작하였다. 각 레진 다이에 전부 도재관을 인산아연 시멘트(Fleck's zinc cement, Keystone industries, Gibbstown, NJ, USA)로 손가락 압력에 의해 합착하였다. 변연 및 내면 적합도를 측정하기 위해서 합착된 시편 10개를 먼저 micro CT로 촬영하여 협-설 시상면의 영상정보를 획득하였다. 그 후 절단 시편을 만들어 주사전자현미경으로 micro CT와 동일한 지점의 간극을 측정하였다. SPSS 22.0 프로그램을 이용하여 각 측정 지점에서 제작 방식별, 측정 방식별로 Mann-Whitney 검정 방법을 통해 유의차 검증을 시행하였다. 결과: Micro CT와 주사전자현미경으로 측정한 변연 및 내면 적합도는 유사하였으며, 통계적으로 유의한 차이를 보이지 않았다. 두 가지 제작법의 도재관은 변연 및 내면 적합도에 유의한 차이가 없었다. 결론: CAD-CAM과 열가압소성으로 제작한 전부 도재관은 적합도에 차이를 보이고 있지 않으며, Micro CT와 주사전자현미경을 이용한 측정 방식 모두 임상적으로 이용 가능할 것으로 사료된다.

• 한국컴퓨터정보학회논문지
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• 제17권6호
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• pp.173-182
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• 2012

최근 스마트 폰의 발전으로 위치 정보의 활용도가 높아지고 있다. 기존에 측위 시스템은 GPS를 이용한 위치 측위를 하였다. 하지만 실내는 GPS 신호를 사용할 수 없으며, GPS 사용할 경우 위치 부정확의 문제점이 발생된다. 실내에서의 측위 문제를 해결하기 위하여 실내를 기반으로 하는 위치 측위 기법이 연구되었다. 실내를 기반으로 하는 많은 측위 기법으로는 RFID, UWB, WLAN 등의 다양한 기법이 존재한다. 하지만 WLAN를 이용한 위치 측위기법이 실생활에 활용하기 가장 접합하다. WLAN을 이용한 실내 측위 기법은 크게 2가지로 나뉘는데 첫째는 삼각 측량 기법이고, 둘째는 핑거프린트 기법이다. 그중 핑거 프린트 기법이 정확도가 높기 때문에 많이 쓰인다. 하지만 핑거 프린트 기법을 사용하기 위해서 구축하는 시간이나 구축을 위한 자원 소모가 많은 단점이 있다. 본 논문에서는 이러한 문제점을 해결하기 위한 실내 환경에서 WLAN 기반의 가상의 핑거 프린트 구축 기법을 제안한다. 제안된 기법은 기존의 실내 환경을 셀 환경으로 구분하였으며, 각각의 셀 안의 핑거 프린트 위치 점을 가상의 그리드 맵으로 나타내었다. 그리고 가상의 위치점에 예측된 가상의 시그널 값을 넣어줌으로써 빠르게 핑거프린트 시스템을 구축한다. 또한 이렇게 구축된 시그널 값들은 실측위 값과는 다른 값을 가질수 있기 때문에 이러한 문제를 해결하기 위한 Splite-tree를 이용한 보정 기법을 제안한다. 보정 기법을 통하여 짧은 시간 동안 정확도가 향상됨을 보인다.

• Archives of Plastic Surgery
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• 제38권6호
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• pp.829-835
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• 2011

Purpose: The two major concerns in skin grafting are poor color match in the recipient site and the donor site morbidity. And, glabrous skin on the palmar aspect of the hands and plantar aspect of the feet attributes define the skin on the palm and fingers sole as functionally and aesthetically different from skin on other parts of the body. When there is a glabrous skin defect, it should be replaced with similar skin to restore function and aesthetics. The palmar crease areas were used to minimize these problems. The purpose of this study is to present the precise surgical technique of the full thickness skin graft using distal palmar and midpalmar creases for aesthetic better outcome for hand injuries. Methods: From May 2006 to April 2010, 10 patients with 11 defects underwent glabrous full thickness skin grafting of finger defects. Causes included seven machinery injuries, two secondary burn reconstructions, and one knife injury. Donor sites included ten glabrous full thickness skin graft from the distal palmar crease and one from the midpalmar crease. Results: Follow-up ranged from 3 months to 24 months. All glabrous skin grafts demonstrated complete taking the recipient sites and no incidence of the complete or partial loss. The donor site healed without complications, and there were no incidences of significant hypopigmantation, hyperpigmentation, or hypertrophic scarring. Conclusion: The important aspects of this method involve immediate return of glabrous skin to the defect site and restoration of the recipient site's crease by simple primary closure from adjacent skin. The glabrous skin of the palm provides the best tissue match for the reconstruction of the hands, but only a limited amount of tissue is available for this purpose. Full thickness skin grafting using palmar crease of the defects is the ideal way of reconstructing glabrous skin to restore both function and aesthetics and minimize donor site morbidity.

• Membrane and Water Treatment
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• 제1권3호
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• pp.215-230
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• 2010

Poly(vinylidene fluoride-co-hexafluoropropylene), PVDF-HFP, hollow fiber membranes were prepared by the dry/wet spinning technique using different polyethylene glycol (PEG) concentrations as non-solvent additive in the dope solution. Two different PEG concentrations (3 and 5 wt.%). The morphology and structural characteristics of the hollow fiber membranes were studied by means of optical microscopy, scanning electron microscopy, atomic force microscopy (AFM) and void volume fraction. The experimental permeate flux and the salt (NaCl) rejection factor were determined using direct contact membrane distillation (DCMD) process. An increase of the PEG content in the spinning solution resulted in a faster coagulation of the PVDF-HFP copolymer and a transition of the cross-section internal layer structure from a sponge-type structure to a finger-type structure. Pore size, nodule size and roughness parameters of both the internal and external hollow fiber surfaces were determined by AFM. It was observed that both the pore size and roughness of the internal surface of the hollow fibers enhanced with increasing the PEG concentration, whereas no change was observed at the outer surface. The void volume fraction increased with the increase of the PEG content in the spinning solution resulting in a higher DCMD flux and a smaller salt rejection factor.

• 방송공학회논문지
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• 제19권1호
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• pp.83-95
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• 2014

최근 손과 손가락을 인식하는 기술은 HCI(human computer interaction)에서 자연스럽고 친숙한 환경을 제공하기 위한 기술로 주목 받고 있다. 본 논문에서는 깊이 카메라를 이용하여 손과 손가락의 모양을 검출 및 인식하는 방법을 제안하고, 그 인식 결과를 활용하여 다양한 기기와 상호연동 할 수 있는 MPEG-U 기반 향상된 사용자 상호작용 인터페이스 시스템을 제안한다. 제안하는 시스템은 깊이 카메라를 이용하여 손을 검출한 후, 손목의 위치를 찾아 최소 손 영역을 검출한다. 이어서 검출된 최소 손 영역으로부터 손가락 끝점을 검출 한 후, 최소 손 영역의 중심점과 손가락 끝점간의 뼈대를 만든다. 이렇게 만든 뼈대의 길이와 인접 뼈대간의 각도차를 분석하여 손가락을 판별한다. 또한, 제안하는 시스템은 사용자가 MPEG-U에서 정의하는 다양한 심벌들을 손 자세로 취하였을 때 제안 방법을 이용하여 손 자세를 인식하고, 인식 결과를 상호연동 가능한 MPEG-U 스키마 구조로 표현한다. 실험에서는 다양한 환경에서 제안하는 손 자세 인식 방법의 성능을 보인다. 또한, 제안 시스템의 상호연동성을 보이기 위해 인식 결과를 MPEG-U part2 표준에 맞는 XML 문서로 표현하고, MPEG-U 참조 소프트웨어를 이용하여 그 표현 결과에 대한 표준 부합성을 검증한다.