• Archives of Plastic Surgery
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• 제50권1호
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• pp.96-100
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• 2023

The microsurgical anastomosis is integral to the success of autologous-free tissue transfer. Successful performance of this procedure relies strongly on operator dexterity, which can be made more challenging when blood and edematous fluids obscure the field of view. Workflow is impeded by intermittent irrigation and suctioning, necessitating presence of an assistant, with risk of arterial thrombosis, from vessels being drawn into suction drains. To negate these current disadvantages and minimize the barrier of entry to microvascular operations, we designed, manufactured, and patented a novel three-dimensional printed microsurgical background device with microfluidic capabilities that allow continuous suction and irrigation as well as provide platforms that enable multiangle retraction to facilitate operator autonomy. This was validated in an ex vivo model, with the device found to be superior to the current standard. We believe that this will have major applicability to the improvement of microsurgeon

• 한국의학물리학회지:의학물리
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• 제32권4호
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• pp.99-106
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• 2021

Purpose: In this study, we aimed to manufacture a patient-specific gel phantom combining three-dimensional (3D) printing and polymer gel and evaluate the radiation dose and dose profile using gel dosimetry. Methods: The patient-specific head phantom was manufactured based on the patient's computed tomography (CT) scan data to create an anatomically replicated phantom; this was then produced using a ColorJet 3D printer. A 3D polymer gel dosimeter called RTgel-100 is contained inside the 3D printing head phantom, and irradiation was performed using a 6 MV LINAC (Varian Clinac) X-ray beam, a linear accelerator for treatment. The irradiated phantom was scanned using magnetic resonance imaging (Siemens) with a magnetic field of 3 Tesla (3T) of the Korea Institute of Nuclear Medicine, and then compared the irradiated head phantom with the dose calculated by the patient's treatment planning system (TPS). Results: The comparison between the Hounsfield unit (HU) values of the CT image of the patient and those of the phantom revealed that they were almost similar. The electron density value of the patient's bone and brain was 996±167 HU and 58±15 HU, respectively, and that of the head phantom bone and brain material was 986±25 HU and 45±17 HU, respectively. The comparison of the data of TPS and 3D gel revealed that the difference in gamma index was 2%/2 mm and the passing rate was within 95%. Conclusions: 3D printing allows us to manufacture variable density phantoms for patient-specific dosimetric quality assurance (DQA), develop a customized body phantom of the patient in the future, and perform a patient-specific dosimetry with film, ion chamber, gel, and so on.

• 한국정보통신학회논문지
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• 제20권1호
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• pp.15-21
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• 2016

본 논문에서는 UHF 대역 휴대형 RFID 리더용 소형 준-야기 안테나 설계 방법에 대해 연구하였다. 안테나는 유전체 기판에 인쇄된 다이폴 투사기와 반사기로 이루어지며 마이크로스트립 선로로 급전된다. 안테나를 소형화하기 위해 다이폴과 반사기를 구부리고, 급전 마이크로스트립 선로와 코플래너스트립 선로 간 발룬은 코플래너스트립 선로에 내장형으로 구성하였다. 제안된 안테나 구조의 파라미터들이 안테나 특성에 미치는 영향을 분석하고 UHF RFID 용 주파수 대역(902-928 MHz)에 적합하도록 파라미터 값들을 조정하였다. 제작된 안테나의 크기는 $70mm{\times}75mm$이고, 특성을 실험한 결과 VSWR < 2인 대역은 892-942 MHz, UHF RFID 대역 내 이득 > 3.5 dBi, 전후방비 > 6.6 dB 이었다.

• 한국항행학회논문지
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• 제20권5호
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• pp.490-495
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• 2016

본 논문에서는 무선랜 2.4 GHz 대역 (2.4 ~ 2.484 GHz), 및 5 GHz 대역의 (5.15 ~ 5.825 GHz) 이중 대역용 마이크로 스트립 급전 인쇄형 모노폴 안테나를 제안하였다. 간결한 구조 및 우수한 무지향성 방사패턴을 얻기 위하여 2.4 GHz 모노폴 안테나에 5 GHz 대역 임피던스 정합을 위해 접지면과 이격되는 수정된 역 L-형 슬롯이 에칭된다. 제안된 안테나는 크기가 $30{\times}45mm^2$, 두께는 1.6 mm, 유전상수가 4.3인 FR4 기판에 설계 및 제작 되었다. 제안된 안테나의 제작 및 측정 결과, 임피던스 대역폭(${\mid}S_{11}{\mid}{\leq}-10dB$)이 2.4 GHz 대역에서는 270 MHz (2.22 ~ 2.48 GHz), 5 GHz 대역에서는 890 MHz (5.08 ~ 5.97 GHz)인 대역폭을 얻을 수 있었다. 특히 두 대역에서 안정되고 우수한 무지향성 방사패턴을 얻을 수 있었으며, 또한 약 4dBi 이상의 높은 이득을 얻을 수 있었다.

• 한국전자파학회논문지
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• 제17권11호
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• pp.1089-1095
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• 2006

본 논문에서는 적층 PCB에 전송 영점을 갖는 3차원의 대역 통과 필터의 회로 해석을 하였다. 대역 통과 필터의 등가 회로는 고주파 네트웍 해석에 의해 계산되어졌다. 기존의 논문들은 분포 정수 소자의 영향을 제외한 회로 모델을 구성하였지만, 제안된 모델은 이에 대한 영향을 포함한다. 그 결과 인덕터들의 내부 전기적 성분으로부터 상호 커패시턴스를 추출함으로써 하나의 전송 영점을 갖는 적층 PCB 대역 통과 필터를 설계하였다. 구조의 크기는 단지 $10mm{\times}20mm{\times}1.2mm$이다. 대역 통과 필터의 측정된 데이터는 중심 주파수인 1.84 GHz에서 1.9 dB의 삽입 손실과, 28 dB의 반사 손실을 가지며, 차단 주파수인 2.78 GHz에서 43 dB의 감쇠 특성을 보인다.

• 대한방사선기술학회지:방사선기술과학
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• 제45권3호
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• pp.205-211
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• 2022

This study aimed to provide basic data for 3D printing in the medical health field by developing upper wear fixation device (UWFD), an auxiliary device for shortening chest AP examination time on emergency room beds and non-contact with patients. The standard of hooks was modeled according to the bed frame using the Autodesk Fusion 360. It was printed with Form2 (Formlabs, Somerville, MA, USA), as SLA (stereo lithography apparatus) method, and was washed and hardened using Form Wash and Form Cure. The completed UWFD conducted an online survey on 4 items of stability, convenience, availability, preference and general characteristics. The total stability average was 3.93±0.80, the total convenience average was 3.93±0.68, the total availability average was 4.01±0.89, and the total preference average was 3.80±1.08. This study was significant in suggesting improvements in the general X-ray examination process in the emergency room by designing and making aids to easily fixing the patient's top to the frame of the emergency bed while meeting promptness and non-contact with the patient.

• 한국전기전자재료학회논문지
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• 제21권9호
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• pp.835-843
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• 2008

We have fabricated the source-drain electrodes for OTFTs by screen printing method and manufactured Ag pastes as conductive paste. To obtain excellent conductivity and screen-printability of Ag pastes, the dispersion characteristics of Ag pastes prepared from two types of acryl resins with different molecular structures and Ag powder treated with caprylic acid, triethanol amine and dodecane thiol as surfactant respectively were investigated. The Ag pastes containing Ag powder treated with dodecane thiol having thiol as anchor group or AA4123 with carboxyl group(COOH) of hydrophilic group as binder resin exhibited excellent dispersity. But, Ag pastes(CA-41, TA-41, DT-41) prepared from AA4123 fabricated the insulating layer since the strong interaction between surface of Ag powder and carboxyl group(COOH) of AA4123 interfered with the formation of conduction path among Ag powders. The viscosity behavior of Ag pastes exhibited shear-thinning flow in the high shear rate range and the pastes with bad dispersion characteristic demonstrated higher shear-thinning index than those with good dispersity due to the weak flocculated network structure. The output curve of OTFT device with a channel length of 107 ${\mu}m$ using screen-printed S-D electrodes from DT-30 showed good saturation behavior and no significant contact resistance. And this device exhibited a saturation mobility of $4.0{\times}10^{-3}$ $cm^2/Vs$, on/off current ratio of about $10^5$ and a threshold voltage of about 0.7 V.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2016년도 추계학술발표대회
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• pp.518-519
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• 2016

AOI 검사기는 SMT 공정 상에서 PCB (printed Circuit Board) 상의 부품들을 카메라로 촬영하고 촬영된 영상을 2D 혹은 3D 형태의 이미지로 재구성하고 분석하여 이상 여무를 판단하는 장비다. 검사를 하고자 하는 PCB의 크기가 카메라가 촬영할 수 있는 영역 보다 큰 경우가 대부분이기 때문에 PCB 상에 마운트 되어 있는 부품들을 모두 촬영하기 위해서는 여러 차례 나누어 촬영해야 할 필요가 있으며 이 때문에 PCB 상에 촬영해야 하는 부품들을 가능한 FOV에 많이 포함될 수 있도록 여러 FOV 영역으로 나누고 이렇게 나누어진 FOV 영역들을 최적의 경로로 이동하며 촬영할 수 있도록 하기 위한 알고리즘이 필요하다. 기존 논문들은 대부분 이 문제를 해결하기 위한 알고리즘에 대해 다루어 왔다. 일반적으로 생산이 진행되는 시점에서는 검사해야 할 PCB에 대한 정보 (PCB의 크기, 부품의 위치, 크기, 종류 등)는 이미 정해져 있기 때문에 경로 계획 최적화 수행은 PCB 정보에 변동이 없다면 한차례만 하면 된다. 하지만 검사를 할 수 있도록 Teaching 하는 단계에서는 PCB 정보가 지속적으로 변경될 수 있으며 이에 따라 최적화를 여러 차례 수행해야 할 필요성이 있다. 최적화를 위한 처리 시간은 부품의 개수, PCB 상에서의 분포정도등에 따라 증가하기 때문에 PCB 정보가 변경될 때 마다 최적화를 수행하게 되면 비효율적으로 처리 시간이 증가하게 된다. 본 논문에서는 이 문제에 대해 연구하고 해결책을 제시하였다.

• 한국염색가공학회지
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• 제26권1호
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• pp.13-21
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• 2014

The object of this research is to perform the basic research for the development of selectively permeable membrane fabrics which is suitable for korean military in sense of embattlement. As a key factor of selectively permeable membrane fabrics which is suitable for korean military, this study selected the best PVA thickness and membrane selection for DMMP protection, pre-treatment method for conformational stability of face fabric and water/oil repellent process condition. Especially as the PVA coating thickness of the fabrics increase, peneration of DMMP decrease including water vapor permeation is lower. This study shows how physical features and permeability of chemical agents can be influenced by pre-treatment methods, the selection of selectively permeable membrane, the thickness of PVA etc. Results showed that outer shell / PVA / e-PTFE materials possessed performance with superior water vapor permeation (Over $3,000g/m^2/day$) and protective capability against DMMP vapor ($0.6{\mu}g/cm^2{\cdot}16hr$).

• 한국BIM학회 논문집
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• 제9권3호
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• pp.8-18
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• 2019

Precast concrete manufacturing has proved economies of scale through the repetitive production by means of standardization, automation, and prefabrication. Advanced digital design and fabrication technologies can empower its benefits by enabling mass customization in the building design and construction. This study analyzed five case studies in terms of 1) design intent and background, 2) module development and facade construction, 3) integrated process among project stakeholder. This article has attempted to establish the following three points in conclusion: 1) Form generating digital design tools such as Rhino, CATIA, Generative Component, and Digital Project were implemented to produce parametric surface pattern and rationalization to maximize existing precast manufacturing benefits. Also, BIM program has been used to promote coordination and communication among engineering consultants and contractors, 2) In addition to traditional precast concrete materials, GFRC, RFP, brick cladding precast and 3D printed mould have been introduced to reduce the weight and cost and to comply the code from the zoning, seismic, and fireproof requirements, 3) Design-assist contract, design-assist financial support, and co-location measures have been introduced to facilitate collaboration between architect, fabricator, and contractor from the beginning of the project.