• 한국가스학회지
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• 제27권2호
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• pp.7-15
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• 2023

전기식 액중형 펌프 (electrical submersible pump, ESP)는 인공채유 (artificial lift) 기법 중 적용성과 운영 효율이 높아 전 세계 생산정에서 운영되고 있다. 저류층에서 ESP 운영 시 온도·압력, 가스·오일비, 유량 등의 변수는 ESP 성능에 영향을 미치는 요소로서, 특히 생산유체 내 자유 가스 (free gas)는 ESP의 수명 및 운영 효율을 감소시키는 주요 요인에 해당한다. 이에 본 연구에서는 ESP 성능에 영향을 미치는 변수를 정량적으로 분석하고자 현장 운영조건에서 ESP 성능실험과 손상모사 실험이 가능한 환형 유동 시스템 (flow loop system) 을 개발하였다. 개발 장치는 ESP와 튜빙 (tubing)을 하나의 시스템으로 연동시켜 ESP의 고장 및 원인 진단, 튜빙의 누출 특성을 파악할 수 있는 일체형 시스템에 해당한다. 본 연구에서는 ESP 성능 평가와 관련된 단상 유체 (single phase)와 2상 유체 (two phase) 실험을 통해 ESP를 안정적으로 운영하기 위한 유동 조건을 규명하였다. 도출된 결과값은 ESP 고장 예측 및 진단 프로그램 개발을 위한 기본 자료를 제공하며, ESP 운영을 위한 최적 운영 조건 및 고장 진단을 위한 실시간 모니터링에 활용할 수 있을 것으로 판단된다.

• 한국방사선학회논문지
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• 제17권6호
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• pp.911-917
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• 2023

임상 초음파 검사를 사용한 간 표면의 결절성 변화를 관찰하는 방법은 간경변 진단에 유용하게 사용되고 있다. 하지만 초음파 영상에서 필연적으로 발생되는 speckle 노이즈는 간표면과 echo 패턴 변화의 식별을 어렵게 하므로 간경변 진단에 부정적인 영향을 끼친다. 본 연구의 목적은 간경변 초음파 영상의 노이즈를 효율적으로 줄일 수 있는 변형된 중간값 위너 필터(median modified Wiener filter, MMWF)를 모델링하여 적용 가능성을 확인하는 것이다. ACR 팬텀과 실제 간경변 환자를 통해 초음파 영상을 획득하였고, 각각의 영상마다 제안하는 MMWF 알고리즘과 conventional filter 들을 적용하였다. 획득된 초음파 영상들의 정량적 화질 평가인자로는 변동 계수(coefficient of variation, COV)와 가장자리 상승 거리(edge rise distance, ERD)를 사용하였다. ACR 팬텀과 실제 간경변 환자의 초음파 영상 모두에서 MMWF 알고리즘이 conventional filter 보다 COV와 ERD 값이 모두 향상되었음을 확인하였다. 결론적으로 제안하는 MMWF 알고리즘은 노이즈 레벨을 줄일 수 있음과 동시에 공간 분해능을 향상시킬 수 있어 간경변 환자의 진단률 향상에 기여할 수 있을 것으로 기대한다.

• The Plant Pathology Journal
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• 제31권3호
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• pp.219-225
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• 2015

The primary step for efficient control of viral diseases is the development of simple, rapid, and sensitive virus detection. Reverse transcription loop-mediated isothermal amplification (RT-LAMP) has been used to detect viral RNA molecules because of its simplicity and high sensitivity for a number of viruses. RT-LAMP for the detection of Potato virus X (PVX) was developed and compared with conventional reverse transcription polymerase chain reaction (RT-PCR) to demonstrate its advantages over RT-PCR. RT-LAMP reactions were conducted with or without a set of loop primers since one out of six primers showed PVX specificity. Based on real-time monitoring, RT-LAMP detected PVX around 30 min, compared to 120 min for RT-PCR. By adding a fluorescent reagent during the reaction, the extra step of visualization by gel electrophoresis was not necessary. RT-LAMP was conducted using simple inexpensive instruments and a regular incubator to evaluate whether RNA could be amplified at a constant temperature instead of using an expensive thermal cycler. This study shows the potential of RT-LAMP for the diagnosis of viral diseases and PVX epidemiology because of its simplicity and rapidness compared to RT-PCR.

• 한국전자파학회논문지
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• 제22권12호
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• pp.1124-1131
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• 2011

본 논문에서는 MT(Microwave Tomography)를 사용한 유방암 진단용 영상 재구성 알고리즘에 관하여 연구하였다. 사용된 유방암 진단용 시스템은 16개의 송수신 안테나로 구성되어 있으며, 신호 파형은 900 MHz 정현파를 사용하였다. 2차원 역산란 문제를 풀기 위하여 포워드 계산 방법으로 2차원 시간 영역 유한 차분법과 최척화 알고리즘으로 LMA(Levenberg-Marquardt Algorithm)를 이용하였다. 실제 유방암 환자의 MRI(Magnetic Resonance Imaging)로부터 얻은 수치 팬텀을 활용하여 영상 복원을 한 결과 유방암의 위치를 정확히 탐지함을 확인하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권11호
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• pp.5433-5438
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• 2012

Background: Hepatocellular carcinoma (HCC) is a common and aggressive malignancy. Despite of the improvements in its treatment, HCC prognosis remains poor due to its recurrence after resection. This study provides complete genetic profile for Egyptian HCC. Genome-wide analyses were performed to identify the predictive signatures. Patients and Methods: Liver tissue was collected from 31 patients with diagnosis of HCC and gene expression levels in the tumours and their adjacent non-neoplastic tissues samples were studied by analyzing changes by microarray then correlate these with the clinico-pathological parameters. Genes were validated in an independent set by qPCR. The genomic profile was associated with genetic disorders and cancer focused on gene expression, cell cycle and cell death. Molecular profile analysis revealed cell cycle progression and arrest at G2/M, but progression to mitosis; unregulated DNA damage check-points, and apoptosis. Result: Nine hundred fifty eight transcripts out of the 25,000 studied cDNAs were differentially expressed; 503 were up-regulated and 455 were down-regulated. A total of 19 pathways were up-regulated through 27 genes and 13 pathways were down-regulated through 19 genes. Thirty-seven genes showed significant differences in their expression between HCC cases with high and low Alpha Feto Protein ($AFP{\geq}600$ IU/ml). The validation for the microarray was done by real time PCR assay in which PPP3CA, ATG-5, BACE genes showed down-regulation and ABCG2, RXRA, ELOVL2, CXR3 genes showed up-regulation. cDNA microarrays showed that among the major upregulated genes in HCC are sets. Conclusion: The identified genes could provide a panel of new diagnostic and prognostic aids for HCC.

• 한국멀티미디어학회논문지
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• 제9권8호
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• pp.1054-1066
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• 2006

본 연구는 의료기관 간 정보공유를 위해 간호분류체계를 기반으로 임상문서구조(Clinical Document Architecture, CDA)의 생성과 새로운 패러다임의 병원정보시스템을 제안하였다. 간호정보 CDA는 간호진단, 간호중재 및 수행과 관련된 코딩시스템을 포함하였고 표준문서의 생성을 위해 CDA생성도구를 개발하였다. 본 연구의 목표는 개인의 필요한 간호정보를 간호전문가에게 실시간으로 제공하여 적정 간호를 제공하며 건강 증진을 도와 생산적인 삶의 질을 향상하는 것이다. 본 연구가 가지는 의의는 첫째, 국제 표준인 HL7 임상문서구조를 사용하기 위한 확장과 정제과정의 연구를 했으며, 둘째, 임상문서구조를 사용할 수 있는 웹 기반의 차세대 병원정보시스템의 구조를 제안하였다. 결론적으로, 임상문서구조에 대한 본 연구로 말미암아 평생전자의무기록(Electronic Health Record)과 임상데이터저장소(Clinical Data Repository)를 포함하여 다양한 보건의료기관 간 간호정보 공유의 기반이 될 것이다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 춘계학술발표강연 및 논문개요집
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• pp.88-88
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• 2003

Optical Emission Spectroscopy(OES) is a very important technology for real-time monitoring of plasma in a reactor during dry etching process. OES technology is non-invasive to the plasma process. It can be used to collect information on excitation and recombination between electrons and ions in the plasma. It also helps easily diagnose plasma intensity and monitor end-point during plasma etch processing. We studied high density planar inductively coupled BCl$_3$ and BCl$_3$/Ar plasma with an OES as a function of processing pressure, RIE chuck power, ICP source power and gas composition. The scan range of wavelength used was from 400 nm to 1000 nm. It was found that OES peak Intensity was a strong function of ICP source power and processing pressure, while it was almost independent on RIE chuck power in BCl$_3$-based planar ICP processes. It was also worthwhile to note that increase of processing pressure reduced negatively self-induced dc bias. The case was reverse for RIE chuck power. ICP power and gas composition hardly had influence on do bias. We will report OES results of high density planar inductively coupled BCl$_3$ and BCl$_3$/Ar Plasma in detail in this presentation.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2004년도 학술대회 논문집
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• pp.371-374
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• 2004

Induction motors are a critical component of many industrial processes and are frequently integrated in commercially available equipment. Safety, reliability, efficiency, and performance are some of the major concerns of induction motor applications. Preventive maintenance of induction motors has been a topic great interest to industry because of their wide range application of industry. Since the use of mechanical sensors, such as vibration probes, strain gauges, and accelerometers is often impractical, the motor current signature analysis (MACA) techniques have gained murk popularity as diagnostic tool. Fault tolerant control (FTC) strives to make the system stable and retain acceptable performance under the system faults. All present FTC method can be classified into two groups. The first group is based on fault detection and diagnostics (FDD). The second group is independent of FDD and includes methods such as integrity control, reliable stabilization and simultaneous stabilization. This paper presents the fundamental FDD-based FTC methods, which are capable of on-line detection and diagnose of the induction motors. Therefore, our group has developed the embedded distributed fault tolerant and fault diagnosis system for industrial motor. This paper presents its architecture. These mechanisms are based on two 32-bit DSPs and each TMS320F2407 DSP module is checking stator current, voltage, temperatures, vibration and speed of the motor. The DSPs share information from each sensor or DSP through DPRAM with hardware implemented semaphore. And it communicates the motor status through field bus (CAN, RS485). From the designed system, we get primitive sensors data for the case of normal condition and two abnormal conditions of 3 phase induction motor control system is implemented. This paper is the first step to drive multi-motors with serial communication which can satisfy the real time operation using CAN protocol.

• 한국정보통신학회논문지
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• 제10권8호
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• pp.1519-1525
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• 2006

의료서비스 분야에서 의료와 컴퓨터 기술을 결합하여 온라인상에서 언제, 어디서나, 휴대 가능한 헬스케어(Healthcare) 장비와 유 무선 인터넷을 통해 실시간으로 환자의 생체정보 데이터를 수집하고, 이를 이용하여 진단 및 응급상황 인지가 가능한 U-헬스케어(Ubiquitous Healthcare) 시스템이 생겨났다. U-헬스케어 시스템은 기존의 의료 환경에서와는 달리, 사용자(환자, 보호자, 의료인등)들은 다양한 의료서비스를 요구하게 되고, 당연히 헬스케어 장비들은 통합된 의료서비스를 제공할 수 있도록 연동되어져야 한다. 본 논문에서 홈 네트워크(Home Network) 환경에서 사용자들의 다양한 요구를 처리하기 위해 분산 객체를 이용한 U-홈 헬스케어 미들웨어를 설계하였고, 다양한 헬스케어 장비들로부터 발생되는 생체 데이터를 통합하기 위한 데이터 변환 객체를 구현하였다.

• Childhood Kidney Diseases
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• 제10권2호
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• pp.174-181
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• 2006

Purpose : To analyse the results of the renal biopsies and the clinical diagnoses of patients who had undergone percutaneous kidney biopsies in the department of pediatrics at Kyunghee University Hospital for 22 years from 1984 to 2005. Methods : We retrospectively reviewed the medical records of 1559 patients and analyzed the chief complaints that led to a renal biopsy, age, sex, histopathologic findings and diagnosis. Routine kidney biopsies were performed by automated gun biopsy guided by real time ultrasonography. The diagnoses were made based on the specimen's light microscopy, immunofluorescence microscopy and electron microscopy findings and clinical symptoms and signs. Results : The mean age of the patients was 10 years with the male to female ratio being 1.3:1. The chief complaints that led to a renal biopsy included hematuria only(753 cases, 48.3%), proteinuria only(125 cases, 8.0%) and hematuria combined with proteinuria(537 cases, 34.4%). The most frequent histopathological finding was primary glomerular disease(75.4%) which included IgA nephropathy(30.1%) and mesangial proliferative glomerulonephritis(27.6 %). Systemic disease comprised 11.4% which included Henoch-$Sch\ddot{o}nlein$ nephritis(10.5%) and lupus nephritis(0.8%). Alport syndrome was found in 1.1% of cases which was attributed to hereditary causes. 628 children(40.3%) visited the clinic due to abnormal school urine screening abnormalities and among these, 237 children had mesangial proliferative glomerulonephritis and 234 children who had IgA nephropathy were managed thereafter. Conclusion : IgA nephropathy and mesangial proliferative glomerulonephritis were the two major forms of primary glomerulonephritis found in Korean children who had kidney biopsies from 1984 to 2005.