• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2008년도 제39회 하계학술대회
• /
• pp.2062-2064
• /
• 2008

○○양수 발전소에서 운전되고 있는 SFC에서 양수모드 운전시 간헐적으로(1회/1-3개월) 승속실패(승속실패 시점은 대략 정격속도(300RPM)의 10%인 30RPM 전,후) 사례가 발생하나 SFC 제어 창에는 Alarm이나 Trip 관련 경보가 전혀 발생되지 않는 등 비정상 운전임에도 불구하고 원인을 파악할 수 있는 관련 정보를 취득할 수 없는 상황에서 SFC를 포함하여, 관련되어 운전되는 AVR, 인터페이스 판넬 등에 대하여 정밀점검을 시행하고, 원인을 규명함과 동시에 정상화 시킨 진단 사례임.

• 대한기계학회논문집B
• /
• 제31권2호
• /
• pp.151-158
• /
• 2007

The mechanism of power transmission from motor torque to stem thrust and the operation characteristic of each stroke position are analyzed using the diagnostic signal, and effects of differential pressure on the performance of motor operated flexible wedge gate valve are investigated. Test facility consists of 76 mm motor operated valve(flexible wedge type), pump and pipe system. Static and dynamic test are performed separately, and two differential pressure conditions are applied in the dynamic test. To evaluate the performance of valve, test signals for the torque, thrust, current, voltage and stroke length are acquired by using UDS which is diagnosis device for motor operated valve, and each diagnostic signal is analyzed and compared. The characteristic of valve performance factors such as stem factor, rate of loading, valve factor, are evaluated, and these factors are found to be severely influenced by the fluid differential pressure.

• Neurospine
• /
• 제15권4호
• /
• pp.306-322
• /
• 2018

This review introduces the current technique of photoacoustic imaging as it is applied in imaging-guided surgery (IGS), which provides the surgeon with image visualization and analysis capabilities during surgery. Numerous imaging techniques have been developed to help surgeons perform complex operations more safely and quickly. Although surgeons typically use these kinds of images to visualize targets hidden by bone and other tissues, it is nonetheless more difficult to perform surgery with static reference images (e.g., computed tomography scans and magnetic resonance images) of internal structures. Photoacoustic imaging could enable real-time visualization of regions of interest during surgery. Several researchers have shown that photoacoustic imaging has potential for the noninvasive diagnosis of various types of tissues, including bone. Previous studies of the surgical application of photoacoustic imaging have focused on cancer surgery, but photoacoustic imaging has also recently attracted interest for spinal surgery, because it could be useful for avoiding pedicle breaches and for choosing an appropriate starting point before drilling or pedicle probe insertion. This review describes the current instruments and clinical applications of photoacoustic imaging. Its primary objective is to provide a comprehensive overview of photoacoustic IGS in spinal surgery.

• Investigative Magnetic Resonance Imaging
• /
• 제23권3호
• /
• pp.179-201
• /
• 2019

Portable low-cost magnetic resonance imaging (MRI) systems have the potential to enable "point-of-care" and timely MRI diagnosis, and to make this imaging modality available to routine scans and to people in underdeveloped countries and areas. With simplicity, no maintenance, no power consumption, and low cost, permanent magnets/magnet arrays/magnet assemblies are attractive to be used as a source of static magnetic field to realize the portability and to lower the cost for an MRI scanner. However, when taking the canonical Fourier imaging approach and using linear gradient fields, homogeneous fields are required in a scanner, resulting in the facts that either a bulky magnet/magnet array is needed, or the imaging volume is too small to image an organ if the magnet/magnet array is scaled down to a portable size. Recently, with the progress on image reconstruction based on non-linear gradient field, static field patterns without spatial linearity can be used as spatial encoding magnetic fields (SEMs) to encode MRI signals for imaging. As a result, the requirements for the homogeneity of the static field can be relaxed, which allows permanent magnets/magnet arrays with reduced sizes, reduced weight to image a bigger volume covering organs such as a head. It offers opportunities of constructing a truly portable low-cost MRI scanner. For this exciting potential application, permanent magnets/magnet arrays have attracted increased attention recently. A magnet/magnet array is strongly associated with the imaging volume of an MRI scanner, image reconstruction methods, and RF excitation and RF coils, etc. through field patterns and field homogeneity. This paper offers a review of permanent magnets and magnet arrays of different kinds, especially those that can be used for spatial encoding towards the development of a portable and low-cost MRI system. It is aimed to familiarize the readers with relevant knowledge, literature, and the latest updates of the development on permanent magnets and magnet arrays for MRI. Perspectives on and challenges of using a permanent magnet/magnet array to supply a patterned static magnetic field, which does not have spatial linearity nor high field homogeneity, for image reconstruction in a portable setup are discussed.

• Clinics in Shoulder and Elbow
• /
• 제14권2호
• /
• pp.236-241
• /
• 2011

목적: 이학적 검사나 단순 방사선, 정적 초음파, 자기공명영상 등의 검사를 통해 진단하기 어려운 상완 이두건 장두 아탈구의 진단 시 동적 초음파의 유용성에 대해 보고하고자 한다. 대상 및 방법: 동적 초음파를 이용해 상완 이두건 장두 아탈구로 진단된 2명의 남자환자에 대해 관절경을 이용한 연부조직 상완 이두건 장두 고정술을 시행하고 증상 및 기능적 회복 정도를 평가 하였다. 결과: 동적 초음파를 이용해 상완 이두건 아탈구를 쉽게 진단할 수 있었으며 수술 후 증상 및 기능적 평가에서도 향상을 나타내었다. 수술 후 특이한 합병증은 발생하지 않았다. 결론: 진단이 어려운 상완 이두건 장두 아탈구의 진단 시 동적 초음파의 이용은 유용한 방법으로 판단된다.

• 대한한의진단학회지
• /
• 제15권3호
• /
• pp.235-244
• /
• 2011

Objectives: There are four types of diagnostic methods in Oriental medicine, and visual inspection is the first method among them. This study was written in order to complement further understanding on visual inspection. Methods: The authors reviewed a word related with visual inspection in Nei-Ching. The authors researched static words such as bigger/smaller, longer/shorter, slower/faster, curved/straight, one-sided/fair, and groove/uplift, and active words such as extension and contraction, shake, tremor, slow, fast, walk, run, standing, lying, and sitting related with visual inspection in Nei-Ching. Results: The static words linked with visual inspection are related with skin, muscles, fat, and especially the liver, stomach, and large intestine. The active words linked with visual inspection are related with movement of muscles, fat, and bone. Conclusion: In this study, the authors provided further understanding on visual inspection in Nei-Ching. However, there was no clear reference point about appearances and movements.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제27권6호
• /
• pp.570-574
• /
• 2005

Keratoacanthoma is a benign, self-limited epithelial lesion that closely resembles Squamous cell carcinoma(SCC). Keratoacanthoma occur primarily exposed skin in male patients over 45 years of ages. although etiology is unknown, sunlight, genetic, and human papillomavirus factor have been considered. in clinical feature, rapid enlargement occurs over 4$\sim$8 weeks, resulting ultimately in a hemispheric, firm, elevated, asymptomatic nodule that contains a central plug of keratin. When fully developed, the keratoacanthoma contains a core of keratin surrounded by a concentric collar of raised skin. Over the next 4$\sim$8 weeks, static lesion persists. Then undergoes spontaneous regression over the next 6$\sim$8weeks period by expulsion of the keratin core with resorption of the mass. In histologic feature, Keratoacanthoma consists of hyperplastic squamous epithelium growing into the underlying connective tissue. The surface is covered by a thickened layer of parakeratin with central plugging. Epithelium cell shows dysplastic features and the margins the normal adjacent epithelium is elevated. The differential diagnosis includes SCC. Keratoacanthoma present as a exophytic lesion with horny keratin occupying a depression on the top of the lesion, persists static period and undergoes rapid growth compared with SCC. Keratoacanthoma is usually treated by surgical excision or curettage of the base, spontaneous regression does not occur in every case. A 60 years old male who present facial lesion visit our hospital and surgical excision was done. Biopsy result was keratoacanthoma. We report case with review of literatures.

• 대한한방부인과학회지
• /
• 제27권3호
• /
• pp.41-65
• /
• 2014

Objectives: The purpose of this study is to find out the health condition and the etiology in oriental medicine of the high school girls menstrual disorders by Sasang constitution. Methods: The data from the 795 participants were collected using a structured menstrual history questionnaire. Based on the survey responses, we had 97 adolescents with menstrual disorder as the test group and 97 adolescents without menstrual disorder as the control group. The clinical trials subjects were asked to respond to another questionnaire for identifying their constitutional types and respond to the DSOM and undergo Inbody. We identified significant variables for dysmenorrhea from comparison between the test and control group. Results: The DSOM test showed that the scores of qi stagnation, static blood, cold, dampness, phlegm, heart, kidney were significantly higher in dysmenorrhea, scant menstruation, menstruation at irregular intervals. For the Sasang constitution, there is a difference on the cause of the outbreak. Soyangin from yin deficiency, dryness and blood deficiency is associated with menstrual disorders. Taeumin from cold, dampness and qi deficiency is associated with menstrual disorders. Soeumin from heart, qi stagnation, static blood and spleen is associated with menstrual disorders. Conclusions: For the Sasang constitution, there is a difference on the cause of the outbreak. The result of a comparison of the test and control groups showed that there's no relevance to the body fat mass and body fat percentage with menstrual irregularities.

• Imaging Science in Dentistry
• /
• 제51권2호
• /
• pp.129-136
• /
• 2021

Purpose: This study investigated the effects of 1 year of training on imaging diagnosis, using static ultrasonography (US) salivary gland images of Sjögren syndrome patients. Materials and Methods: This study involved 3 inexperienced radiologists with different levels of experience, who received training 1 or 2 days a week under the supervision of experienced radiologists. The training program included collecting patient histories and performing physical and imaging examinations for various maxillofacial diseases. The 3 radiologists (observers A, B, and C) evaluated 400 static US images of salivary glands twice at a 1-year interval. To compare their performance, 2 experienced radiologists evaluated the same images. Diagnostic performance was compared between the 2 evaluations using the area under the receiver operating characteristic curve (AUC). Results: Observer A, who was participating in the training program for the second year, exhibited no significant difference in AUC between the first and second evaluations, with results consistently comparable to those of experienced radiologists. After 1 year of training, observer B showed significantly higher AUCs than before training. The diagnostic performance of observer B reached the level of experienced radiologists for parotid gland assessment, but differed for submandibular gland assessment. For observer C, who did not complete the training, there was no significant difference in the AUC between the first and second evaluations, both of which showed significant differences from those of the experienced radiologists. Conclusion: These preliminary results suggest that the training program effectively helped inexperienced radiologists reach the level of experienced radiologists for US examinations.

• 대한방사선기술학회지:방사선기술과학
• /
• 제39권3호
• /
• pp.369-376
• /
• 2016

양전자방출단영상(Positron Emission Tomography, PET)은 여러 화합물과 방사성 동위원소를 결합하여 인체 내에 주입하여 인체 내의 대사율을 정량적으로 측정할 수 있는 핵의학적 검사이다. 특히, 암 조직에서 포도당 대사가 증가되는 현상을 $^{18}F$-FDG(Fluorodeoxyglucose)를 사용하여 널리 암 진단에 활용하며, 현대에서 발병 빈도가 높은 뇌질환 중 치매 및 파킨슨 진단에도 높은 유용성을 보인다는 연구가 다수 진행되었다. 이러한 현재의 정적 정보에 시간의 동적 정보를 포함하는 동적 양전자방출단층영상(dynamic PET, dPET)을 이용할 경우, 진단을 위한 추가적인 정보가 제공되므로 진단의 정확도 향상에 기여할 수 있다. 이러한 이유로 임상 연구자 및 방사선사의 큰 관심을 받고 있으나 연구를 진행하기 위해 손쉽게 사용 가능한 도구가 부족한 실정이며, 다양하고 복잡한 수학적 알고리즘(algorithm)이나 프로그래밍(programming) 기술이 부족할 경우 연구의 활성화를 방해하는 높은 진입장벽으로 존재하게 되므로, 본 연구에서는 dPET 연구의 활성화와 손쉬운 사용을 위해서 MATLAB을 이용하여 그래픽 유저(GUI) 기반으로 하여 무료 소프트웨어를 개발하였으며, 개발된 소프트웨어인 DIA-Tool(Dynamic Image analysis-Tool)은 복잡한 수학적 영상 분석 알고리즘을 누구나 손쉽게 사용할 수 있도록 설계되었다. 향후, 많은 임상 연구자들이 DIA-Tool을 이용하여 국내의 dPET 연구 발전에 큰 도움이 될 것이라 기대된다.