• The Korean Journal of Pain
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• v.8 no.1
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• pp.149-151
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• 1995

Piriformis syndrome is a syndrome of low back and leg radiating pain thought to be due to a chronic contracture of the piriformis muscle that causes irritation of the sciatic nerve. The piriformis muscle is a flat pyramidal muscle, an external rotator and abductor of the hip, originating from the front of the sacrum and inner aspect of the sacroiliac joint, then passes laterally out of the sciatic notch to attach posteriorly to the greater trochanter of the femur, the sciatic nerve passes between the two bellies of the muscle. Mechanical irritation of the sciatic nerve by an inflammatory reaction of the piriformis muscle and its fascia at this pelvic level causes pain to radiate in the dermatomal regions of the nerve roots similar to that disk entrapment. diagnosis of piriformis syndrome is made primary on the basis of history and clinical examination. The incidence is considerably higher in women, with the reported ratio of women to men of 6:1. These patients frequently present with associated symptoms of pelvic pain and/or dyspareunia. Symptoms are usually unilateral but occasionally be bilateral. We had a 42 year-old woman patient with low back and left leg radiating pain and dyspareunia treated by caudal steroid and local anesthetic.

• The Korean Journal of Pain
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• v.28 no.1
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• pp.52-56
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• 2015

Painful periarticular calcification most commonly occurs within the rotator cuff of the shoulder and rarely around the elbow, hip, foot, and neck. As acute inflammatory reaction develops, severe pain, exquisite tenderness, local swelling, and limitation of motion with pain occur. In case of calcific tendinitis of the shoulder, it can be easily diagnosed according to the symptoms and with x-ray. However, in lesions of the hip, as it is a rare location and usually involves pain in the posterolateral aspect of the thigh, which can simulate radicular pain from a lumbar intervertebral disc, it could be difficult to diagnose. Hence, physicians usually focus on lumbar lesions; therefore, misdiagnosis is common and leads to a delayed management. Here, we report the case of a 30-year-old female patient with calcific tendinitis of the rectus femoris that was successfully managed with ultrasound-guided steroid injection. This study offers knowledge about the rectus femoris calcification.

• Clinics in Shoulder and Elbow
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• v.9 no.1
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• pp.68-72
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• 2006

Purpose: To demonstrate arthroscopically the presence of bilateral shoulder "mirror lesions" due to overhead work. Materials and Methods: A cross-sectional study was performed in a historical cohort of 10 male tire plant workers who underwent MRI studies of both shoulders. Bilateral intraarticular shoulder pathology was diagnosed by magnetic resonance imaging and confirmed by arthroscopy. "Mirror lesions" were defined as similar pathology between an individual patient's two shoulders. Results: We report on ten patients who had bilateral "mirror lesions." The most common mirror lesions were tears of the rotator cuff. Most patients (7 of 10) had more than one mirror lesion in their shoulders. There were two bilateral full thickness tears involving the supraspinatus and infraspinatus, four bilateral partial thickness supraspinatus tears, six bilateral partial or upper corner lesion complete subscapularis tears, and one bilateral complete supraspinatus tear. Conclusion: Occupational overhead work with simultaneous use of both arms is associated with bilateral shoulder lesions verified by arthroscopy. By demonstrating the work-related bilateral shoulder involvement, this study suggests an etiopathogenesis for these lesions and provides rational for developing worksite prevention strategies.

• Clinics in Shoulder and Elbow
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• v.3 no.1
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• pp.33-38
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• 2000

Objectives: The purpose of this study was to grading the severity of intra-articular lesions and evaluate the effects of arthroscopic surgery after manipulation of the resistant frozen shoulder. Materials and Methods : Forty-eight cases from 44 subjects, median age of 53, who underwent arthroscopic surgery after manipulation with minimum follow-up of 12 months were chosen. The UCLA shoulder rating scale was applied, and average scale was 18.2 points. Results: Twelve cases out of our series showed as rotator cuff tear which could produce secondary frozen shoulder. In postoperative follow up, 34 subjects complained of no pain or noctalgia, 5 showed mild degree of pain, 8 with mild degree of remained limited range of motion, and only 1 with no improvement. When viewed with UCLA shoulder rating scale, the most improved aspect was pain, and satisfaction of patient was following. And final average scale was 31.9 points. Conclusion: Our study revealed that arthroscopic surgery after manipulation showed favorably high final scale and patient's satisfaction. Therefore, we recommend this modality for treatment of resistant frozen shoulder in a point of view that the diagnosis and treatment can be done simultaneously.

• Corrosion Science and Technology
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• v.12 no.4
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• pp.179-184
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• 2013

Pipe wall thinning caused by erosion and corrosion can adversely affect the operation of aged nuclear power plants. Some injured workers owing to pipe rupture has been reported and power reduction caused by unexpected pipe damage has been occurred consistently. Therefore, it is important to develop erosion-corrosion damage prediction model and investigate its mechanisms. Especially, liquid droplet impingement erosion(LDIE) is regarded as the main issue of pipe wall thinning management. To investigate LDIE mechanism with corrosion environment, we developed erosion-corrosion damage simulation apparatus and its capability has been verified through the preliminary damage experiment of 6061-Al alloy. The apparatus design has been based on ASTM standard test method, G73-10, that use high-speed rotator and enable to simulate water hammering and droplet impingement. The preliminary test results showed mass loss of 3.2% in conditions of peripheral speed of 110m/s, droplet size of 1mm-diameter, and accumulated time of 3 hours. In this study, the apparatus design revealed feasibility of LDIE damage simulation and provided possibility of accelerated erosion-corrosion damage test by controlling water chemistry.

• Korean Journal of Acupuncture
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• v.23 no.1
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• pp.95-109
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• 2006

Objectives : There has been a considerable debate about how to best control for placebo effects in clinical trials of acupuncture. Recently several sham needles were developed and validated. This study aimed at summarising the validation studies of these needles and evaluating the outcomes of the randomised controlled trials (RCTs) using them. Methods : Computerised literature searches were performed using 'acupuncture' AND 'placebo OR sham' with a limitation of the results to RCTs in Medline via PubMed and the Cochrane Library. Only formally validated sham needle controlled studies were included. Data were extracted regarding study design, condition, sample size, credibility testing, intervention and outcomes. Methodological quality was assessed using a modified Jadad scale. Results : Three validated sham needles by Streitberger, Park, and Fink, were identified. Acupuncture's effectiveness for various conditions was tested using these needles in 12 RCTs. Real acupuncture was superior to sham acupuncture for rotator cuff tendonitis and hypertension. No significant differences between real acupuncture and sham acupuncture emerged for chemotherapy-related nausea and vomiting, postoperative nausea and vomiting, menstrually related migraine, acute stroke rehabilitation, chronic/episodic tension-type headache, neutrophil respiratory burst in healthy volunteers, alcohol withdrawal symptoms and chronic poststroke leg spasticity. Conclusions : The new sham devices have been adequately validated and may be useful tools for investigating specific research question. In spite of the sham needle's limits, the results of RCTs using such devices tend to suggest that the clinical effects of acupuncture are largely due to a placebo response.

• Journal of Yeungnam Medical Science
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• v.18 no.2
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• pp.170-186
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• 2001

Musculoskeletal ultrasound (MSUS) has newly evolved by the mechanical improvement of the machine over past several years, becoming a part of imaging techniques for the evaluation of variable diseases in the musculoskeletal system. MSUS has proven diagnostic superiority in pathologies including rotator cuff disease of the shoulder, lateral epicondylitis of the elbow, diseases of the peripheral nerve, detection of intra-articular loose bodies and soft tissue foreign bodies, and in evaluating small superficial soft tissue tumors such as ganglion, epidermoid cyst, and glomus tumor. Besides, MSUS is very useful for obtaining tissue or fluid via percutaneous fine needle aspiration and/or biopsy for the histopathologic diagnosis. Combining MSUS with MR would play a great role in the field of the diagnostic imaging of the musculoskeletal system. The MSUS examiner should have the knowledge of cross-sectional anatomy, and of the mechanical and physical properties of ultrasound in order to interpret the ultrasound findings accurately and properly, and to avoid diagnostic errors due to variable artifacts subsequently. The goal of this article is to introduce the capabilities of MSUS in certain kinds of clinical situation and to familiarize the reader with MSUS. For the purpose, author intends to describe this article according not to the disease-, or organ-based, but to the clinical problem-based format.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.3
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• pp.342-348
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• 2015

This paper presents a 1.9-GHz digital ${{\Delta}{\Sigma}}$ fractional-N PLL with a finite impulse response (FIR) filter embedded for noise suppression. The proposed digital implementation of FIR provides a simple method of increasing the number of taps without complicated calculation for gain matching. This work demonstrates 32 tap FIR filtering for the first time and successfully filtered the in-band phase noise generated from delta-sigma modulator (DSM). Design considerations are also addressed to find the optimum number of taps when the resolution of time-to-digital converter (TDC) is given. The PLL, fabricated in $0.11-{\mu}m$ CMOS, achieves a well-regulated in-band phase noise of less than -100 dBc/Hz for the entire range inside the bandwidth of 3 MHz. Compared with the conventional dual-modulus division, the proposed PLL shows an overall noise suppression of about 15dB both at in-band and out-of-band region.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.220.1-220.1
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• 2012

우주물체 전자광학 감시체계(OWL: Optical Wide-field Patrol)는 광학망원경을 통해 우주물체를 검출하는 시스템이다. 검출기 시스템의 하드웨어 구성은 Chopper, Filter Wheel, De-Rotator로 구성된 Wheel station과 CCD 카메라로 구성된다. Chopper는 CCD 영상에서 위성의 궤적을 자르는 역할을 하고 Filter Wheel은 관측대상의 파장 영역대를 선택하는 기능을 한다. 영상획득용 CCD카메라는 천문관측용 Full Frame 방식의 카메라를 사용하고 있으며 모델명 PL16803의 FLI 제품을 사용한다. 검출기시스템은 시스템 부팅 후 "Health check"를 통하여 검출기시스템의 상태를 점검하고 "과거이력관리" 및 "과거미처리 영상관리"를 점검하여 부팅 이전에 비상사태 등으로 인해, 비정상적으로 종료되어 처리되지 못한 명령이나 영상자료를 처리한다. 그리고 이에 대한 보고서를 기록하여 보관한다. 검출기시스템은 관측명령서(OCF: Observation Command File)를 받게 되면 자동 관측을 수행하며, 자동 관측 전에 "OCF 동기화"를 통하여 최신의 명령을 유지한다. 자동 관측이 종료된 후에는 획득한 영상을 처리하는 과정을 진행한다. 영상자료 처리과정 중에는 위성의 궤적을 "Line-Detection"을 통해 검출하고 World Coordinate System(WCS)를 계산 한 후, 이미지 상의 특정 위성 궤적의 좌표를 RA, DEC으로 표현되는 위치정보를 획득하도록 프로그램되어 있다. 이 외에도 운용 소프트웨어에는 자동 초점기능을 수행하는 기능도 포함하고 있다. 본 연구에서는 검출기 부분에 대한 설계 및 시험의 과정을 기술하였다.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.214.1-214.1
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• 2012

한국천문연구원은 우주물체 전자광학 감시체계 기술개발 사업을 통해 자국위성의 추적감시를 위해 0.5m 광시야 감시관측소 국제 네트워크(OWL : Optical Wide-Field patroL)를 구축할 예정이다. OWL 시스템의 설계 검증을 위해 시험모델을 개발하였고, 연구소 내에 테스트베드에 설치하여 종합적인 테스트를 수행하고 있다. OWL 시험모델은 해외 설치모델과 동일하게 제작하였으며 돔을 제외한 모든 서브시스템을 국산화하였다. 유효구경 0.5m의 Richey-Cretian 형식의 광학계로 1.75도의 광시야를 구현하였고 영상보정을 위해 5개의 보정 렌즈를 사용하였다. 인공위성 추적을 위해 초당 10도 이상 기동이 가능한 alt-az 방식의 마운트를 개발하였다. 단일 노출에서 다수의 인공위성 궤적을 얻기 위해 chopper 제어 시스템을 도입하였고, chopper, 필터휠, de-rotator, CCD 카메라 등 4개의 부분품을 하나로 묶어 간결한 back-end를 구성하였다. 시스템의 안정성 향상과 유지보수의 용이성을 위해 망원경 및 관측소 제어 전용보드를 개발하였고, 전자동 무인관측을 위한 스케줄러 및 운영소프트웨어를 개발하였다. 시험모델을 이용하여 수 개월간 테스트을 수행하고, 관측결과 분석을 통하여 문제점을 수정보완한 후 OWL 시스템의 최종 설계안을 확정할 예정이다.