• 한국가스학회지
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• 제13권3호
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• pp.1-6
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• 2009

최근 화학 산업이 발전함에 따라 고압설비가 널리 이용되고 있다. 이러한 고압 설비는 편리성과 함께 많은 위험을 내포하고 있다. 파열판 안전장치는 고압설비의 안전사고로부터 설비와 생명을 보호하는 장치이다. 파열판 안전장치는 홀더, 파열판, 버큠서포트로 구성되어져 있으며, 다양한 환경 조건에서 부식되거나 파괴되는 단점이 있다. 본 논문에서는 부식 저항성이 우수하여 파열판 안전장치의 소재로 많이 사용되고 있는 STS 316L stainless steel 소재를 이용해서 제작한 파열판 안전장치를 CATIA V5를 이용하여 3차원 모델링을 수행하고, 유한요소해석을 통하여 소재의 두께와 높이에 따라 파열판 안전장치의 파열에 영향을 미치는 요인을 분석하였다.

• Journal of Korean Neurosurgical Society
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• 제40권5호
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• pp.346-350
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• 2006

Objective : The ability to induce segmental lordosis has been reported to be marginal with transforaminal lumbar interbody fusion[TLIF]. Therefore, we analyzed the short-term radiological outcomes of TLIF using $8^{\circ}$ wedged cages for isthmic spondylolisthesis. Methods : Twenty-seven patients with isthmic spondylolisthesis who underwent single level TLIF with pedicle screw fixation[PSF] using $8^{\circ}$ wedged cages were retrospectively evaluated. Changes in disc height, degree of anterolisthesis, segmental lumbar lordosis, whole lumbar lordosis and L1 axis S1 distance were evaluated using standing lateral radiographs before surgery, at 6 weeks follow-up and at the final follow-up. Results : The mean age of the patients was 49.9 years [range, 38 to 64 years]. The affected levels were L4-5 in 17 cases and L5-S1 in 10. There were 18 cases of Grade I isthmic spondylolisthesis and 9 cases of Grade II. At a mean follow-up duration of 9.9 months [range, 6 to 18 months], the disc height [p< 0.001] was significantly increased, and the degree of anterolisthesis was significantly reduced [p< 0.001]. Regarding the sagittal balance, the segmental lumbar lordosis was significantly increased [p=0.01], but other parameters were not significantly changed after surgery. Conclusion : TLIF with PSF using $8^{\circ}$ wedged cages significantly increased the segmental lumbar lordosis.

• Journal of Korean Neurosurgical Society
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• 제53권1호
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• pp.6-12
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• 2013

Objective : This consecutive retrospective study was designed to analyze and to compare the efficacy and outcomes of anterior cervical discectomy and fusion (ACDF) using a fibular and femur allograft with anterior cervical plating. Methods : A total of 88 consecutive patients suffering from cervical degenerative disc disease (DDD) who were treated with ACDF from September 2007 to August 2010 were enrolled in this study. Thirty-seven patients (58 segments) underwent anterior interbody fusion with a femur allograft, and 51 patients (64 segments) were treated with a fibular allograft. The mean follow-up period was 16.0 (range, 12-25) months in the femur group and 19.5 (range, 14-39) months in the fibular group. Cage fracture and breakage, subsidence rate, fusion rate, segmental angle and height and disc height were assessed by using radiography. Clinical outcomes were assessed using a visual analog scale and neck disability index. Results : At 12 months postoperatively, cage fracture and breakage had occurred in 3.4% (2/58) and 7.4% (4/58) of the patients in the femur group, respectively, and 21.9% (14/64) and 31.3% (20/64) of the patients in the fibular group, respectively (p<0.05). Subsidence was noted in 43.1% (25/58) of the femur group and in 50.5% (32/64) of the fibular group. No difference in improvements in the clinical outcome between the two groups was observed. Conclusion : The femur allograft showed good results in subsidence and radiologic parameters, and sustained the original cage shape more effectively than the fibular allograft. The present study suggests that the femur allograft may be a good choice as a fusion substitute for the treatment of cervical DDD.

• 대한영상의학회지
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• 제82권4호
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• pp.862-875
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• 2021

목적 요추신경근병증이 있는 60세 이상의 환자의 신경공 협착에 영향을 줄 수 있는 인자를 자기공명영상 평가를 통해 알아보고자 하였다. 대상과 방법 요추신경근병증이 있는 60세 이상의 환자 133명이 본원에서 시행 받은 2018년 1월부터 4월까지의 요추 자기공명영상을 대상으로 하였다. 제4/5 요추간과 제5 요추/제1 천추간에서 신경공 협착이 있는 군과 없는 군으로 나눈 후 척추전방전위증, 척추후방전위증, 추간판 간격 감소, 추간판탈출증, 중심성 척추관 협착, 황색인대비후, 척추후관절 비후 여부를 2명의 판독자가 분석한 후 단변량 및 다변량 로지스틱 회귀분석을 시행하였다. 결과 단변량 분석에서 제4/5 요추간에 대해 추간판 간격 감소(p = 0.006), 제5 요추/제1 천추간에 대해서는 척추전방전위증(p = 0.005)과 척추후관절 비후(p = 0.006)가 신경공 협착과 유의한 연관성을 보였다. 다변량 분석에서는 제4/5 요추간에 대해 추간판 간격 감소[odds ratio(이하 OR) = 4.272; 95% confidence interval (이하 CI) 1.736~10.514]가 신경공 협착과 관련된 인자였다. 제5 요추/제1 천추간에서는 척추전방전위증(OR = 3.696; 95% CI 1.297~10.530)과 척추후관절 비후(OR = 6.468; 95% CI 1.238~32.617)가 이와 관련된 인자였다. 결론 제4/5 요추간에서는 추간판 간격 감소가, 제5 요추/제1 천추간에서는 척추전방전위증과 척추후관절 비후가 신경공 협착과 관련된 인자였다.

• 대한전자공학회논문지TC
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• 제41권8호
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• pp.125-130
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• 2004

지금까지의 UWB 안테나는 무지향성이면서 동시에 광대역을 만족하지 못했다. 하지만 UWB 통신채널 환경에서는 이러한 특성이 필수적이다. 본 논문에서는 UWB용 광대역 타원형 모노폴 안테나를 제안하였다. 광대역 특성을 갖는 평판형 모노폴 안테나는 최근 많이 연구되고 있으며 제안한 안테나는 10dB 기준으로 3.5GHz -12GHz의 주파수 밴드위스를 갖는다. 방사패턴은 3.5GHz - 10GHz까지 무지향성 특성을 보였다. 제안한 안테나는 마이크로 스트립 급전 구조와 타원형 모노폴 디스크로 구성되어 있으며 모노폴 디스크와 그라운드 사이의 높이는 정합을 결정 짖는 매우 중요한 변수이다. 제안한 안테나는 UWB 시스템에 적용이 가능할 것이다.

• Journal of information and communication convergence engineering
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• 제6권3호
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• pp.249-254
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• 2008

Moored ocean buoys are technically feasible approach for making sustained time series observation in the oceans and will be an important component of any long-term ocean observing system. The 3M disc buoy carried Zeno 3200, MCCB, Orbcomm, Global Star and Bluetooth module. The deployments have relied on Orbcomm and Global Star as the primary satellite communications system. In addition to detailing our practical experience in the use of Orbcomm and Global Star as high latitudes, we will present some of scientific sensor results regarding real-time oceanographic and meteorological parameters such as wind speed, wave height and etc. In this paper we present the design and implementation of a small-scale buoy sensor network. One of the major challenges is that the network is hard to access after its deployment and hence both hardware and software must be robust and reliable.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.378.1-378
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• 2002

DVD, HD(High Density)-DVD등의 고밀도 광 디스크의 광 기록재생장치는 고 개구율(Numerical Aperature)의 대물렌즈로 집광 빔의 크기를 소형화하여 기록용량을 증대시키고 있다. 이 경우 광축과 광 디스크의 기록면에 대한 경사는 광학적인 수차가 발생되어 신호 레벨의 저하나 기록시의 피트(pit) 형성의 오류, Crosstalk등의 문제가 발생한다. 이를 극복하기 위해 직접 디스크의 경사에 따라 제어할 수 있는 픽업 구동기가 제안되어 왔지만 주로 Half Height(12.7mm)에 사용되는 틸트 구동기였으며 Slim(6.3mm)형 틸트 구동기는 제안되지 못하였다. (중략)

• 대한추나의학회지
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• 제3권1호
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• pp.43-53
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• 2002

Objectives : The object is to study a clinical effect regarding the conservative treatment of the patient who was diagnosed as the herniated Intervertebral lumbar disc(HIVD) and hospitalized in the oriental medical hospital and clinical study about the type of the HIVD. Methods. The clinical studies were done on 65 cases (hospitalized in Dept. of Oriental Rehabilitation Medicine, jaseng on oriental medical hospital from June 2001 to May 2002) who complained of low back pain or sciatica and diagnosed as HIVD on CT(computerized tomography) or MRI(magnetic resonance imaging). They were given both oriental conservative treatment and exercise during the hospitalization period. We investigated and observed 20 items about sex, age, weight, height, occupation, smoking. obesity, duration of disease, clinical symptom and treatment duration in basis of medical recording which was drawn up at patient hospitalization. We classified HIVD with 4 types(Bulging. Protruded. Extruded, Sequestered) and decided the case which simultaneously had 2 overs with Mixed type. The treatment evaluation standard was classified with 4 branches; Excellent. Good, Fair and Poor. Results & Conclusions : The treatment result of over 'fair' is bulging type 85%, protruded type 92.7%, extruded type 100% and the mixed type was 85.1 %. The effect was good in order of bulging, mixed, protruded and extruded type. It appeared most plentifully with 30 people in L4-5 and L5-S 1 disc herniation type.

• 대한물리치료과학회지
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• 제13권1호
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• pp.29-38
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• 2006

The purpose of this study lies in finding out the effect that variation of pain and body deflection posture has an influence on the static spinal stabilization after having performed spinal stabilization exercise making degenerative disc disease patients an object over 8 weeks using $CENTAUR^{(R)}$, 3-D spinal stabilization training implement. Subjects : 61 of DDD patients were made as an object of this study (mean age: 45.46 years, SD: ${\pm}12.78$, range: 16-68), their average height was 161.87cm, average weight 60.70kg, 12 males and 49 females were involved. Methods: 8 various investigations were performed and varied values were compared with reinvestigation done after having exercised 8 weeks using 3-D $CENTAUR^{(R)}$. We used VAS(Visual Analog Scale) in order to see the variation of pain intensity, MOS(Modified Oswestry Scale) in order to see activities of daily life. Results VAS was lessened from 7.50 to 2.71, limitation of routine life(MOS) from 20.26 to 9.32, there were remarkable differences statistically(p<0.05). As a result of muscular investigation for static spinal stabilization by 8 variations of body deflection, muscular strength were all increased and there were remarkable differences statistically(p<0.05). Conclusions : It has been turned out that pain and limitation of daily life was lessened as a result of making 61 of degenerative disc disease patients exercised 8 weeks using $CENTAUR^{(R)}$, 3-D spinal stabilization training implement, deep muscular power was increased. Thus it has been turned out that 3-D lumbar stabilization exercise has an effect on the spinal muscles strengthening and alleviation of their pain for degenerative disc disease.

• Journal of Korean Neurosurgical Society
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• 제51권3호
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• pp.135-140
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• 2012

Objective : To evaluate radiographic results of anterior fusion methods in two-level cervical disc disease : tricortical autograft and plate fixation (ACDF-AP), cage and plate fixation (ACDF-CP), stand-alone cage (ACDF-CA), and corpectomy and plate fixation (ACCF). Methods: The numbers of patients were 70 with a minimum 6 month follow-up (ACDF-AP : 12, ACDF-CP : 27, ACDF-CA : 15, and ACCF : 16). Dynamic simple X-ray and computed tomography were evaluated preoperatively, postoperatively, 6 month, and at the final follow-up. The fusion and subsidence rates at the final were determined, and global cervical lordosis (GCL), cervical range of motion, fused segment angle (FSA), and fused segment height (FSH) were analyzed. Results: Nonunion was observed in 4 (25%) patients with ACDF-CA, 1 (8%) patient with ACDF-AP, 1 (4%) patient with ACDF-CP. The number of loss of FSH (%) more than 3 mm were 2 patients (16%) in ACDF-AP, 3 patients (11%) in ACDF-CP, 5 patients (33%) in ACDF-CA, and 3 patients (20%) in ACCF. The GCL was decreased with ACDF-CA and increased with others. The FSA was increased with ACDF-AP, ACDF-CP, and ACCF, but ACDF-CA was decreased. At the final follow-up, the FSH was slightly decreased in ACDF-CP, ACDF-AP, and ACCF, but ACDF-CA was more decreased. Graft related complication were minimal. Screw loosening, plate fracture, cage subsidence and migration were not identified. Conclusion: ACDF-CP demonstrated a higher fusion rate and less minimal FSH loss than the other fusions in two-level cervical disc disease. The ACDF-AP and ACCF methods had a better outcome than the ACDF-CA with respect to GCL, FSA, and FSH.