• 한국구조물진단유지관리공학회 논문집
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• 제24권6호
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• pp.1-9
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• 2020

본 연구에서는 벽체의 록킹 거동을 고려한 내진보강 기법을 개발하였다. 록킹 거동은 벽체 수직 축을 중심으로 좌우로 회전하는 것으로, 개발 시스템은 변위 큰 부분에 댐퍼 등을 설치하여 에너지를 소산 시키는 방법이다. 댐퍼는 강봉 댐퍼를 사용하였으며, 강봉 지름 및 길이(형상비)를 변수로 선정하였다. 실험결과 댐퍼길이 260mm 경우 우수한 내진 성능을 보유한 것으로 평가되었다.

• 생명과학회지
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• 제19권10호
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• pp.1374-1381
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• 2009

본 연구는 남성 음주자의 나이대별 생리학적 변수들에 어떠한 차이가 있는지를 연구하였다. 30대 남성들은 waist-hip ratio, 좌 우 심장-발목 혈관지수, 좌 우 발목-상완지수, 아밀라제, hs-CRP, CPK가 가장 낮았고 체중, IL-6, 좌 우 안와혈압, 혈색소, 적혈구수, 적혈구 분포도, ALT, 총 콜레스테롤, 중성지방, 페르틴 농도는 높게 나타났다. hs-CRP, CPK는 40대 음주남성에서 높았지만 페리틴 농도는 반대였다. 50대 음주남성에서는 WHR이 높았으며 이완기 혈압, 좌 우 안와혈압, 호산구와 아밀라제 농도는 높게 나타냈다. 60대 음주남성에서는 좌 우 심장-발목 혈관지수, 평균 혈색소 농도, $\gamma$-GTP, RF, AFP, PSA의 농도는 높았으며, 체중, 이완기 혈압, 좌 우 안와혈압, 혈색소, 혈소판, 백혈구, 적혈구 분포지수, 호산구, 단구, 아밀라제 중성지방, CPK 농도 변화에서는 높게 나타났다. 이러한 결과를 볼 때 음주는 남성들에 있어 나이대별로 다양한 생리학적 변화를 유도 할 것으로 사료된다. 향후 음주가 성별, 즉 남녀 간에 미치는 생리학적 영향의 차이에 대한 연구 역시 더 필요할 것으로 생각된다.

• 한국도로학회논문집
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• 제15권5호
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• pp.123-133
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• 2013

PURPOSES : The present paper is to compare vehicles' $CO_2$ emissions in roundabouts and signalized intersections. METHODS : The present paper uses the SIDRA software with variables of traffic and road conditions. RESULTS : The results of the study are as follows : First, when entering traffic volumes are more than 1600pcph, vehicle's $CO_2$ emissions in roundabouts are lower than those of signalized intersections regardless of the left turn ratio. Second, When entering traffic volumes are more than 2800pcph, vehicles's $CO_2$ emissions in 2-lane approaches are lower than those of 1-lane approaches in signalized intersection. Third, when entering traffic volumes are more than 1600pcph, vehicle's $CO_2$ emissions of CASE B are lowest. (CASE B is the condition with one exclusive left-turn lane and one exclusive straight lane and one shared straight lane with right-turn.) Also, CASE A is the condition that vehicle's $CO_2$ emissions in roundabouts are lower than those of signalized intersections between 1600pcph and 3600pcph. (CASE A is the condition with one exclusive left-turn lane and one shared straight lane with right-turn.) But, when entering traffic volumes are more than 4000pcph, vehicle's $CO_2$ emissions in signalized intersections is lower than those of roundabouts. CONCLUSIONS : It may be concluded that vehicle's $CO_2$ emissions on roundabouts are much lower than those of signalized intersections, especially, when entering traffics volumes are between 1600pcph and 3600pcph in 1-lane or 2-lane approaches.

• 소음진동
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• 제8권2호
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• pp.336-345
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• 1998

The dynamic instability of cylindrical shell with clamped-free boundary condition subjected to constant follower force or $P_0 + P_1cos {\Omega}_t$ type pulsating follower force is analyzed. The motion of shell is modeled using the shell theory considering rotary inertia and shear deformation, and analyzed with finite element method. In case of constant follower force, the changes of eigenvalues dependent on the magnitude of applied load are investigated and the critical loads are obtained. In case pulsating follower force, instability regions of exicitation frequency are obtained by modal transform with right and left modal matrix and by multiple scales method. The effects of thickness ratio and aspect ratio on the instability of shell are studied.

• 치과방사선
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• 제7권1호
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• pp.5-8
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• 1977

The author has observed 906 full mouth roentgenograms in Korean young man who had the impacted and supernumerary teeth. Impacted and supernumerary teeth were analysed upon several items, such as incidences and positions in the dental arch. The result were as follows; 1. The incidences of impacted teeth were 59.05% and the ratio of upper jaw to lower one was 1:3. 2. The frequency of the supernumerary teeth were 5.52% and the ratio of maxilla to mandible was 49:1. 3. No significant differences between right and left side in both jaws, but incidence rate of the supernumerary teeth was 74% in the maxillary central incisor area. 4. The positions of impacted and supernumerary teeth were vertical and inverted shapes in maxilla, whereas horizontal and mesio-angular forms in mandible.

• 대한핵의학회지
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• 제31권3호
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• pp.365-371
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• 1997

The aim of this study is to evaluate the efficiency of the pulmonary perfusion scan(Pp scan) in the experimental animal single lung transplantation. Eight left lung transplanted mongrel dogs were included in this study. The serial Pp scan with 111MBq $^{99m}TC-MAA$ were done at the periods of immediate postoperative period, POD 3 days, and POD 10-14 days and finally autopsy was done in each cases. The transplanted lung perfusion was analysed as a percentage radioactivity of trans planted/native lung(T/N) ratio. The Pp scan of a donor mongrel dog was used as a reference(left/right lung (T/N) ratio 85.2%). The average T/N ratio of all cases on immediate postoperative state(reperfusion injury) : 19.2%, three acute rejections. 12.6%, three bronchial dehiscences 6.1% and two pulmonary thromboses : 2.0%. Two cases showed moderate improvement of reperfusion injury as increasing the T/N ratio in POD 3 days Pp scan. The T/N ratio showed sequentially decreased in six cases. As a conclusion, the Pp scan could be a non-invasive method in the evaluation of the experimental one-lung transplanted mongrel dog.

• Geomechanics and Engineering
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• 제32권2호
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• pp.193-207
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• 2023

In general, the numerous classical approaches available in the literature can anticipate the settlement of shallow foundations. As long as the footings are not in close proximity to other subsurface buildings, the findings achieved using these methods are legitimate and acceptable. However, due to increased urbanisation and land scarcity, footings are frequently built close together. As a result, these footings' settlement behaviour differs from those of isolated footings. A simpler approach for assessing the settlement behaviour of two square or rectangular footings placed in close proximity is presented in this work. A Parametric study has been carried out to examine the interference effect on the settlement of these footings placed in close vicinity on the surface of a homogeneous, isotropic and elastic soil medium. The interaction factors are examined by varying the different aspect ratios (L/B), clear spacing ratio (S/B) and intensity of loading on the right footing with respect to the left footing. Further, variation of the settlement ratio (δ/B) with respect to embedment depth ratio D_f/B is examined. For square and rectangular footings, the interference settlement profile is also investigated by varying the clear spacing ratio (S/B) and the degree of loading. The results were compared to 3D finite element analysis and experimental data that were available.

• Tuberculosis and Respiratory Diseases
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• 제38권4호
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• pp.340-346
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• 1991

Tuberculous tracheobronchitis is defined as a specific inflammation of the trachea or major bronchi caused by the tubercle bacillus and recognized as one of the most common and serious complication of pulmonary tuberculosis. It had been a diagnostic challenge in prebronchoscopic era and since 1968, fiberoptic bronchoscopy has been accepted as a safe and valuable diagnostic procedure of tuberculous tracheobronchitis. Now, it remains a troublesome therapeutic problem due to its sequelae such as bronchostenosis, bronchiectasis and bronchial deformity. The authors analyzed the clinical features, radiological findings and bronchoscopic findings with pathologic and bacteriologic study on 61 cases of tuberculous tracheobronchitis and following results were obtained. 1) The peak incidence was in the fourth decade and male to female ratio was 1:3.4. 2) The most common symptom was cough (86.9%) and followed by sputum (49.2%), dyspnea (27.9%), fever (19.8%), weight loss (11.5%), hemoptysis (6.6%), hoarseness (6.6%) and chest discomfort (3.3%) and localized wheezing was heard in 18%. 3) In chest X-ray, consolidation with collapse was observed in 70.5%, and followed by consolidation only (18.0%), mediastinal node enlargement (8.2%), cavitary lesion (6.6%), suspicious hilar mass (3.3%) and miliary lesion (1.6%) and there was no abnormal findings in 4.9%. 4) Bronchoscopy showed hyperplastic lesion in 67.2%, mucosal lesion (18.0%), ulcerative lesion (9.8%) and stenotic lesion (4.9%). The most common site of bronchial lesion was right upper bronchus (36.1%) and followed by right main bronchus (34.4%), left main bronchus (29.5%), left upper bronchus (16.4%), right middle bronchus (8.2%), right lower bronchus (6.6%) and left lower bronchus (3.3%). 5) Chronic granulomatous inflammation with or without caseation necrosis on microscopic examination was confirmed in 69.7%, bronchial washing AFB stain was positive in 34.1%, prebronchoscopic sputum AFB stain was positive in 88.1% and postbronchoscopic sputum AFB stain was positive in 30.1%.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.367-369
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• 2002

We have designed ramp profile excitation pulse based on the Shinnar-Le Roux (SLR) algorithm. The algorithm provides many advantages to pulse designers. The first advantage is the freedom of deciding the amplitudes, frequencies, and ripple sizes of stopband, passband, and transition band of pulse profile. The second advantage is the freedom of deciding the pulse phase, more specifically, minimum phase, linear phase, maximum phase, and any phase between them. The minimum phase pulse is the best choice in the case of 3D TOF, because it minimizes the echo time, which implies the best image quality in the same MR examination condition. In addition, the half echo technique is slightly modified in our case. In general, using the half echo technique means that the acquired data size is half and the rest part can be filled with complex conjugate of acquired data. But in our case, the echo center is just shifted to left, which implies the reduction of echo time, and the acquired data size is the same as the one without using the half echo technique. In this case, the increase of right part of data leads to improvement of the resolution and the decrease of left part of data leads to decrease of signal to noise ratio. Since in the case of 3D TOF, the signal to noise ratio is sufficiently high and the resolution is more important than signal to noise ratio, the proposed method appears to be significantly affective and gives rise to the improved high resolution angiograms.

• 한국방사선학회논문지
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• 제13권2호
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• pp.217-225
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• 2019

본 연구의 목적은 CT와 3.0T MRI 기기를 이용하여 간문맥을 묘출하는데 있어서 신호대 잡음비와 대조 도대 잡음비의 정량적인 수치를 비교 분석 하여 최적의 영상장치를 알아보고자 하였다. 2018년 2월부터 2018년 4월까지 C대학교병원에서 CT와 3.0T MRI 간 검사를 시행한 20명의 환자를 대상으로 의료영상저장전송시스템로 전송된 데이터를 무작위로 선정하였다. 정량적 평가를 위하여 간문맥의 4부위(주문맥, 우문맥, 좌문맥, 중간문맥)의 동일한 관심영역을 선정 후 신호평균값과 표준편차를 측정하여 SNR과 CNR값을 평가하였다. 평가결과 SNR은 CT에서 우문맥 : $9.18{\pm}0.72$, 좌문맥 : $9.41{\pm}0.84$, 중간문맥 : $9.54{\pm}0.59$, 주문맥 : $9.55{\pm}0.75$이고 3.0T MRI에서 우문맥 : $22.29{\pm}2.03$, 좌문맥 : $25.89{\pm}3.19$, 중간문맥 : $24.39{\pm}2.87$, 주문맥 : $26.64{\pm}2.30$으로 측정되었다(p<0.05). CNR은 CT에서 우문맥 : $3.75{\pm}0.66$, 좌문맥 : $3.44{\pm}0.65$, 중간문맥 : $3.71{\pm}0.39$, 주문맥 : $3.79{\pm}0.68$이고 3.0T MRI에서 우문맥 : $9.49{\pm}0.65$, 좌문맥 : $11.00{\pm}01.90$, 중간문맥 : $12.70{\pm}1.75$, 주문맥 : $10.01{\pm}0.98$으로 3.0T MRI가 CT보다 높은 수치로 측정되었다(p<0.05). 결론적으로 4부위의 간문맥을 분석한 결과 SNR과 CNR값이 3.0T MRI에서 높은 것으로 나타났다. 따라서 CT와 3.0T MRI에서 간문맥을 묘출하기 위한 최적의 영상장비는 비전리 방사선을 이용하는 3.0T MRI가 우위로 나타났다.