• 한국산학기술학회논문지
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• 제16권7호
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• pp.4849-4854
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• 2015

본 논문은 2004년 경부고속선 개통이후 UM71C AF궤도회로 현장 구성품(BU, SVaC, DB)들이 선로내측 자갈도상에 설치되어 있기 때문에 겨울철 고속차량 낙빙 및 시설분야 장비작업으로 인한 파손사례가 자주 발생되어 시설물 보호를 위한 개선대책일환으로 선로내측에 설치된 구성품을 선로외측으로 이설할 경우 케이블 길이 변화에 따른 임피던스 특성변화와 보상콘덴서 추가구성을 위하여 MATLAB Simulink를 이용하여 시뮬레이션을 시행하였고 또한 고속선 현장실증시험을 통하여 시뮬레이션과 동일한 결과를 얻었다. 향후 궤도회로사구간에 대한 보완과 구성품내부 임피던스 재설계 연구를 통하여 실제 현장에 적용될 수 있을 것으로 기대된다.

• Clinical Pain
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• 제18권1호
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• pp.8-15
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• 2019

Objective: To determine the relationship between cervical sagittal parameters and the degree of the cervical disc degeneration at each cervical level by using cervical plain radiographs and disc degeneration grading. Method: This study analyzed 110 patients with posterior neck pain. Cervical radiographic measurements included the occipito-cervical (O~C2) angle; sagittal Cobb angles of C1~C2, C2~C7; and sagittal vertical axis (SVA) of C1~C7 and C2~C7. The degenerations of cervical discs at each level were evaluated through Pfirrmann grading system by magnetic resonance images of the cervical spine. The correlations between the cervical sagittal measurements and the disc degeneration at each level were analyzed by Spearman's correlation. Results: A significant correlation was found for the C2~C7 angle with disc degenerations at C2~C6 levels. O~C2 angle was correlated significantly with disc degenerations at C2~C4 and C5~C7 levels. There was significant correlation between C1~C2 angle and disc degeneration at C6~C7 level. No significant relationship was found between the cervical SVA and the cervical disc degeneration at all cervical levels. Conclusion: Cervical sagittal parameters representing cervical angles (C2~C7, O~C2, and C1~C2 angles) were significantly correlated with the degree of the cervical disc degeneration. These findings suggest that the loss of the natural cervical lordosis rather than loss of natural SVA could be correlated with progression of the cervical disc degeneration.

• Journal of Acupuncture Research
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• 제27권2호
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• pp.97-104
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• 2010

Objectives : The authors aimed to determine the presence of relationships between cervical pain and cervical curvature, lumbar curvature, sacral slope and sagittal spinal balance. Methods : Medical records of outpatients who made their first visits to the Department of Acupuncture and Moxibustion in the Spine center at Kyung Hee East-West Neo Medical Center between September 1, 2008 and October 31, 2009 were evaluated. A total of 50 patients visiting within the time period had visited with a chief complaint of cervical pain, and had lateral entire spine X-rays taken. After excluding patients with previous spine operations, 46 patients were selected for the final analysis. The cervical lordotic angle(CLA), lumbar lordotic angle(LLA), Ferguson's angle(FA), and sagittal vertical axis(SVA) were measured on the lateral entire spine X-ray cuts, and the relationships between these values and patient gender, age, chief complaint, and duration of symptoms were assessed. Results : No significant difference was found in relationships between gender and measured values. SVA showed statistically significant correlation between age, but CLA, LLA, and FA was not. There was a significant difference in SVA between patients with only cervical pain and those with both cervical pain and low back pain. Patients with a duration of symptoms longer than 6 months showed a statistically significant difference in SVA with those who had shorter symptoms. Correlation analysis between measured values was statistically significant only between LLA and FA. Conclusions : Evaluation and treatment of sagittal imbalance should be considered in patients presenting with cervical pain if symptoms have persisted for over 6 months or have accompanying low back pain.

• Journal of Korean Neurosurgical Society
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• 제60권5호
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• pp.577-583
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• 2017

Objective : Laminoplasty is an effective surgical method for treating cervical degenerative disease. However, postoperative complications such as kyphosis, restriction of neck motion, and instability are often reported. Despite sufficient preoperative lordosis, this procedure often aggravates the lordotic curve of the cervical spine and straightens cervical alignment. Hence, it is important to examine preoperative risk factors associated with postoperative kyphotic alignment changes. Our study aimed to investigate preoperative radiologic parameters associated with kyphotic deformity post laminoplasty. Methods : We retrospectively reviewed the medical records of 49 patients who underwent open door laminoplasty for cervical spondylotic myelopathy (CSM) or ossification of the posterior longitudinal ligament (OPLL) at Pusan National University Yangsan Hospital between January 2011 and December 2015. Inclusion criteria were as follows : 1) preoperative diagnosis of OPLL or CSM, 2) no previous history of cervical spinal surgery, cervical trauma, tumor, or infection, 3) minimum of one-year follow-up post laminoplasty with proper radiologic examinations performed in outpatient clinics, and 4) cases showing C7 and T1 vertebral body in the preoperative cervical sagittal plane. The radiologic parameters examined included C2-C7 Cobb angles, T1 slope, C2-C7 sagittal vertical axis (SVA), range of motion (ROM) from C2-C7, segmental instability, and T2 signal change observed on magnetic resonance imaging (MRI). Clinical factors examined included preoperative modified Japanese Orthopedic Association scores, disease classification, duration of symptoms, and the range of operation levels. Results : Mean preoperative sagittal alignment was $13.01^{\circ}$ lordotic; $6.94^{\circ}$ lordotic postoperatively. Percentage of postoperative kyphosis was 80%. Patients were subdivided into two groups according to postoperative Cobb angle change; a control group (n=22) and kyphotic group (n=27). The kyphotic group consisted of patients with more than $5^{\circ}$ kyphotic angle change postoperatively. There were no differences in age, sex, C2-C7 Cobb angle, T1 slope, C2-C7 SVA, ROM from C2-C7, segmental instability, or T2 signal change. Multiple regression analysis revealed T1 slope had a strong relationship with postoperative cervical kyphosis. Likewise, correlation analysis revealed there was a statistical significance between T1 slope and postoperative Cobb angle change (p=0.035), and that there was a statistically significant relationship between T1 slope and C2-C7 SVA (p=0.001). Patients with higher preoperative T1 slope demonstrated loss of lordotic curvature postoperatively. Conclusion : Laminoplasty has a high probability of aggravating sagittal balance of the cervical spine. T1 slope is a good predictor of postoperative kyphotic changes of the cervical spine. Similarly, T1 slope is strongly correlated with C2-C7 SVA.

• 한국심리학회지:법
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• 제12권2호
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• pp.121-149
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• 2021

진술의 진실성을 평가하는 절차인 진술타당도분석(Statement Validity Analysis: SVA)은 국내외 범죄 수사와 법정 상황에서 활용되고 있다. SVA 절차 중 내용분석 단계에서는 준거기반내용분석(Criteria-Based Content Analysis: CBCA) 준거를 사용하여 진술에서 실제 경험에 기반하였을 때 나타나는 특징들이 현출되는지를 평가한다. CBCA 준거의 변별력과 효과크기에 대한 국내 연구는 다양한 패러다임으로 이루어졌지만, 그 연구 결과들의 일관성은 여전히 검증되지 않았다. 이에 본 연구에서는 국내에서 관련 연구가 시작된 2004년부터 2020년까지 수행된 CBCA 준거 관련 연구들(14개의 연구자료)에 대한 메타분석을 실시하였다. 연구결과, CBCA 총점이 진실과 작화를 성공적으로 변별해내고 있었다. 준거별로는, 네 개의 준거(3번, 4번, 10번, 12번; 모두 인지적 준거)에서 정적(+)인 효과크기가 유의미했다. 그러나 18번 준거(동기적 준거)는 CBCA의 기본 가정과는 반대로, 효과크기가 부적(-)으로 유의미한 것으로 나타났다. 또한, 조절효과분석이 가능한 열한 개의 준거(2번~9번, 12번, 13번, 15번) 각각에 대해 잠재적 조절변인의 영향을 살펴본 결과, 일부 준거들에 대하여 진술인의 성별 및 신분, 연구 유형 및 설계, 사건 유형, 평가자 수, 출판 여부의 조절효과가 유의미한 것으로 나타났다. 따라서 본 연구결과는 진실여부를 타당하게 판단하기 위해서는 CBCA 총점보다는 세부 준거, 특히 인지적 준거에 초점을 맞추는 것이 중요하며, 잠재적 조절변인의 영향 가능성 또한 중요하게 고려해야 함을 시사한다. 관련하여 본 연구의 의의, 제한점 및 추후 연구 방향에 대해 논하였다.

• 인터넷정보학회논문지
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• 제14권4호
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• pp.43-51
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• 2013

고도의 보안 시스템에서 사용자 인증과 접근제어는 두 가지 중요한 요소이다. 최근 Chen & Yeh는 이 두 가지 보안 요소를 원활하게 잘 통합한 방법을 제안하였다. 그러나 Chen-Yeh 방법은 원격 서버에 스마트 카드 ID 자료를 유지하기 때문에 SVA(stolen verifier attack: 도난 검증자 공격)에 취약하다는 단점을 가지고 있다. 따라서 본 논문에서는 Chen & Yeh 방법의 이런 단점을 개선하고, 장점은 그대로 유지하는 새로운 사용자 인증 및 접근제어 방법을 제안한다. 보안 분석 결과에 의하면, 기존 방법들에 비하여 제안 방법은 여러 가지 다양한 보안 침해 공격에 강인하면서, 사용자 인증 및 접근제어에 도움이 되는 많은 좋은 특징을 보유하고 있는 것으로 입증되었다.

• Journal of Korean Neurosurgical Society
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• 제61권2호
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• pp.251-257
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• 2018

Objective : The aim of this study was to investigate clinical and radiological outcomes of patients who underwent posterior vertebral column resection (PVCR) by a single neurosurgeon in a single institution. Methods : Thirty-four consecutive patients with severe spinal deformities who underwent PVCR between 2010 and 2016 were enrolled. The radiographic measurements included a kyphotic angle of PVCR levels (VCR angle), sagittal vertical axis (SVA), thoracic kyphosis, lumbar lordosis (LL), and spinopelvic parameters. The data of surgical time, estimated blood loss, duration of hospital stay, complications, intraoperative neurophysiologic monitoring, and the Scoliosis Research Society (SRS)-22 questionnaire were collected using a retrospective review of medical records. Results : The VCR angle, LL, and SVA values were significantly corrected after surgery. The VCR and LL angle were changed from the average of $38.4{\pm}32.1^{\circ}$ and $-22.1{\pm}39.1^{\circ}$ to $-1.7{\pm}29.4^{\circ}$ (p<0.001) and $-46.3{\pm}23.8^{\circ}$ (p=0.001), respectively. The SVA was significantly reduced from $103.6{\pm}88.5mm$ to $22.0{\pm}46.3mm$ (p=0.001). The clinical results using SRS-22 survey improved from $2.6{\pm}0.9$ to $3.4{\pm}0.8$ (p=0.033). There were no death and permanent neurological deficits after PVCR. However, complications occurred in 19 (55.9%) patients. Those patients experienced a total of 31 complications during- and after surgery. Sixteen reoperations were performed in twelve (35.3%) patients. The incidence of transient neurological deterioration was 5.9% (two out of 34 patients). Conclusion : Severe spinal deformities can be effectively corrected by PVCR. However, the PVCR technique should be utilized limitedly because surgery-related serious complications are relatively common.

• Journal of Korean Neurosurgical Society
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• 제63권5호
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• pp.623-630
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• 2020

Objective : A primary degenerative sagittal imbalance has been considered because of unique lifestyles such as the prolonged crouched posture during agricultural work and performing activities of daily living on the floor. Previous papers have reported that sagittal imbalance disease is often seen distinctly in the farming districts of "oriental" countries such as Korea and Japan. However, this finding was only evaluated with the use of X-ray, and other factors such as magnetic resonance imaging (MRI), muscle volume, compression fracture, and laboratory results were not considered. Thus, using these, we evaluate the agricultural work-associated factors for Korean elderly spinal sagittal imbalance. Methods : We recruited 103 Korean participants who had a sagittal vertical axis (SVA) of >5 cm in this Korean Elderly Sagittal Imbalance Cohort Study. The following were evaluated : radiological parameters, MRI, compression fracture, vitamin D, parathyroid hormone, C-terminal telopeptide, osteocalcin, bone mineral density and muscle fatty change, muscle volume, and health-related quality of life from patients' survey. Moreover, in this survey, the farmers' annual working hours were investigated. Subsequently, we analyzed the associated factors for spinal sagittal imbalance depending on occupation. Results : A total of 46 participants were farmers, and the others were housewives, sellers, and office workers. The farmer group had more SVA (141 vs. 99 mm, p=0.001) and pelvic tilt (31° vs. 24°, p=0.004) and lesser lumbar lordosis (20° vs. 30°, p=0.009) and thoracic kyphosis (24° vs. 33°, p=0.03) than non-farmer group. A significantly positive correlation was noted between the working hour and SVA in the farmer group (p=0.014). The visual analogue scale score for back pain (8.26 vs. 6.96, p=0.008) and Oswestry Disability Index (23.5 vs. 19.1, p=0.003) in the farmer group were higher than that in the non-farmer group, but the Short Form-36 score was not significantly different between the two groups. The Mini-Mental State Exam score was significantly lower in the farmer group than in the non-farmer group (24.85 vs. 26.98, p=0.002). Conclusion : The farmer group had more sagittal imbalance and back pain in proportion to the working hours even though the muscle and bone factors and general laboratory condition were not significantly different between the two groups. These results supported that the long hours spent in the crouched posture while performing agricultural work were a risk factor for severe sagittal imbalance.

• 대한조선학회논문집
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• 제54권3호
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• pp.215-226
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• 2017

This paper presents numerical results of the performance of a marin propeller in cavitating and non-cavitating flow conditions. The geometry and experimental validation data of the propeller are provided in Potsdam Propeller Test Case(PPTC) in the framework of the second International Symposium on Marine Propulsors 2011(SMP'11) workshop. The PPTC includes open water tests, velocity field measurements and cavitation tests. The present numerical analysis was carried out by using the Reynolds averaged Navier-Stokes(RANS) method on a wall-resolved grid ensuring a y+=1, where the SST k-${\omega}$ model was mainly used for turbulence closure. The influence of the turbulence model was investigated in the prediction of the wake field under a non-cavitating flow condition. The propeller tip vortex flows in both cavitating and non-cavitating conditions were captured through adaptation of additional grids. For the cavitation flows at three operation points, Schnerr-Sauer's cavitation model was used with a Volume-Of Fluid(VOF) approach to capture the two-phase flows. The present numerical results for the propeller wake and cavitation predictions including the open water performance showed a qualitatively reasonable agreement with the model test results.

• 한국콘텐츠학회논문지
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• 제16권11호
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• pp.614-622
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• 2016

오늘날 매체가 다양해짐에 따라, 애니메이션의 영역도 확장되고 있다. 이전에는 볼 수 없었던 여러 유형의 애니메이션이 등장하고, 모션그래픽 애니메이션, 인터렉티브 애니메이션 등과 같이 '애니메이션'이라는 접미사를 가지지 않았던 영역들도 애니메이션 이라는 단어를 사용하고 있다. 본 논문은 미국 애니메이션 교육에 대한 비교 분석 연구이다. 1961년 처음 대학에 애니메이션 교육이 도입된 이래 미국 애니메이션 교육을 이끌어오고 있는 아트 아카데미 대학교(Academy of Art University), 캘리포니아 예술 대학(California Art of Institute), 링글링 디자인 대학(Ringling College of Art and Design), 로드아일랜드 디자인 학교(Rhode Island School of Design), 시각 예술 학교(School of Visual Arts) 총 5개 대학을 대상으로 교육과정을 수집하고, 각각의 내용을 검토하였다. 애니메이션 교육과정을 전공 필수과목, 전공 선택과목, 교양과목으로 나누어 분석한 결과를 통해 한국의 애니메이션 교육과정의 개선점에 대하여 고찰해보고자 한다.