• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2002년도 춘계공동학술대회
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• pp.272-279
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• 2002

A common task in assembly modeling is the determination of the position and orientation of a set of components by solving the spatial relationships between them. Assembly models could be constructed at various levels of abstraction. They could be classified into component or geometry-level assembly models. The geometry-level assembly design approach using mating constraints such as against and fits is widely used in the commercial modelers, but it may be very tedious in some cases fur designer. In this paper, we propose a new method to construct an assembly model at the component-level by extracting joint mating features from the kinematics constraints specified between components. The assembly model constructed using the proposed method includes hierarchical and relational assembly models, component/sub-assembly positions and degrees of freedom information. The proposed method is more intuitive and natural way of assembly design and it guarantees the topological robustness of assembly modification such as component replacement and modification.

• 한방재활의학과학회지
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• 제26권2호
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• pp.51-59
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• 2016

Objectives We studied long-term preservation in stability of a mixed preparation of distilled and 70% alcohol extracted Hwangnyunhaedok-tang pharmacopuncture to establish standards for expiration date and quality control. Methods Three lots of consecutively prepared Hwangnyunhaedok-tang pharmacopuncture were each tested in triplicate to a total 5 tests at 3 month intervals over a period of 12 months for analysis of appearance, pH, specific gravity, index component content, endotoxins, microbial sterility, residual organic solvents, heavy metals, and pesticides. Items with no difference by elapsed time were tested at the initial and final timepoints, and data of items with potential difference by elapsed time were analyzed for trends to establish individual quality control standards. Results All tested items were stable over the study period, and therefore the expiration date was set as 12 months. pH quality control standards were set as 3.66~5.69, and that of specific gravity as 0.802~1.203, respectively. In index component content standards, berberine was set at $4.96{\sim}8.98{\mu}g/vial$, baicalin at $6.47{\sim}10.31{\mu}g/vial$, and geniposide at $116.03{\sim}189.55{\mu}g/vial$, respectively. Standards for other items with no difference by elapsed time were set according to general Korean herbal medicine standards in the Korean Pharmacopoeia. Conclusions Manageable expiration date and quality control standards were established through long-term preservation testing of Hwangnyunhaedok-tang pharmacopuncture, furthering standardization of Korean medicine pharmacopuncture.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2016년도 추계학술대회 논문집
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• pp.117-117
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• 2016

Total ankle replacement (TAR) is a visible option in the surgical treatment of degenerative or inflammatory diseases of ankle joint. it is attributed to the current TAR which has improvements in surgical technique, uncemented implant fixation and minimally constrained articulation. In the clinical result, they can show promised surgical result when compared to earlier attempts in TAR. However, TAR is still not as successful as total knee replacement (TKR) or total hip replacement (THR), it needs to be note that there are limitations in concerning of long term performance of TAR, the high failure rate still associated with wear of the PE (polyethylene) component that has related with their material property and surface roughness. The aim of this study was to introduce the tribology characteristics of total ankle joint prosthesis with one of TDR model which was fabricated to try multi-axis wear test as a region of motion in ankle joint. The wear specimen of TDR was prepared with Ti-6Al-4V alloy and UHMWPE (ultra-high molecular weight polyethylene) for tibia-talus and bearing component, respectively. A wear test was carried out using a Force 5 (AMTI, Massachusetts, US) wear simulator which can be allowed to move in three axis to flexion-extension ($+3^{\circ}{\sim}-6^{\circ}$), internal-external axial rotation (${\pm}5^{\circ}$), as well as sinusoidal compressive load (1.6 kN, R=10). All tests were performed following standard ISO 14243, wear rate was calculated with weight loss of UHMWPE bearing while the specimen has tested at certain cycles. As based on the preliminary results, wear rate of UHMWPE bearing was $7.9{\times}10^{-6}mg/cycles$ ($R^2=0.86$), calculated loss weight until $10^7cycles$ was 79 mg, respectively.

• Journal of the Korean Wood Science and Technology
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• 제30권4호
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• pp.96-105
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• 2002

전단벽은 현대식 경골목조건축에서 바람이나 지진 등에 의한 측방하중에 대한 저항력을 제공하는 가장 중요한 요소 중의 하나이다. 전단벽에서 건물에 전달된 측방하중은 벽의 스터드와 덮개재료 사이의 못접합부를 통하여 덮개재료로 전달되고 덮개재료에 전달된 하중은 판재의 면전단력에 의하여 지지된다. 따라서 실제 전단벽에서 측방하중에 대한 저항력을 결정하는 가장 중요한 요소는 못접합부라고 할 수 있을 것이다. 이 연구에서는 스터드와 판재 사이의 못접합부에 대한 강성 및 강도를 측정하였으며 이 값들은 전단벽의 찌그러짐 저항력을 예측하는 이론모형의 입력자료로 사용되었다. 이론모형의 예측치의 정확성을 검증하기 위하여 판재 한 장으로 구성된 전단벽의 전단시험을 수행하였다. 못접합부의 강성은 스터드 부재의 섬유방향에 의하여 영향을 받았으나 판재의 방향은 거의 영향을 미치지 않는 것으로 나타났다. 전단하중 하에서 못접합부나 전단벽의 거동은 3개의 직선구간으로 나나낼 수 있었으며 이론모형 I보다 이론모형 II의 예측치가 더 정확하였다.

• 항공우주시스템공학회지
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• 제17권6호
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• pp.108-117
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• 2023

지금까지 해외 수출용 KT-1 군용 고정익 항공기에 통합된 임무 소프트웨어는 해외업체와 국제 공동개발을 통하여 개발이 되었으며, 감항인증을 위해 DO-178B를 기반으로 하는 해외업체의 개발 환경과 절차를 준수함으로써 소프트웨어의 신뢰성을 인정받을 수 있었다. 하지만, 최근에는 해외 수출 시 DO-178C 인증을 요구하고 있으며, 국내 소요군에 납품 시 방사청 무기체계 소프트웨어 개발 및 관리 매뉴얼 준수를 위해 신뢰성 시험을 필수적으로 요구하고 있다. 본 논문은 기 개발된 KT-1 수출형 항공기 체계통합 사업의 국제 공동개발에 있어 국내 감항인증을 받기 위한 문제점을 기술하고 DO-178C와 무기체계 소프트웨어 개발 및 관리 매뉴얼을 모두 준수하기 위한 해결방안을 찾아서 최적의 소프트웨어 신뢰성 시험 방안을 제시한다.

• 근관절건강학회지
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• 제27권1호
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• pp.31-40
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• 2020

Purpose: This study was done to examine the effect of a multi-component cessation program on bone union by comparing the union time between the experimental group and the control group. Methods: A non-equivalent control group posttest design was used. The subjects were 33 patients in the experimental group and 33 patients in the control group, 66 patients in total. The subjects of the experimental group were provided with a face-to-face multi-component smoking cessation program. After the discharge, telephone consultation was provided once a week for 10 weeks. Results: Bone union time was 51.6±10.9 days in the experimental group and 60.9±13.83 days in the control group (p=.003). Among 33 subjects who participated in the smoking cessation program, the average union period of the participants who succeeded in quitting smoking was 44.56 days, the participants who reduced smoking were 50.67 days, and failed to quit smoking group was 60.11 days (p=.006). Conclusion: This study indicated the importance of smoking cessation in patients with fracture and the decrease in the union time by providing smoking cessation education. If the multi-component smoking cessation program is used as a nursing intervention in clinical practice, it will be effective for bone union by increasing the smoking cessation rate of patients with fracture.

• 한국음향학회지
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• 제38권2호
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• pp.177-183
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• 2019

본 논문에서는 수동 선배열 소나의 저주파 영역에서 수신된 표적 신호로부터 간섭신호를 분리해 내기 위해 독립성분분석 알고리즘을 적용하는 방안을 제안하고 기존 알고리즘들의 성능을 비교해 보았다. 저주파 대역 신호의 경우 비교적 넓은 방위로부터 수신되기 때문에 인접 빔 신호를 관측신호로 활용하여 독립성분분석을 수행할 수 있다. 신호분리에 사용한 독립성분분석 알고리즘은 FastICA(Fast Independent Component Analysis), NNMF (Non-negative Matrix Factorization), JADE (Joint Approximation Diagonalization of Eigen-matrices)이다. 실측 선배열 수동소나신호를 이용하여 독립성분분석을 수행한 결과 제안한 방법으로 간섭신호분리가 가능함을 확인하였으며, JADE 알고리즘의 신호 분리 성능이 가장 우수한 것으로 나타났다.

• Steel and Composite Structures
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• 제38권6호
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• pp.637-656
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• 2021

The component-based method is widely used to analyze the initial stiffness of joint in steel structures. In this study, an analytical component model for determining the column face stiffness of square or rectangular hollow section (SHS/RHS) subjected to tension was established, focusing on endplate connections. Equations for calculating the stiffness of the SHS/RHS column face in bending were derived through regression analysis using numerical results obtained from a finite element model database. Because the presence of bolt holes decreased the bending stiffness of the column face, this effect was calculated using a novel plate-spring-based model through numerical analysis. The developed component model was first applied to predict the bending stiffness of the SHS column face determined through tests. Furthermore, this model was incorporated into the component-based method with other effective components, e.g., bolts under tension, to determine the tensile stiffness of the T-stub connections, which connects the SHS column, and the initial rotational stiffness of the joints. A comparison between the model predictions, test data, and numerical results confirms that the proposed model shows satisfactory accuracy in evaluating the bending stiffness of SHS column faces.

• Journal of the Korean Data and Information Science Society
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• 제8권2호
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• pp.195-209
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• 1997

일반화 선형모형의 범위를 크게 확장한 준-우도 모형에서 반응변수의 분산성분인 산포모수가 상수가아니라 어떤 공변량들의 값에 의존하여 변하는 경우, 평균과 산포의 동시 모형화가 요구된다. 본 논문에서는 준-우도 모형에서 평균과 산포의 동시 모형화를 통해 실제 자료를 쉽게 분석하도록 해주는 통계 패키지 GENSTAT(release 5.3.2, 1996)을 활용하여, Carrol과 Ruppert(1987,pp.46-47)에 의해 소개된 에스테르 분해효소 (esterase assay)의 자료에 대해 그래픽 방법을 이용한 모형검토를 통해서 기존의 평균모형 보다는 평균과 산포의 동시 모형화를 고려해야 하는 필요성을 언급한 뒤, 그 자료에 대한 적절한 평균과 산포의 동시 모형을 찾는 방법을 연구한다.

• Structural Engineering and Mechanics
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• 제29권1호
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• pp.17-35
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• 2008

Neglecting the real joint behaviour in frame analysis may result in unrealistic predictions of the response and reliability of steel frames. The reliability of the prediction of main joint properties according to the component method (Eurocode 3-Part 1.8) still remains open to further investigation. The first step toward the solution is to compare the theoretical expressions given in EN 1993-1-8 and the experimental results. With that goal in mind six nominally the same, but really different specimens of welded beam-to-column joints subjected to static load were tested. The specimens present a combination of nominally identical structural elements produced in different European mills. This paper provides these tests, as well as their detailed evaulation and interpretation. All three joint structural properties (rotational stiffness, moment resistance and rotation capacity) have been considered. Four models for determining the plastic resistance out of experimental Mj-${\phi}$ curves have been applied. The results that have been discussed in detail, point to the fact that EN 1993-1-8 underestimates the real structural properties of the tested type of joint, as well as to the conclusion that detailed research of this problem needs to be conducted using the probabilistic reliability methods.