• 한국기계가공학회지
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• 제19권7호
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• pp.81-88
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• 2020

The geometry and the defect of the groove of the part provoke a sudden change of stress in a local region. The objective of this paper is to investigate the effects of the geometry and the imperfection of a small groove on stress distributions in the vicinity of the joined region for the ABS part with a thin wall using a three-dimensional finite element analysis (FEA). Several types of groove are designed to improve joining characteristics in the vicinity joined region. The imperfection model of the small-sized groove is obtained from observation of deposition characteristics of a fused deposition modeling process. Local stress distributions in the vicinity of the joined region are predicted by the FE model with refined meshes. The influence of the angle and the imperfection of the groove on appearance regions of the maximum stress and distributions of the defined principal stress for different loading conditions is examined using the results of FEAs. Finally, a proper design of the groove is proposed to improve joining characteristics between the substrate and the ABS part.

• 산경연구논집
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• 제11권3호
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• pp.51-62
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• 2020

Purpose - This study examined the relationship between individual creativity and its related variables to observe how individual creativity contributes to organizational performance. In addition, this study strived to explore how to maximize the utilization of individual creativity and innovate the structure of the organization itself so that teams and organizations can respond more effectively to new rising trends. this study aimed to examine whether the value congruence between individuals and organizations (propensity congruence, goal congruence has a significant impact on knowledge sharing and innovation behavior as dependent variables by exerting individual creativity and synergy as independent variables. Research design, data and methodology - SPSS 24.0 program were used to analyze the data. Descriptive Statistics and correlation analysis were performed, and the reliability factor (Cronbach's α) was calculated. Afterwards, we analyzed the moderating effects of structural equation model analysis and hierarchical regression analysis. The number of samples used in the study were 309 copies. Results - First, Individual creativity had a positive effect on knowledge sharing and innovative behavior. In other words, it was confirmed that decision-making processes fused with individual creativity could create an atmosphere of knowledge sharing and transform the organization. Second, value congruence adjusted the influence of individual creativity on knowledge sharing and innovation behavior. Conclusions - First, it is important for managers to recognize the value and secure the pool of creative talents who will be a potential future basic source of organizational success and competitive advantage. Second, managers should be able to identify those with creative talents and expertise, and use them to increase their knowledge sharing performance, while also developing emotional and motivational creativity. Third, in order improve knowledge sharing performance, managers should pay attention to the emotional aspect of creativity. Fourth, managers should strive to create an environment that is beneficial for the reinforcement of individual self-management capabilities. Fifth, managers should be able to develop decision-making processes to develop potential creativity and encourage creative thinking, opinions, or solutions. Sixth, managers should promote the dissemination and integration of new knowledge based on the creative views and attitudes of team members.

• 한국항행학회논문지
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• 제22권5호
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• pp.456-461
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• 2018

4차 산업혁명을 통해 웹이 다양한 기술들과 융합되기 전에는 웹 애플리케이션의 성능을 평가하는 요소가 단순히 웹 애플리케이션이 로딩 되는 속도뿐이었다. 따라서 기존에 시중에 나와 있는 웹 애플리케이션 성능분석 툴의 경우 대부분 웹 애플리케이션이 웹 브라우저에서 동작 하는 속도에 초점을 맞추고 있다. 하지만 웹은 이제 단순 웹 브라우저 뿐만 아니라 다양한 서비스들과 융합되어 활용되고 있으며, 단순 속도 이외에도 웹 애플리케이션을 평가하기 위해 평가해야할 요소들이 등장했다. 따라서 본 논문에서는 앞서 언급한 속도뿐만 아니라 프로그레시브 웹 앱, 접근성, 모범 사례, 검색 엔진 최적화를 고려한 웹 애플리케이션 성능 분석을 진행하기 위한 서버를 설계하고, REST API 형태로 서비스를 구축하여 사용자의 기기나 환경에 영향을 받지 않고 웹 애플리케이션 성능 서비스를 제공할 수 있는 서버를 설계 및 구현하고자 한다.

• 생명과학회지
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• 제17권2호통권82호
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• pp.179-184
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• 2007

단백질 티로신 kinase인 PTK6는 대부분의 유방암에서 과발현되며, 암세포의 증식만을 촉진하는데 역할을 한다. 이 연구에서 PTK6의 활성도메인을 초파리의 peptidoglycan recognition protein (PGRP) -LB 단백질을 퓨전파트너로 사용하여 바큘로바이러스 시스템을에서 과발현하는데 성공하였다. 우리는 PGRP-LB가 바큘로바이러스 시스템에서 잠재적으로 퓨전 단백질로 사용될 수 있는 가능성을 처음으로 발견하였다. 정제된 PTK6단백질은 기존의 박테리아에서 발현된 단백질보다 1.5배 높은 활성을 지녔다. 이 단백질은 PTK6의 분자기전 및 그것의 저해제 개발에 필수적인 결정 구조를 규명하는데 사용될 것이다.

• 서비스연구
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• 제2권2호
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• pp.45-51
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• 2012

U-Healthcare는 홈 네트워크, 휴대용 장치 등에 기반한 정보통신기술과 의료시스템이 서로 융합되어 개인의 생체정보 등을 실시간으로 모니터링하고, 자동으로 병원 및 의사와 연결되어 시공간의 제약을 줄임으로써 언제 어디서나 건강을 관리하고 질병을 예방하는 새로운 형태의 의료서비스이다. 본 논문에서는 진료 중심에서 예방 중심으로 변화되어가고 있는 최근의 U-Healthcare 시스템의 기술 발전 추세에 맞추어 조기 대응이 가능한 Healthcare 정보시스템 구축을 위한 요구분석 사항들에 대해 정리하고, 이를 기반으로 u-Healthcare의 실현을 위한 기존의 단위 시스템인 PACS, OCS, EMR, 응급의료시스템을 통합한 환자중심의 클라이언트 시스템을 설계한다. 특히, 온톨로지는 특정분야의 정보 모델에 이용되어 그 분야에서 공통의 어휘를 제공하고, 그 용어의 의미와 용어간의 관계를 다양한 수준의 형식성을 가지고 제공한다. 본 논문에서는 이러한 온톨로지 및 무질서한 데이터에 대한 관계를 정의하고, 보다 체계적으로 데이터를 군집화하는 클러스터링의 개념을 포함한 환자중심의 서비스를 위한 온톨로지 기반의 시스템을 제안한다.

• 한국재료학회지
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• 제27권4호
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• pp.206-210
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• 2017

In this study, an ${\alpha}-Fe_2O_3$ (hematite) coated porcelain plate was sintered in a temperature range from $1100^{\circ}C$ to $1250^{\circ}C$ using ferrous sulfate. The specimens were investigated by X-ray diffractometer (XRD), scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), and UV-visible spectrophotometer. It was confirmed that ${\alpha}-Fe_2O_3$ (hematite) was densely fused to the surface at several tens of ${\mu}m$, the ${\alpha}-Fe_2O_3$ (hematite) was in the form of thin platelet and polyhedra, and no other compounds appeared in the sintering process. In the specimen coated with ${\alpha}-Fe_2O_3$ (hematite), the reflectance spectra show a red absorption band of 560-650 nm. The $L^*$ value decreased from 53.18 to 46.94 with the firing temperature. The values of $a^*$ and $b^*$ were at 19.03 and 15.25 at $1100^{\circ}C$ and gradually decreased with increasing temperature; these values decreased rapidly at $1250^{\circ}C$ to 11.54 and 7.98, respectively. It is considered that the new phases are formed by the phase transition of the porcelain plate (clay), and thus the $a^*$ and $b^*$ values are greatly influenced.

• 융합정보논문지
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• 제7권2호
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• pp.53-58
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• 2017

본 논문은 상관형 위상비교(correlative interferometer) 방향탐지 장치의 정확도 분석용 시뮬레이터 설계에 대하여 기술하였다. 상관형 위상비교 방향탐지는 잡음에 강인하므로 안테나 설치가 복잡한 항공기나 함정 등에서 많이 사용되며 방향탐지 정확도가 매우 높다. 또한 전파가 특정 방위각에서 입사될 때 잡음이 없는 환경에서 계산한 위상차와 잡음이 있는 실제 환경에서 측정한 위상차를 융합하여 상관계수가 가장 큰 값을 전파의 방위각으로 추정하는 방식이다. 시뮬레이터는 전파의 주파수, 방탐장치 안테나 수, 안테나 좌표, 전파의 송신신호 세기, 수신기의 대역폭, 이득, 플랫폼(platform)의 전파간섭 등을 입력으로 받아서 0-360도 방위각과 0-60도 고각에 대한 방향탐지 정확도를 계산한다. 시뮬레이터는 실제 환경에서 발생할 수 있는 요소를 대부분 반영하였으므로 방향탐지 오차 분석이 0.5도 이하로 정확하고 함정과 항공기의 방탐장치 설계에 잘 활용할 수 있을 것으로 판단된다.

• 분석과학
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• 제34권4호
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• pp.143-152
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• 2021

Capillary electrophoresis (CE) is an effective technique to study chiral recognition because it offers flexibility in adjusting vital factors. Currently, various available cyclodextrins (CDs) can be employed for the chiral separation of numerous analytes. Herein, we investigate the enantioseparation behavior of lipoic acid enantiomers in various types of single and dual CD systems through CE. Additionally, several impacted CE parameters were optimized through the systematic investigation based on the design of experiment (DoE) concept for a single system comprising a heptakis (2,3,6-tri-O-methyl)-β-CD and a dual system containing the combination of the single CD with a sulfated-β-CD. Consequently, absolute enantioresolution was obtained within 15 min on a common standard bare fused-silica capillary (64.5/56 cm in total/effective length, 50/365 ㎛ inner/outer diameter), maintained at 15 ℃ and at an applied voltage of 24 kV. The optimal background electrolyte consisted of 6 mM heptakis (2,3,6-tri-O-methyl)-β-CD dissolved in the solution of 58 mM borate buffer at pH 10. Furthermore, the results of apparent binding constant experiments indicated that the S-enantiomer-heptakis (2,3,6-tri-O-methyl)-β-CD complex exhibited a stronger affinity than its R-enantiomer counterpart. The obtained electrophoretic mobility values could be utilized to interpret the resolution achieved at various CD concentrations and the mobility behavior of the complexes elucidated the migration order of the enantiomers in an electropherogram.

• Asian Spine Journal
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• 제12권6호
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• pp.1078-1084
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• 2018

Study Design: Prospective observational study. Purpose: This prospective analysis aimed to evaluate the efficacy and bone-bonding rate of hybrid hydroxyapatite (HA) spacers in expansive laminoplasty. Overview of Literature: Various types of spacers or plates have been developed for expansive laminoplasty. Methods: Expansive open-door laminoplasty was performed in 146 patients with cervical myelopathy; 450 hybrid HA spacers and 41 autogenous bone spacers harvested from the spinous processes were grafted into the opened side of each lamina. The patients were followed up using computed tomography (CT), and their bone-bonding rates for hybrid HA and autogenous spacers, bone-fusion rates of the hinges of the laminae, and complications associated with the implants were then examined. Results: Clinical symptoms significantly improved in all patients, and no major complications related to the procedure were noted. The hybrid HA spacers exhibited sufficient bone bonding on postoperative CT. The hinges completely fused in over 95% patients within 1 year of the procedure. Only 4 spacers (0.9%) developed lamina sinking, and most expanded laminae maintained their positions without sinking or floating throughout the follow-up period. Conclusions: Hybrid HA spacers contributed to high bone-fusion rates of the spacers and hinges of the laminae, and no complications were associated with their use. Cervical laminoplasty with these spacers is safe and simple, and it yields sufficient fixation strength while ensuring sufficient bone bonding during the immediate postoperative period.

• 대한방사선기술학회지:방사선기술과학
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• 제41권6호
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• pp.595-602
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• 2018

Quality control (QC) of Computed Tomography (CT) devices is based on image quality measurement on AAPM CT phantom which is a standard phantom. Although it is possible to control the accuracy of the CT apparatus, it is expensive and has a disadvantage of low penetration rate. Therefore, in this study, we make image quality measurement phantom at low cost using FFF (Fused Filament Fabrication) type three-dimensional printer and try to analyze the usefulness, compare it with existing standard phantom. To print a phantom, We used three-dimensional printer of the FFF system and PLA (Poly Lactic Acid, density: $1.24g/cm^3$) filament, and the CT device of 64 MDCT (Aquilion CX, Toshiba, Japan). In addition, we printed a phantom using three-dimensional printer after design using various tool based on existing standard phantom. For image quality evaluation, AAPM CT phantom and self-generated phantom were measured 10 times for each block. The measured data were analyzed for significance using the Mannwhiteney U-test of SPSS (Version 22.0, SPSS, Chicago, IL, USA). As a result of the analysis, phantom fabricated with three-dimensional printer and standard phantom showed no significant difference (p>0.05). Furthermore, we confirmed that image quality measurement performance of a phantom using three-dimensional printer is similar to the existing standard phantom. In conclusion, we confirmed the possibility of low cost phantom fabrication using three dimensional printer.