• Journal of Microbiology and Biotechnology
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• 제14권4호
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• pp.707-714
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• 2004

How to improve the cell culture method on scaffolds is important in the tissue engineering fileld. In this study, we optimized seeding and culture methods to vascular smooth muscle cells (VSMCs) on biodegradable polymer scaffold. The primary culture of VSMCs obtained from canine external jugular vein was accomplished by applying the explant-derived method. The primary cultured VSMCs were seeded into scaffolds and then cultured by using various different methods; static or dynamic seeding, static or dynamic culture. The difference in proliferative response of VSMCs was analyzed with an alamar blue assay. Cell-polymer construct was examined by histochemical method and scanning electron microscopy. Mesh type scaffold ($10 \times 10 \times0.4 mm$) was made of polyglycolic acid (PGA) suture thread. The PGA mesh type scaffold was 45% in porosity, and 0.03 g in weight. The primary cultured VSMCs were confirmed with immunohistochemical staining using monoclonal anti-$\alpha$-smooth muscle actin. The density and distribution of proliferated VSMCs within the scaffold and cellular adherence on the surface of the scaffold showed better results in the static seeding condition than in the dynamic condition. Under the same condition of seeding method as the static condition, the dynamic culture condition showed enhanced proliferation rates of the VSMCs when compared to the static culture condition. In conclusion, to improve the VSMCs proliferation in vitro, static seeding is better than the dynamic condition. In the culture condition, however, culture under the dynamic status is better than the static condition. This was a pilot study to manufacture artificial vascular vessel by tissue engineering.

• 디지털융복합연구
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• 제17권2호
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• pp.47-57
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• 2019

본 연구는 기업조직의 학습문화가 동적역량에 어떻게 영향을 미치며 동적역량이 기업의 학습문화와 기업성과 간의 관계에서 매개효과가 있는지 분석하고, 그 연구결과를 기업실무에 적용할 수 있는지 검증해보고자 하였다. 첫째, 기업조직의 구조가 유기적일수록 재배치역량과 학습역량이 높아지는 것으로 나타났다. 유기적인 기업조직을 가진 집단은 공식적인 처리방식이나 프로세스에 집착하지 않는 관행이 있기 때문에 외부변화에 능동적으로 대응할 수 있는 능력이 존재함을 알 수 있었다. 둘째, 기업조직의 학습문화는 동적역량 중에서 재배치역량에 유의한 정(+)의 영향이 있음을 확인할 수 있었는데 개인수준과 집단수준의 학습문화가 구축되어 있는 기업조직일수록 특히 집단수준의 학습문화가 구축되어 있는 조직일수록 재배치역량이 높아짐을 볼 수 있었다. 셋째, 동적역량의 두 가지 하위요소는 모두 기업성과에 유의한 영향을 미치는 것으로 나타났다. 동적역량이 기업성과에 미치는 직접적인 효과는 확인하였으나 학습문화와 관련된 동적역량의 매개효과는 없는 것으로 나타났다.

• Advances in Computational Design
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• 제4권3호
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• pp.307-326
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• 2019

A low computational cost semi-analytical method is developed, based on eigenfunction expansion, to study the vibration of rectangular plates subjected to a series of moving sprung masses, representing a bridge deck under multiple vehicle or train moving loads. The dynamic effects of the suspension system are taken into account by using flexible connections between the moving masses and the base structure. The accuracy of the proposed method in predicting the dynamic response of a rectangular plate subjected to a series of moving sprung masses is demonstrated compared to the conventional rigid moving mass models. It is shown that the proposed method can considerably improve the computational efficiency of the conventional methods by eliminating a large number of time-varying components in the coupled Ordinary Differential Equations (ODEs) matrices. The dynamic behaviour of the system is then investigated by performing a comprehensive parametric study on the Dynamic Amplification Factor (DAF) of the moving loads using different design parameters. The results indicate that ignoring the flexibility of the suspension system in both moving force and moving mass models may lead to substantially underestimated DAF predictions and therefore unsafe design solutions. This highlights the significance of taking into account the stiffness of the suspension system for accurate estimation of the plate maximum dynamic response in practical applications.

• 대한인간공학회지
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• 제33권4호
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• pp.267-279
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• 2014

Objective: The objective of this study was to define the Dynamic Sitting (DS) through trend analysis and research on the Dynamic Chair (DC) and applied technologies. Background: The effects of changing posture on the human body have been studied to find out healthy sitting postures. It is believed that changing posture is effective in reducing disc pressure on spinal cord and preventing back pain and musculoskeletal disease. But, the definition of DS and trends of DC have not been researched yet. Therefore, trend analysis of DC and its applied technologies are required to define dynamic sitting posture. Method: We researched the type of occupant postures from previous studies. And then, sitting behaviors were classified into three types; (1) sitting and standing, (2) working and studying, (3) taking a rest. Results: Variety shapes of DC and applied technologies were found out. From the result, the trend of DC and applied technology were summarized from three perspectives. ; (1) changing the chair functions according to user's intention, (2) conversion of dynamic chair technologies to office chair mechanism, (3) enables the user to change their sitting posture without operating control device. Conclusion: From this study, we defined dynamic sitting posture and analyzed the trend of DC and its applied technologies. This result might be used to develop an office chair for healthy sitting. But further investigation is required to figure out the technologies and functions for development of healthy chair. Application: The results of the publishing trend analysis might help to determine design concept of office chair.

• 한국해양공학회지
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• 제27권6호
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• pp.7-15
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• 2013

Eco-friendly and sustainable seaweed biomass energy have been under the spotlight as the future of renewable energy. However, seaweed culture is primarily conducted inshore, with the research on offshore culture still in an early stage. For massive biomass production, a systematic engineering approach is required to devise offshore seaweed culture facilities rather than the conventional empirical ones. To establish the fundamental behavior of seaweed culture facilities, the dynamic characteristics of a seaweed culture facility were analyzed in the study. For this purpose, numerical analyses of the seaweed culture facility (a frame type) were carried out by using the hydrodynamic simulation program ANSYS-AQWA. For the analysis, environmental loads were considered using the wave spectra and co-linear current; mooring variables were selected as parameters; and time domain analyses were carried out to acquire the time series responses and eventually the dynamic characteristics. Finally, the mooring performance was evaluated. It was found that the motion could be controlled by adjusting the buoyancy and mooring slope.

• Clinical and Experimental Reproductive Medicine
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• 제43권3호
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• pp.146-151
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• 2016

Objective: This study was conducted to compare the effects of static culture, dynamic culture, and the combination of dynamic culture with specialized surfaces involving co-culture on human embryonic development. Embryos cultured using conventional static culture (SC) techniques served as a control group. We compared dynamic culture using micro-vibration culture (MVC) and micro-vibration with co-culture (MCoC), in which autologous cumulus cells were used as a specialized surface. Methods: We conducted a chart review of patients who were treated between January 2011 and November 2014 in order to compare embryonic development rates and pregnancy rates among the groups. Zygotes were cultured in micro-droplets, and embryos were subsequently selected for transfer. Some surplus embryos were cryopreserved, and the others were cultured for blastocyst development. A micro-vibrator was set at the frequency of 42 Hz for duration of 5 seconds per 60 minutes to facilitate embryo development. Results: No significant differences among the groups were present in patient's characteristics. However, the clinical pregnancy rates were significantly higher in the MVC group and the MCoC group than in the SC group. No significant differences were found in the blastocyst development rate between the SC group and the MVC group, but the blastocyst development rate in the MCoC group was significantly higher than in the SC and MVC groups. Conclusion: The clinical pregnancy rate was significantly increased by the application of micro-vibration to the embryonic cultures of poor responders. The blastocyst development rate was significantly increased by the application of MCoC to surplus embryos.

• Composites Research
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• 제32권5호
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• pp.211-215
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• 2019

정적인 상태인 체외 환경(in vitro)에서의 세포배양 과정은 실제 생체 내 환경에서의 세포발달과정과는 많은 차이가 존재한다. 따라서, 체내 환경의 정밀한 모사를 위해서는, 기계적인 자극을 세포에 전달하여 줄 수 있는 동적 세포배양장치가 필수적이다. 하지만 기존의 동적 세포배양장치에는 튜브, 펌프, 모터 등의 비교적 복잡한 장치들을 필요로 하였으며, 전달되는 기계적 자극도 단순한 형태였다. 본 연구에서는 단순한 장치로 구동되는 동적 세포배양장치를 위하여 전기활성고분자(EAP) 구동기를 동력원으로 하는 소형 동적 세포배양장치를 설계하였다. 이 장치는 다양한 기계적 자극을 세포에 전달하는 것이 가능하다.

• International Journal of Advanced Culture Technology
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• 제5권2호
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• pp.63-73
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• 2017

In this paper, we propose algorithm for determining the static and dynamic posture using the acceleration sensor of smartphone. The measured acceleration values are then analyzed according to a preprocessing to the respective axis (X, Y, Z) and posture (standing, sitting, lying) presents static posture determination criterion. The proposed static posture determination condition is used for static posture determination and dynamic posture determination. The dynamic posture is determined by using regression linear equations. In addition, transition state can be grasped by SVM change in dynamic posture determination. Experimental results are presented using data and app. Experiments were performed using data collected from 10 adults.

• 정보관리학회지
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• 제27권2호
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• pp.217-224
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• 2010

문화와 문화자원에 대한 물음을 전제로 문화자원에 대한 고고학적, 역사적 해석을 시도하였다. 인간의 개별적 행위를 통한 생산과 재생산의 개념으로 문화를 인식하였으며 그 과정과 실천으로 문화역동성 (cultural dynamic)을 표출하였다. 이 논문은 문화자원을 디지털 아카이빙하기 위해서는 문화자원과 함께 그 자원의 생산과정과 의미맥락이 동시에 표현되어야 함을 주장하고 있다. 궁극에 문화자원에 대한 추론과정에서 문화자원은 자원과 관련한 모든 관계자원이 동시에 보존되고 이것의 의미맥락이 살아 있어야 하며 전시, 체험을 비롯한 실제적 활용이 전제되어야 함을 밝히고 있다.

• International Journal of Advanced Culture Technology
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• 제7권3호
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• pp.52-57
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• 2019

This study is about the creation of a character art using the free association. Character in proposed artwork induces the viewer's unconscious experience associated with it and creates new meanings to invigorate the character. When a character that performs both a linguistic function and a visual image function goes through a free association process, the viewer can induce interest and convey the meaning of the character more effectively. We proposed two ways to express the dynamic movement of the character more actively. One is drawing using various colors and free lines, and the other is the movement of the character synchronized with the gesture of the viewer. As a result of implementing dynamic character art, we can see that the viewer was actively involved in the free association process and immersed in the artwork. The viewers participated in the creation of the artwork, changing the shape of the character according to their various gestures.