This study investigated a bio-tensegrity structural system that combines the characteristics of a general tensegrity structural system with a biological system. The final research objective is to accomplish a changeability for the structural system as like the movement of the natural bio-system. In the study, we present a shape finding procedure for the two stage bio-tensegrity system model inspired by the movement pattern of animal backbone. The proposed system is allowing a dynamic movement by introducing the concept of “saddle” for the variable bio-tensegrity structure. Several shape finding analysis example and results are presented and shows a efficient validation and suitability.

Recently, damage to domestic facilities due to strong winds and typhoons is increasing. This study focused on sign structures among various vulnerable facilities. The evaluation of wind fragility was performed considering the destruction of the anchor for fixing, which is one of the failure modes of the sign structures. The performance evaluation of the anchor for fixing was carried out to derive the wind fragility. Three parameters were set and twelve anchor types were selected to perform the pull-out and shear tests. The resistance performance was estimated based on the experimental results. Wind loads were estimated using the Monte Carlo simulation method. Based on this, we derive the wind fragility according to the wind exposure category. Finally, the change of the wind exposure category and the evaluation of the wind fragility according to the experimental parameter were performed.

전자 주게-전자 받게 (D-A) 구조를 가지는 퀴녹살린 유도체들을 산 촉매하 탈수 반응과 Suzuki coupling 반응을 이용하여 합성하였다. 퀴녹살린을 중심으로 dimethylaminobenzene (DMAB)과 triphenylamine이 수평방향과 수직방향에 각각 위치한 QxN2TPA, 그리고 동일한 구조에 DMAB와 methoxy substituted triphenylamine이 조합된 QxN2TPAOME를 합성하였다. UV-visible 분광법 및 순환 전압 전류법을 이용하여, 합성된 유기 단분자들의 광학 및 전기화학적 특성 분석을 실시하였다. QxN2TPA, QxN2TPAOME의 최대 흡수 파장은 THF 용액에서 각각 308, 313 nm를 나타내었으며, HOMO 및 LUMO 에너지 준위는 각각 QxN2TPA(-5.12, -2.98 eV), QxN2TPAOME(-5.01, -2.98 eV)를 나타내었다. 또한, 합성된 퀴녹살린 유도체들을 다양한 용매에 대하여 우수한 용매 의존 발색 효과를 나타내었는데, 이는 분자 내 전하 전달 과정을 통하여 생성된 큰 극성을 지니는 여기상태의 분자 에너지가 용매의 극성이 증가할수록 안정화되는 전자 주게 및 전자 받게 구조를 갖는 공액 물질의 특성에 기인한다.

In this study, the fragility for transmission tower subjected to wind disaster, which has the greatest influence on transmission tower, was developed for 154kV transmission tower located between Yangyang and Sokcho city. The resistance capacity and the limit state required for the evaluation of the fragility were divided into the major part and the auxiliary part in the steel tower. Moreover, the failure of tower was defined as the yielding stress of each member in the tower which could be used to determine their resistance performance. Domestic wind design guideline and criteria for transmission tower was used to determine the wind loads demand on the tower. By comparing the loading demand and resistance capacity, the failure of tower could be determined which in turn used to derive the wind fragility. The results obtained in this study could be used as a reference for damage prediction system of transmission tower and similar structures.

Hair style allows consumers to express their aesthetic sense and individual beauty. However, due to the attributes of hairdressing services and the high expectations of consumers, complaints are increasing rapidly. This study examined the complaint behavior, compensation and hair salon patronage of consumers. Then, a model is presented that explains the complaint behavior for hairstyling, forms of compensation, and hair salon patronage through empirical analysis. This study was conducted by a survey method. A total of 399 questionnaires were used for the analysis. The data were analyzed using SPSS 23.0 and AMOS 23.0 statistical software. The dimension of complaint behavior for hair style included verbal complaints, non-verbal complaints in the salon and private complaints outside the salon. The forms of compensation included re-procedure, psychological, and material compensation. Hair salon patronage was one-dimensional. These results were obtained through exploratory and confirmatory factor analysis. Then the conceptual model was empirically analyzed by covariance structure analysis and obtained in final form through model modification. Verbal complaint behavior positively influenced re-procedure compensation. In addition, non-verbal complaint behavior had positive effects on psychological and material compensation. Hair salon patronage was positively affected by re-procedure and psychological compensation. However, private complaint behavior had a negative effect on hair salon patronage. The direct and indirect effects of the paths among variables were verified by analyzing the mediating effects of different forms of compensations. It is possible to establish differentiated marketing strategies with these findings for consumers with complaint behaviors by considering the forms of compensation.

목적: 본 연구는 망막 영상의 혈관 분할을 위한 새로운 심층 인공 학습 시스템을 구축하는데 목적이 있 다. 기존 CNN (Convolutional Neural Network) 아키텍처를 제시하고, CNN 방식을 토대로 성능을 개선한 DirectNet을 고안하는데 있다. 특히, 기존 CNN에 비해 처리 시간을 크게 단축시키는데 있다. 방법: 제안된 DirectNet 아키텍처는 피라미드 형식의 블록(Block)들로 구성되며 각 블록은 컨볼루션레이 어 (Convolution layer) 묶음을 포함한다. 하나의 블록은 학습 결과를 보존(저장)하는 단위이다. 블록들은 순차적으로 하나씩 증가하며 피라미드 형식으로 쌓이게 되고 이를 통해 초기 학습 결과가 소멸되지 않고 최종 분석에 활용될 수 있도록 하였다. DirectNet은 패치(Patch) 추출과 Pooling 과정 없이 이미지를 학습하여 학습 층을 거듭하여도 원본 이미지와 동일하게 유지되는 것이 특징이다. 또한 다양한 커널사이즈를 활용 하되 Depthwise Separable Convolution(DSC)을 활용하여 색을 구성하는 RGB(Red, Green, Blue)픽셀로 부터 혈관 모양을 인식 및 탐지한다. 결과: DirectNet은 최첨단 패치 기반 CNN 접근 방식 (0.9538 vs 0.9327, 0.7851 vs 0.7346, 0.9782 vs 0.9730, 0.8458 vs 0.7987)과 비교하여 더 높은 정확도, 감도, 특이도 및 정밀도 값을 제공하였다. Direct Net의 학습 시간은 8시간에서 1시간, 테스트에 소요된 시간은 1시간에서 이미지 당 6초로 크게 단축하였다. 결론: 제안 된 심층 학습 아키텍처는 기존의 CNN 방식으로 진행한 학습 시간에 비해 8배, 테스트에서 600배 빠른 속도로 결과를 제공한다. DirectNet은 CNN에 비해 2.11%의 약간 높은 정확도를 보였으며, 다 른 측정 항목에서도 동등하거나 그 이상의 결과를 보여 분석 시간 효율을 크게 높였다.

Lithium-ion batteries have been considered the most important devices to power mobile or small-sized devices due to their high energy density. LixCoO2 has been studied as a cathode material for the Li-ion battery. However, the limitation of its capacity impedes the development of high capacity cathode materials with Ni, Mn, etc. in them. The substitution of Mn and Ni for Co leads to the formation of solid solution phase LiNixMnyCo1-x-yO2 (NMC, both x and y < 1), which shows better battery performance than unsubstituted LiCoO2. However, despite a high discharge capacity in the Ni-rich compound (Ni > 0.8 in the metal site), poor cycle retention capability still remains to be overcome. In this study, aiming to improve the stability of the physical and chemical bonding, we investigate the stabilization effect of Ca in the Ni-rich layered compound Li(Ni0.83Co0.12Mn0.05)O2, and then Ca is added to the modified secondary particles to lower the degree of cationic mixing of the final particles. For the optimization of the final grains added with Ca, the Ca content (x = 0, 2.5, 5.0, 10.0 at.%) versus Li is analyzed.

Current petrochemical product mainly comes from light olefin, such as ethylene and propylene. these olefins can be obtained as mixture form of olefin/paraffin, which is co-product of naphtha cracking process. However, the mixture of light olefin and paraffin is considerably difficult to separate because they have similar physicochemical properties such as density, boiling point, and molecular weight. Cryogenic distillation is currently utilized, but still suffered from high operating cost. Membrane separation with polyimide-based material is a promising alternative due to its lower energy cost and modular operation. Here, we synthesized composite membrane with metal-organic framework (MOF) based on polyimide exhibiting high permeability and selectivity in propylene/propane separation, as well as simple preparation and high stability.

We synthesized the poly(4-vinylbenzyltributylammonium hexanesulfonate) P[VBTBA][HS] which was obtained via anion exchange with hexanesulfonate after acquiring monomer [VBTBA][Cl] by Menshutkin reaction to investigate its feasibility as draw solute for forward osmosis process. P[VBTBA][HS] shows lower critical solution temperature (LCST) property at about 21℃, while LCST property of [VBTBA][Cl] and P[VBTBA][Cl] was not confirmed. This result suggests that P[VBTBA][HS] can be recovered from solution by heating them to above LCST. In AL-FS mode with solution of 20 wt% P[VBTBA][HS] at 15℃, water flux and reverse solute flux were found to be about 6.43 LMH and 0.59 gMH. This study can provide an understanding of new way of proceeding draw solute and information for the potential design and synthesis of thermo-responsive organic material.

Laminated graphene oxide (GO) membrane has great attention for ultrafast flux membrane with well-defined pore structure. However, laminated structure is sensitive to various factors such as functionalization, fabrication method and especially support morphology due to ultrathin thickness. Herein, we investigated surface roughness effect by controlling systematically wrinkled structure of support with ion beam treatment. Wrinkled surface of support generates free volume at interface, facilitating fast water transport, which confirmed 6.4 times enhancement on permeation of water while maintaining high rejection of all dye molecules. The tunability of nanostructure through support control can provide development for ultrathin GO membrane in water purification.

Perfluorinated sulfonic acid (PFSA) ionomers have been widely used as representative polymer electrolyte membrane (PEM) materials for water electrolysis to generate hydrogen and oxygen gases with a high purity (e.g., 99.999%) simultaneously. PEM should satisfy high selectivity of proton to water and act as gas barrier to hydrogen and oxygen in order to improve current efficiency which is a barometer to determine how effectively the electric energy is used for water electrolysis. In this study, PFSA ionomers with different chemical architectures and equivalent weights were used to make PEM materials for water electrolysis. The structure-property-performance relationship was systematically investigated.