The objective of this study was to investigate design factors of the electrolysis reactor through the CFD(computational fluid dynamics) simulation technique. Analyses of velocity vector, streamline, chloride ion concentration distribution showed differences in flow characteristics between the plate type electrode and the porous plate type electrode. In case of the porous plate type electrode, chlorine gas bubbles generated from the anode made upward density flow with relatively constant velocity vectors. Electrolysis effect was more expected with the porous plate type electrode from the distribution of chloride ion concentration. The upper part of the electrolysis reactor with the porous plate type electrode had comparatively low chloride concentration because chloride was converted to the chlorine gas formation. Decreasing the size and increasing total area of rectifying holes in the upper part of cathodes, and widening the area of the rectifying holes in the lower part of cathodes could improve the circulation flow and the efficiency of electrolysis reactor.

Middle size of membrane retractable roof is under 25m span which consists of various moving systems. Trolley is the system that leads the membrane to parking place, transferring the load from the membrane to structural cable. When membrane closes roof completely, thus, structural behavior of trolley, which may contain various material with different friction coefficients, should be investigated by vertical load. Nummerical simulation of trolley prototypes, in this research, was performed by incrementation of vertical load. Consequently, this paper studied proper friction characteristics and provided the effective inner materials of trolley.

Building hardware joints are welded in most cases, which have risks of fire and explosion. Besides, the secondary damage of the destruction of the welded parts can be caused by the horizontal displacement of the structure due to earthquake or wind load. This paper compared the horizontal displacement following abilities of welded building hardware and non-welded building hardware. To do this, We conducted actual formation shake table test, and checked on the horizontal displacement following ability of structure by comparing their responses to earthquake load. We made the 2m-high framework to examine the responses of the actually constructed building hardwares, and analyzed the displacement responses of the welded-typed, non-welded-typed, and cruciform bracket building hardwares. We conducted the test by increasing acceleration rate until displacement reached 40mm corresponding to allowable relative story displacement II. The result of the test showed that the building hardware using welding work made cracking and breakage on welded connections of welded building hardware, but non-welded building hardware with no use of welding work and cruciform bracket building hardware make no problem, and that non-welded building hardware is superior to that of the welded building hardware in the horizontal displacement following ability due to earthquake or wind load.

Membrane structure is a system that is stabilized by maintaining a tensile state of the membrane material that originally cannot resist the bending or pressure. Also, it is a system that allows the whole membrane structure to bear external loads caused by wind or precipitation such as snow, rain and etc. Tension relaxation phenomenon can transpire to the tension that is introduced to the fabric over time, due to the innate characteristics of the membrane material. Thus, it is important to accurately understand the size of the membrane tension after the completion of the structures, for maintenance and management purposes. The authors have proposed the principle of theoretically and indirectly measuring the tension by vibrating the membrane surface with sound waves exposures against the surface, which is compartmentalized by a rectangular boundary, and by measuring the natural frequency of the membrane surface that selectively resonates. The authors of this paper measured the tension of preexisting membrane structure for its maintenance by using the developed portable measurement equipment. Through analyzing the measurement data, the authors review the points that should be improved and the technical method for the new maintenance system of membrane tension.

Cap decks used in slim floor system for reducing floor height act as molds for forming floor slabs in structures with a span of up to 6m without temporary supports. When deep decks are employed in a structure with a span of more than 6m, the problem of defection occurs. This study suggests placing tendons at the ends of cap decks in order to create cambers and control defection when preload is applied. Uniformly distributed load was applied by an UTM to the two L/4 points of specimens to observe the deflection of preloaded cap decks. For the test, three 7.5m specimens were fabricated. One of them was a plain cap deck specimen and the others were those with tendons (PC strands or steel bars.

In this study, an acceleration sensor that has optical fibers to measure the inclination and acceleration of a structure through contradictory changes in two-component FBG sensors was examined. The proposed method was to ensure precise measurement through the unification of the deformation rate sensor and the angular displacement sensor. A high sensitivity three-axis accelerometer was designed and prepared using this method. To verify the accuracy of the accelerometer, the change in wavelength according to temperature and tension was tested. Then, the change in wavelength of the prepared accelerometer according to the sensor angle, and that of the sensor according to the change in ambient temperature were measured. According to the test results on the FBG-based vibration sensor that was developed using a high-speed vibrator, the range in measurement was 0.7 g or more, wavelength sensitivity, 2150 pm/g or more, and the change in wavelength change, 9.5 pm/℃.

Solar power is being spotlighted recently as a new energy source due to environmental problems and applications of solar power to curved structures are increasing. Solar panels installed on curved surfaces have different efficiencies depending on its position and the efficient positioning of solar panels plays a critical role in the design of solar power generation systems. In this study, the changing characteristics of solar irradiance were analyzed for hemispherical dome with a large curvature and the positioning of solar panels that can efficiently utilize solar energy was investigated. With an icosahedron-based hemispherical dome consisting of triangular elements as target model, a program for calculating solar irradiance using a normal vector of the solar module on each face was developed. Furthermore, the change of solar irradiance according to the sun’s path was analyzed by time and season, and its effects on shades were also examined. From the analysis results, the effective positioning could be determined on the basis of the efficiency of the solar panels installed on the dome surfaces on solar irradiance.

A single-layerd steel lattice roof, which has 50m span, was constructed. In order to figure out the realistic buckling load level, the structural analysis of this roof structure was performed especially by local snow load. Due to the characteristics of application of snow load, the load combinations of snow should be considered not only global area but also local part so that the critical buckling load could be observed as easy as possible. Geometrical imperfection was simulated to consider inaccurate shape of structure. And then nonlinear analysis were performed. Finally, this paper could investigate that the local snow load with geometrical imperfection decreased the level of buckling load significantly.

This paper aimed at modeling a fine triangular grid for network dome by using Harmony Search (HS) algorithm. For this purpose, an optimization process to find a fine regular triangular mesh on the curved surface was proposed and the analysis program was developed. An objective function was consist of areas and edge's length of each triangular and its standard deviations, and design variables were subject to the upper and lower boundary which was calculated on the nodal connectivity. Triangular network dome model, which was initially consist of randomly irregular triangular mesh, was selected for the target example and the numerical result was analyzed in accordance with the HS parameters. From the analysis results of adopted model, the fitness function has been converged and the optimized triangular grid could be obtained from the initially distorted network dome example.

In this study, a shape design and an analysis considering structural stability were investigated to develop an icosahedron-based hemispherical modular dome. To design this modular dome, a program that can perform icosahedron shape modeling, modularization of joint connection members, and the analysis of structural stability was developed. Furthermore, based on the adopted numerical model, the eigen buckling mode, unstable behavior characteristics according to load vector, and the critical buckling load of the modular dome under uniformly distributed load and concentrated load were analyzed, and the resistance capacities of the structure according to different load vectors were compared. The analysis results for the modular dome suggest that the developed program can perform joint modeling for shape design as well as modular member design, and adequately expressed the nonlinear behaviors of structured according to load conditions. The critical buckling load results also correctly reflected the characteristics of the load conditions. The uniformly distributed load was more advantageous to the structural stability than concentrated load.

Recent increases in the use of Deep Deck, and the study was carried out much of the Deep Deck in the country. Research is the most studies on the behavior of the composite slab after the concrete is cured. However, the large stress is generated in the work load(150kgf/m2) at the time of pouring concrete. The Deep Deck does not satisfy the provisions of deflection during construction when applied to more than 6.0m span. In this study, installed a strand or reinforcing bar at the bottom of the Deep Deck. The pressing force of tension on the strand and rebar was carried out an experiment to produce an upward deflection of the Deep Deck. The loading experiment was carried out and the pressing force the UTM load.

These days, the Composite Slabs with Deep deck plate was commonly used in domestic construction site, and, the application of the Slim Floor system was increased from the Enlargement and High-rise Building. But, Slim Floor system using the deep deck was shown safety problem caused by the deflection and local buckling in construction phase when used to more than 6m. Therefore, for solving the problem, the installation of the shores is essential. This study is realize the long span slab without shores from control the deflection through applied the pre-tensioning elements in cap deck. In addition, by applying the pre-tensioning member as the tensile member of the Cap Deck composite slab, the pre-tensioning member for the shores tries to be used as the structural member. Accordingly, to determine the flexural performance of the Cap deck composite slab through the pre-tensioning force in tensile member, and, the composite effect of the cap deck composite slab by the experiments.

This paper investigates the characteristics of unstable behaviour and critical buckling load by joint rigidity of framed large spatial structures which are sensitive to initial conditions. To distinguish the stable from the unstable, a singular point on equilibrium path and a critical buckling level are computed by the eigenvalues and determinants of the tangential stiffness matrix. For the case study, a two-free node example and a folded plate typed long span example with 325 nodes are adopted, and these adopted examples' nonlinear analysis and unstable characteristics are analyzed. The numerical results in the case of the two-free node example indicate that as the influence of snap-through is bigger; that of bifurcation buckling is lower than that of the joint rigidity as the influence of snap-through is lower. Besides, when the rigidity decreases, the critical buckling load ratio increases. These results are similar to those of the folded-typed long span example. When the buckling load ratio is 0.6 or less, the rigidity greatly increases.

Recent experimental researches supports the hypothesis that mechanical stimuli play a role in regulating specialized molecules expression in articular cartilage in vitro and in vivo. Therefore we are studying bioreactor to provide a stimulus of mimicked real knee environment. Our bioreactor system consists of a joint motion stimulation device and culture chamber. We fabricated a stimulation system similar to movement of the CPM(Continuous Passive Motion) device for human joint motion. This system is composed of a linear stage, ball spline and links. Also we fabricated a culture system for media and circulation and mimicked knee environment. However, Previous culture system has some problems that media leakage and interference of joint model. In this study, we improved a new-chamber system for non-interference of joint model and medium sealing. Then, this system could be used to investigate the effect of dynamic culture.

Mechanical stimulation has been reported to improve cell growth in bone and cartilage regeneration. Various research groups have described their own bioreactors that stimulate cell-seeded scaffolds. We have developed a bioreactor capable of applying controlled compressive loading to a cell-encapsulated agarose hydrogel. To compare the effect of mechanical stimulation on agarose hydrogel, we used one control group (static mode) and five experimental groups. The results show that the intermittent_3sec conditions improve proliferation of cells better than the other conditions studied.

본 연구는 지방 소도시지역 활성화를 위해 그 지역이 본원적으로 소유하고 있는 역사문화자원을 활용하여 지역주민의 삶의 질 향상을 도모하고 관광객의 유입을 유도하기 위한 지역재생사업의 방향설정 및 추진체계를 주 내용적 범위로 한 바, 첫째, 문화재형 지역재생사업에 있어 중요한 것은 문화유산에 중점을 두기보다도 문화재와 관련되어 있는 지역의 인적 요소의 참여가 성공의 중요한 요소로 주목할 필요가 있다. 둘째, 일차적으로 가시적인 성과를 얻기 위한 공공디자인의 도입 효과는 일시적이고 단기적인 성과에 그치기 쉽기 때문에 이와 동시에 지역재생을 수행할 수 있는 지역의 인적 전문가의 육성이 절대적으로 필요하며 동시에 정보를 소통할 수 있는 체계의 구축이 필요하다. 셋째, 타 정부기관의 초창기 지역재생은 물량투입을 주로 하면서도 그 성과는 아직 불투명하지만, 최근의 지역재생의 흐름은 인적 자원을 중시한 방향으로 전환하고 있음을 고려할 필요가 있다. 넷째, 기 시행되었던 문화재청의 “문화재 생생 활용사업”은 소정의 성과를 거두고 있으며 내용상 지역재생으로 발전시킬 수 있는 요소가 상당히 있어 이와 연계 또는 발전시키는 방법도 또 다른 지역재생 시범사업이 될 수 있다. 다섯째, 문화재형 지역재생사업의 특성을 잘 나타내는 사업명을 발굴할 필요가 있다. 여섯째, 지역재생은 장기적인 비전을 가지고 수행해야할 사업이지만, 풍경유산을 중점에 둔 지역재생을 실시할 경우에는 우선 풍경유산의 요소와 체계를 구축하고 관리할 수 있는 체계의 구축이 최우선 과제이다. 일곱째, 문화재청에서는 문화유산의 지역재생을 확충하기 위해서는 이를 전담하는 문화유산 재생전담팀의 설치가 필요하고 이를 통해 체계적이고 효율적인 지역재생의 행정적 접근방법이 필요하다. 동시에 문화유산을 지역재생에 적극적으로 활용할 수 있도록 수평적 연계를 강화하는 것은 필수적이다. 여덟째, 지역재생에서 사회적 자본의 성격을 띤 문화유산은 관리체계가 문화재청과 자치단체로 나누어져 있어 관리체계가 이원화 되어 있지만, 지역재생에서는 이 두 가지를 동시에 활용해야 할 경우도 발생하기 때문에 문화재의 통합관리체계를 구축하여야 한다.

파랑 중 선박의 직진성능을 시뮬레이션을 통하여 비교 검토하였다. 시뮬레이션을 구성하기위해 선박의 3자유도 조종운동방정식을 사용했으며, 선박에 가해지는 파랑강제력은 3차원 특이점 분포법을 사용하여 계산하였다. 시뮬레이션의 외란으로서 규칙파와 불규칙파를 사용하였고 최대사용타각과 제어시간지연을 제어기의 제한조건으로 설정하였다. 조종성능에 따른 직진성능을 검토하기 위해 유체력 미계수를 인위적으로 변화시킴으로서 조종성능이 다른 선박의 시뮬레이션을 구성하였다. Autopilot제어기를 사용한 일정시간의 선박의 직진 시뮬레이션을 수행하고 해당시간동안의 직진거리를 비교하여 선박의 직진성능을 검토하였다.