• 대한토목학회논문집
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• 제10권3호
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• pp.87-98
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• 1990

본 연구에서는 Elman둥이 상시하중의 경우에 대해 제안한 새로운 형태의 캔키레바식 옹벽 설계방식을 지진하중을 고려한 경우에까지 확대적용하여 예상되는 효율성을 설계예를 통해 분석하였으며, 좀더 안전한 측에서의 셜계검토를 위해 캔티레바식 옹벽의 자체중량 및 뒷채움 일부분의 모래중량에 의한 수평관성력 등을 포함하는 분석법이 제시되었다. 또한 한계 평형상태가 아닌 다양한 토압상태에서의 설계검토를 목적으로 Mononobe-Okabe 동적토압계산식을 변형하였다. 결론적으로, 기초슬래브의 밑면이 경사진 캔티레바식 옹벽형태가 내진설계에 있어서 가장 효율적임을 알 수 있었다. 즉 다른 형태의 캔티레바식 옹벽에 비해, 활동에 대한 안전율은 가장 크면서도 옹벽축조에 관련된 콘크리트량, 굴착량 및 뒷채움 모래의 양은 가장 절감되는 효과가 있음을 알 수 있었다. 후단부분을 $45^{\circ}$만큼 경사지게하는 캔티레바식 옹벽형태는, 상시하중 및 비교적 낮은 수준의 지진에 대해서는 효율성이 예상되나, 수평진도가 커짐에 따라 이와 같은 효율성을 기대할 수 없음을 알 수 있었다. 이에대한 주된 원인은, 옹벽 후단부분에 작용하는 수평발생토압합력의 감소율이 수평진도가 커짐에 따라 점차적으로 작아지는데 있다. 이외에도 기초슬레브의 밑면이 경사진 캔터레바식 옹벽에 관련된 설계도표를, 뒷채움 및 기초지반모래의 내부마찰각 크기, 지진하중시의 활동에 대한 안전율 규정 등을 각각 달리하여 제시하였다.

• Smart Structures and Systems
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• 제23권1호
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• pp.91-106
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• 2019

Adopting sloped rolling-type isolation devices underneath a raised floor system has been proved as one of the most effective approaches to mitigate seismic responses of the protected equipment installed above. However, pounding against surrounding walls or other obstructions may occur if such a base-isolated raised floor system is subjected to long-period excitation, leading to adverse effects or even more severe damage. In this study, real-time hybrid simulation (RTHS) is adopted to assess the control performance of a smart base-isolated raised floor system as it is an efficient and cost-effective experimental method. It is composed of multiple sloped rolling-type isolation devices, a rigid steel platen, four magnetorheological (MR) dampers, and protected high-tech equipment. One of the MR dampers is physically tested in the laboratory while the remainders are numerically simulated. In order to consider the effect of input excitation characteristics on the isolation performance, the smart base-isolated raised floor system is assumed to be located at the roof of a building and the ground level. Four control algorithms are designed for the MR dampers including passive-on, switching, modified switching, and fuzzy logic control. Six artificial spectrum-compatible input excitations and three slope angles of the isolation devices are considered in the RTHS. Experimental results demonstrate that the incorporation of semi-active control into a base-isolated raised floor system is effective and feasible in practice for high-tech industry.

• 산업기술연구
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• 제19권
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• pp.135-145
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• 1999

This thesis is to investigate the sliding behavior of cantilever retaining wall by using the commercially available program of FLAC to simulate its behavior numerically. Cantilever retaining walls with flat base, sloped base and base with shear key, uniform surcharges being applied on the surface of backfill, were investigated to figure out appropriate location of shear key beneath the base of wall and, thus, its applicability to field condition was assessed by comparing the analyzed results to each other. On the other hand, previously performed centrifuge model test results (Eum, 1996) were analyzed numerically with FLAC to compare test results with respect to characteristics of load-settlement of surcharges and load-lateral movement of wall. Based on the failure mechanism observed during centrifuge tests, limit equilibrium method of finding the ultimate load inducing the sliding failure of wall was used to compare with values of the ultimate load obtained from conventional method of limit equilibrium method. Therefore, appropriate location of shear key was determined to mobilize the maximum resistance against sliding failure of wall.

• Structural Engineering and Mechanics
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• 제64권2호
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• pp.233-241
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• 2017

Earlier numerous studies have been done on implementation of Tuned Liquid Damper (TLD) for structural vibration control by many researchers. As per current review there is no significant study on a sloped bottom TLD. TLD's are passive devices. A TLD is a tank rigidly attached to the structure and filled partially by liquid. When fundamental linear sloshing frequency is tuned to structure's natural frequency large sloshing amplitude is expected. In this study set of experiments are conducted on flat bottom and sloped bottom TLD at beach slope $20^{\circ}$, $30^{\circ}$ and $45^{\circ}$, for different types of structures, mass ratio, and depth ratio to investigate the overall effectiveness of TLD and specific effect of TLD parameters on structural response. This experimental study shows that a properly designed TLD reduces structural response. It is also observed that effectiveness of TLD increases with increase in mass ratio. In this experimental study an effectiveness of sloped bottom TLD with beach slope $30^{\circ}$ is investigated and compared with that of flat bottom TLD in reducing the structural response. It is observed from this study that efficiency of sloped bottom TLD in reducing the response of structure is more as compared to that of flat bottom TLD. It is shown that there is good agreement between numerical simulation of flat bottom and sloped bottom TLD and its experimental results. Also an attempt has been made to investigate the effectiveness of sloped bottom TLD with beach slope $20^{\circ}$ and $45^{\circ}$.

• KIEAE Journal
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• 제9권1호
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• pp.23-30
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• 2009

A lightcourt design is typically used to address issues concerning aesthetics, feeling, and mood. From the view point of environmental aspect, as an ecological shaft space, it plays a key role in controlling inner quality. In particularly, the lightcourt concept allows the exploitation of daylighting by bring natural light into the center of the building, thus eliminating dark deep spaces. Additionally, the lightcourt shades the inner space in summer. The amount of light available at the base of the lightcourt depends on a number of factors; translucency of the top, reflectance and the geometry of the space. In this paper is to exemplify a lightcourt configuration with a sloped wall. It promises the maximized a sense of freedom and daylighting availability. It is a matter of course that the lightcourt with open-top plays a role as a light source for the adjacent space to the lightcourt. A series of lighting simulation provides performance data of daylighting with changing photometric factors. For the case that a skylight is not available, an electric lighting design with metal halide lamps has been established to create luminous ceiling. As expected, a sloped lightcourt with open-top exposes its superiority of daylighting source. Ancillary considerations to enhance of daylighting potential for the adjacent space have been issued with performance data.

• Journal of Plant Biology
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• 제17권3호
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• pp.107-112
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• 1974

Leaf temperature is complicated with the microclimate and the dry matter production in a plant community. But a daily change of leaf temperature varying by the locality in plant body or plant community is not yet clear. To resolve such a question, following experiment was designed; Helianthus tuberosus L., Glycine max L., Zea mays L., Impomoea batatas Lam., and Cucurbita moschata var. toonas Makino were planted in the different sandy loam, $2m{\times}2m-quadrat$, which has a eastern, southern, western and northern edge. In each plot 17-25 plants were planted and the distances between individuals spaced uniformly. And leaf temperature were measured by MR3-C type thermistor from 14th May through 20th August. It is seems that the upper leaf is affected by solar radiation, the lower leaf by released heat from the earth and the middle leaf by the conditions of both zones. Measuring the temperature of a leaf that is on terminal, central, left and right margins and base part, temperature of control plant in a leaf was sloped during about two hours from noon. It is noticeable as a "noon sleeping" phenomenon.henomenon.

• 한국도로학회논문집
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• 제18권1호
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• pp.85-90
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• 2016

PURPOSES : The objective of this paper is to understand the deterioration phenomenon and causes in the pavement of a ramp area. METHODS : Ramp areas need to be sloped because of the centrifugal force, which depends on the vehicle speed and grade of the ramp area. As a result, vertical and horizontal forces are applied on the pavement surface of the ramp area. Furthermore, the horizontal force depends on the vehicle speed and grade of the ramp area. In order to analyze the pavement structure of a ramp area, a multi-layered elastic analysis program was used to evaluate the weakest link of fatigue cracking deterioration, according to the simultaneously applied vertical and horizontal forces. RESULTS : From case studies related to the bonding conditions between the surface and base layer in a ramp area, it was found that the partially bonded cases resulted in a critical potential of fatigue cracking deterioration, in a comparison of 50%, 70%, and fully bonded cases. CONCLUSIONS : According to the results of the case studies, the pavement structure system should be reinforced by upgrading the material or increasing the thickness compared to the general pavement areas, in order to provide a performance life similar to the mainline pavements in the ramp areas.

• 한국문헌정보학회지
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• 제11권
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• pp.3-42
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• 1984

This is to establish a model of the standardization of shelving, chairs, tables and card cabinets for college and university libraries in Korea. The size of furniture was measured on the base of the analysis of the human factors, such as the standard size of human bodies of the college students in Korea, the scope of work area, the moving degree of muscles, the limit of the visual field, etc. The results of this study are as follows: 1. It is desirable that the standard shelf length should be 800mm. and the maximum . shelving height should not exceed 1,803mm. And it is desirable that the bottom shelf has a ground clearance of about $210\~390mm$. 2. It is advisable that the sloped shelving has the slope from about 1,000mm, or 930mm, and the gradient should be $19^{\circ}$ from the above mentioned sloping position and the bottom of each shelf. And it is desirable that the slope height of each shelf should be 77mm. 3. It is advisable that the seat area for users should be $410\~420\times420mm$, and the seat height should be $390\~0400mm$. 4. It is desirable that the table size per user should exceed $490\times880\~890mm$, and the table height should be $680\~690mm$. 5. It is advisable that each tray of the card cabinet should hold about 740 cards, and the depth should exceed 430mm. And it is desirable that the maximum height of card cabinets should be as follows: 60du(drawer units)-$1,400\~1,460mm$, 30du-1, 300mm, 15du-1,100mm. In addition, it is advisable that the 30du cabinet should accomodate 5 trays vertically and 6 trays horizontally for avoiding the worst working position rather than 6 trays vertically and 5 trays horizontally. 6. It is desirable that the height of sliding reference shelves in card cabinets, or consultation tables should be 900mm. But in the case of the sliding shelves, it is desirable to be as follows: 15du-900mm when the card cabinet height is more than 1,100, mm, but unnecessary when less than 1,100mm high, 30du-1,000mm, or 1,100mm in the case of $5\times6du$, but 900mm in the case of $6\times5du$, $60du-900\~950mm$ when the card cabinet height is $1,400\~1,460mm$.

• 한국전통조경학회지
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• 제29권4호
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• pp.111-123
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• 2011

본 연구는 한국, 중국, 일본의 계단식 논의 현황 및 보전관리방안을 중점적으로 살펴보고, 한국 계단식 논이 명승자원으로 보전되고, 지속적으로 연구될 수 있는 기초자료 제시를 목적으로 하며, 본 연구에서 도출한 결과는 다음과 같다. 첫째, 우리 선조들은 경사지를 개간하면서도 경관의 훼손을 최소화 하며 다랑이 논을 축조하는 방법을 전수하였으며, 다랑이 논은 한국 고유의 전통 경관으로 가치를 지니고 있다. 그러나 경작의 운용면에서 불리한 환경에 놓여있어, 휴경(休耕)되거나 폐경(廢耕)되어 사라져가는 다랑이 논의 면적이 증가하고 있는 추세이다. 이러한 문제에 대하여 정부는 소실되어가는 전통 경관인 다랑이 논의 보전을 위해서 '한국 다랑이 논 데이터베이스 구축'을 실시하여 우수 경관자원 발굴의 토대를 마련해야 할 것이다. 문화 경관적 가치가 높다고 판단되는 다랑이 논은 명승지나 기념물로 지정 관리되어 법적 보호를 받을 필요가 있다. 둘째, 한국 계단식 논의 효율적 관리와 지속적인 연구를 위한 국 내외 문헌조사 분석의 결과는 다음과 같다. 관련 법규 부분에서 계단식 논은 문화재보호법에 의해 명승으로 지정 관리되고 있을 뿐, 그 외에 경관법 및 농어촌관련법은 계단식 논 경관계획 수립을 위한 참고사항으로 법적 구속력 및 실효성이 없는 상태이다. 이에 계단식 논의 효율적 보전과 관리를 위해서는 계단식 논 관련법의 제정, 제도의 보완과 확립이 반드시 이뤄져야 할 것으로 판단된다. 셋째, 본 연구에서 한국, 중국, 일본 계단식 논의 조사분석 결과가 시사하는 바는 다음과 같다. 계단식 논의 보전을 위한 관련 법규는 조금씩 국가별 차이를 보이고 있으나, 우수한 경관자원의 보전과 보호에 바탕을 두고 지정 관리하고 있다는 점에서 유사하다. 국가별 계단식 논 관련 법규의 조사결과로 일본의 문화재보호법과 경관법의 연동, 중국의 자치지구 법규 등의 제도 도입을 통한 한국 계단식 논 경관의 보전 방안이 보완되어야 할 것이다. 넷째, 한국 계단식 논의 효율적 보전을 위해 주민 자체의 교육을 통한 인식 향상과 함께 계단식 논 관리를 위한 마을 단위 조직을 운영해야 한다. 한국 계단식 논 마을주민들의 자발적 참여를 위한 대책들을 도입할 경우, 각 지역의 마을에서 주민들의 합의나 논의 관리, 주변 환경미화 등의 부분에서 서로 일체감을 유발하여 마을의 활성화가 가능할 것으로 사료된다. 또한 마을단위 주민자치 운영회는 문화재청 관계자, 대학교수 등 전문가 집단의 자문 기구를 두어 운영에 대한 자문 및 지원을 쉽게 받을 수 있는 시스템을 구축해야 하며, 도시 주민과의 교류를 통한 계단식 논 지역의 활성화 또한 중요하다고 사료된다.