• Wind and Structures
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• 제27권3호
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• pp.163-173
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• 2018

The design wind pressure for low-rise buildings in the ASCE 7-10 is defined by procedures that are categorized into the Main Wind Force-Resisting System (MWFRS) and the Components and Cladding (C&C). Some of these procedures were originally developed based on steel portal frames of industrial buildings, while the residential structures are a completely different structural system, most of which are designed as low-rise light-frame wood constructions. The purpose of this study is to discuss the rationality (or irrationality) of the extension of the wind loads calculated by the ASCE 7-10 to the light-frame wood residential buildings that represent the most vulnerable structures under extreme wind conditions. To serve this purpose, the same approach as used in the development of Chapter 28 of the ASCE 7-10 that envelops peak responses is adopted in the present study. Database-assisted design (DAD) methodology is used by applying the dynamic wind loads from Louisiana State University (LSU) database on a typical residential building model to assess the applicability of the standard by comparing the induced responses. Rather than the postulated critical member demands on the industrial building such as the bending moments at the knee, the maximum values at the critical points for wood frame buildings under wind loads are used as indicators for the comparison. Then, the critical members are identified through these indicators in terms of the displacement or the uplift force at connections and roof envelope. As a result, some situations for each of the ASCE 7 procedures yielding unconservative wind loads on the typical low-rise residential building are identified.

• 한국기계가공학회지
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• 제17권3호
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• pp.127-133
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• 2018

To reduce fuel consumption, research on the weight reduction of vehicles is being actively carried out. Researchers have typically tried to replace metal materials with composites materials, but these materials did not satisfy the required strength and rigidity of a vehicle. Composites are usually not used because of their high cost. There are incomplete studies on lightweight trucks that transport cargo. Therefore, in this paper, we enhance the lightness and mechanical strength through design optimization of the deck frame for a lightweight truck. For that purpose, the side member and cross member, which are mounted on the lower part of the truck to assure the safety of the vehicle and support the luggage load, were targeted. The result of numerical analysis on the safety of the frame was obtained by changing the shape of each cross-section. To verify the numerical analysis, we compared it with the theoretical value of a cantilever beam. As a result, the suitability of the cross-sectional shapes of each frame was confirmed through numerical analysis.

• ETRI Journal
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• 제29권4호
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• pp.411-420
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• 2007

The steady evolution of mapping technology is leading to an increasing availability of multi-sensory geo-spatial datasets, such as data acquired by single-head frame cameras, multi-head frame cameras, line cameras, and light detection and ranging systems, at a reasonable cost. The complementary nature of the data collected by these systems makes their integration to obtain a complete description of the object space. However, such integration is only possible after accurate co-registration of the collected data to a common reference frame. The registration can be carried out reliably through a triangulation procedure which considers the characteristics of the involved data. This paper introduces algorithms for a multi-primitive and multi-sensory triangulation environment, which is geared towards taking advantage of the complementary characteristics of spatial data available from the above mentioned sensors. The triangulation procedure ensures the alignment of involved data to a common reference frame. The devised methodologies are tested and proven efficient through experiments using real multi-sensory data.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.844-847
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• 2003

Display devices are becoming increasingly important as an interface between humans and machines in the growing information society. In display devices, PDP (Plasma Display Panel) has many advantages in that it has wide screen, wide viewing angle and is light weight, thin. In PDP driving method, if the brightness of input image is high, applying the fixed sustain pulse to the PDP panel will raise the PDP power consumption and may damages the PDP panel. To overcome these problems, the Plasma AI driving method was introduced by the Matshushita co. in Japan. The Plasma AI driving module calculates the peak value and average value of 1 frame image and adjusts the gradation and sustain pulses for 1 frame sustain. In this paper, the proposed PDP driving module is based on the Plasma AI driving module. The proposed driving module calculates peak value and average value, and the brightness distribution of 1 frame image. Using brightness distribution, the proposed driving module divides 1 frame input image into 15 image patterns. For each image pattern, minimum sustain pulses and sub-frames are used for the brightness of 1 frame image and the sustain weight for 64, 128, 192 gradation is proposed. Therefore, the sustain power consumption can be reduced.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2002년도 춘계학술대회 논문집
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• pp.446-451
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• 2002

Honeycomb structures have advantages in weight reduction with stiffness increment. As far as noise is concerned, however a light aluminum structure, instead of a steel frame, should have an equivalent mass density in order to maintain sound insulation performance. In this paper, an evaluation of a material effect on noise has been examined.

• ETRI Journal
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• 제30권2호
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• pp.290-300
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• 2008

We apply IEEE 802.3 frame burst mode (FBM) to the Ethernet passive optical network (EPON) downstream link and compare its performance with non-frame burst mode for various traffic patterns. Although in light traffic loads (p<0.5) the efficiency of the FBM mechanism is not significant, it does feature high throughput, small jitter, low queue occupancy, and short queuing delay in optical line terminals under various traffic loads with various numbers of optical network units (ONUs). The FBM performance always approaches that of full-duplex mode, especially under heavy traffic loads (p>0.5). Moreover, an increase in number of ONUs will decrease the burst performance. Our work shows that FBM scheme is very useful for EPON transmission and has low design complexity.

• 한국자동차공학회논문집
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• 제11권3호
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• pp.155-160
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• 2003

For the weight reduction of vehicle body up to 20∼30% compared to the conventional monocoque steel body·.in-white, most automotive manufacturers have attempted to develop the aluminum intensive body-in-white using an aluminum space frame. In this paper, the crush tests and simulations for the aluminum extrusions filled with the structural from are performed to evaluate the collapse characteristics of that light weighted material. From these studies. the effectiveness of structural for is evaluated in improving automotive crashworthiness. In order to improve the improve energy absorption capability of the aluminum space frame body, safety design modifications are performed and analyzed based on the suggested collapse initiator concepts and on the application of the aluminum extrusions filled with structural foam. The effectiveness of these design concepts on the frontal and side impact characteristics of the aluminum intensive vehicle structure is investigated and summarized.

• 한국기계가공학회지
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• 제7권4호
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• pp.44-49
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• 2008

The characteristic of magnesium alloy is the most light in utility metal, the effect of electromagnetic wave interception, excellent specific strength and absorptiveness of vibration. Although magnesium alloy with above characteristic is a subject matter which is suitable in world-wide tendency of electrical component frame, sheet magnesium alloy is difficult to process. Therefore, forming analysis of sheet magnesium alloy and applying warm-working to process are indispensable. Among Finite element method, the static implicit finite element method is applied effectively to analyze sheet magnesium alloy stamping process, which include the forming stage. In this study, it was focused on the crack, wrinkling and spring back on sheet magnesium alloy stamping by the static implicit analysis. According to this study, the result of simulation will give engineers good information to access the forming technique on sheet magnesium alloy. And its application is being increased especially in the production of electrical component frame for the cost reduction, saving of defective ratio, and improvement of Productivity.

• International Journal of Automotive Technology
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• 제4권3호
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• pp.141-147
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• 2003

For improving high-safety, convenience, and ride comfort, the automotive design suffers from radical increase of the weight, the recycling-related rules, regulations on the waste gas, and environmental protection of the resources. Among them, it is well known that the weight increase is the most critical. Thus, in order to minimize the weight of the body-in-white that takes up 20-30% of the whole weight of the automobile, most automotive manufacturers have attempted to develop the aluminum intensive body-in-white using aluminum space frames. In this research, the crush test and simulation for aluminum extrusions are performed to evaluate the collapse characteristics of that light weighted material. Also. the same test and simulation was done for aluminum extrusions filled with structural foam. Then, these results are analyzed and compared. From these studies, the effectiveness of structural foam is evaluated in improving automotive crashworthiness. Finally, the design strategy and guideline of the structural form are suggested in order to improve the crashworthiness for aluminum space frame in the vehicle.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.273-276
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• 2004

Dynamic model of the Korea standardized rubber-tired AGT light rail vehicle, and boundary conditions between vehicle and infrastructures (running track, guidance rail) were defined to analyze vehicular vibration behaviors occurred at the worst condition for straight running track. Using the commercialized software RecurDyn, resultant forces and vibration accelerations of car body and bogies were analyzed. Based on the Korea performance test criteria for urban transit, vertical and lateral vibration of car body were calculated and evaluated as wearing condition of guide wheels. And resultant forces between bogie guidance frame and guide rail in straight running track were analyzed. As the results, the Korea standardized rubber-tired AGT light rail vehicle satisfied the performance criteria and design requirement .