• Journal of the Korean Geosynthetics Society
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• v.10 no.2
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• pp.81-89
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• 2011

This paper introduces a recently developed thinning-out timber framed earth retaining wall system. Timber framed retaining walls are usually designed by using design code of gravity type retaining wall but internal stability of timber framed earth retaining walls is often neglected. In this study, it is recommended to use the design code for segmental retaining walls by National Concrete Masonry Association (NCMA, 1997) to check internal stability of timber framed earth retaining wall. Based on the several shear test results for 3 types of timber frames, a simple design chart including internal stability is suggested.

• The Journal of the Korea Contents Association
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• v.11 no.12
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• pp.504-510
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• 2011

In the culture performance field, device technologies for public performances with new concept is on the rise with the advancement of science. Most designers make use of the performance devices to achieve powerful and dramatic effect in their performances. It increases the perfection of performance. Most of all, applying high technology to performances' stage leads to enhance the space efficiency of the limited stage as well as to enable us to run a fully unmanned performance. This paper proposes a reconstructible electric block system for public performances' stage to heighten the fantastic stage effect variously.

• Journal of the Korean Society for Railway
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• v.15 no.5
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• pp.467-475
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• 2012

Static and dynamic train load tests were conducted to evaluate the train load transfer mechanism in the roadbed which was retained by two types (fully and partially) of segmental retaining walls reinforced by geogrid. The test roadbed was 2.6m high, 5m wide, and 6m long. A combination of earth pressure gages, displacement transducers, and strain gages were placed in specific locations to measure the responses. Test results showed that the wall displacement pattern as well as the earth pressure for the fully reinforced retaining wall was different from those for the partially reinforced retaining wall. In the dynamic train load test, the strain in the upper part of the wall tended to decrease, and both the residual deformation and the rate of the deformation were significantly lower than those in the current design standard.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.337-342
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• 2008

최근 들어 기존의 녹색 바탕 차량 번호판에서, 흰색 바탕의 신 차량 번호판으로 교체되고 있다. 하지만 아직 기존 차량 번호판이 신 차량 번호판으로 전면 교체되지 않아 두 번호판 모두 사용되고 있다. 따라서 주차관리 시스템, 속도위반, 신호 위반 등 무인 카메라를 이용한 시스템에서, 기존 차량 번호판과 신 차량 번호판의 특징에 맞는 인식 시스템이 요구된다. 본 논문에서는 이러한 문제를 해결하기 위해 기존 차량 번호판과 신 차량 번호판을 통합한, 지능형 차량 번호판 인식 시스템을 제안한다. 무인 카메라에서 획득된 차량 영상에서 번호판의 색상 정보를 이용하여 기존 차량 번호판과 신 차량 번호판을 구분한다. 기존 차량 번호판인 경우에는 HSI 컬러 공간을 이용하여 이진화를 적용하며, 신 차량 번호판인 경우에는 블록 이진화를 적용한다. 이진화된 영상을 대상으로 차량의 형태학적 특징을 이용하여 잡음을 제거한 후, 차량 번호판 영역을 추출한다. 추출된 차량 번호판 영역에 대해 Labeling 알고리즘을 적용하여 개별 문자를 추출한다. 추출된 개별 문자는 FCM 알고리즘을 적용하여 인식한다. 제안된 차량 번호판 추출 및 인식 방법의 성능을 평가하기 위해 160장의 기존 차량 영상과 100장의 신 차량 영상을 대상으로 실험한 결과, 제안된 차량 번호판 추출 및 인식 방법이 실험을 통해서 효율적인 것을 확인하였다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.1
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• pp.106-114
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• 2006

Uses of geosynthetics as a reinforcing material for earth structures have ever increased due to their excellent economy. fine external appearance. and easy construction. In the current practice of geosynthetics. however, the lacks of the standardized method of evaluating the soil/geosynthetics friction properties and the inconsistency of conventional design methods develop confusion to the civil engineers. The purpose of site monitoring of the retaining wall reinforced by geogrids was to evaluate the applicability of existing design methods to, and performance of. CHAMSTONE wall system. Full scale field performance during and after construction was monitored by incorporating instrumentation including strain gauges on the geogrid and soil pressure cells. The difference of the reinforcing effects of geosynthetics embedded in the soil will be also investigated by comparing of the line and curve types of retaining wall reinforced by geogrids with block type facings.

• Journal of the Korean GEO-environmental Society
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• v.4 no.1
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• pp.11-17
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• 2003

The existing geotextile reinforced soil wall methods have a demerit in terms of esthetic view because concrete panel or block are used as wall facing of the methods. If grass planting walls could be used in reinforced soil slope or wall methods, efficiency of the methods would be increased with maximization of advantage of the methods. In this study, some possible methods in which grass planting wall is used as wall facing are devised. A series of laboratory model tests were performed to investigate the behavior of newly devised methods in order to compare with the results of each others. As a major result, it was found that this kinds of grass wall facing methods could be accepted as a new construction method even in the sense of stability.

• Journal of the Korean Geosynthetics Society
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• v.10 no.2
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• pp.45-53
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• 2011

Recently reinforced retaining walls secure their position as a stabilized method of construction replacing concrete retaining walls gradually. However, in the event of using extensible reinforcement, a bulging phenomenon can be happened in the front of reinforced retaining walls. Bulging of reinforced retaining walls means a phenomenon that, in the height of an arbitrary block, the upper part and the lower part of the block don't secure a relative position in design. Therefore, it is judged that it has the necessity to be examined in design since reinforcement needs metamorphosis to some degree to display tensile force. Therefore, the study examined about how extensibility of reinforcement had an effect on movement of reinforced retaining walls through a small-scale model test with aluminum rods. The study used Changhoji(traditional korean paper made from mulberry bark) as inextensible reinforcement and membrane as extensible reinforcement. As the result of the test, rigidity of reinforcement had a lot of effects on displacement of reinforced retaining walls and generally occurrence point of the maximum horizontal displacement had a tendency transferring to the upper part of walls according to rigidity of reinforcement was increased.

• Journal of KIISE:Computer Systems and Theory
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• v.37 no.5
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• pp.285-291
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• 2010

Flash memory has many good features such as small size, shock-resistance, and low power consumption, but the cost of flash memory is still high to substitute for hard disk entirely. Recently, some mobile devices, such as laptops, attempt to use both flash memory and hard disk together for taking advantages of merits of them. However, existing OSs (Operating Systems) are not optimized to use the heterogeneous storage media. This paper presents a new buffer cache management scheme. First, we allocate buffer cache space according to access patterns of block references and the characteristics of storage media. Second, we prefetch data blocks selectively according to the location of them and access patterns of them. Third, we moves destaged data from buffer cache to hard disk or flash memory considering the access patterns of block references. Trace-driven simulation shows that the proposed schemes enhance the buffer cache hit ratio by up to 29.9% and reduce the total I/O elapsed time by up to 49.5%.

• Smart Media Journal
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• v.11 no.10
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• pp.76-88
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• 2022

Personal information leakage is very harmful as it can lead to additional attacks using leaked information as well as privacy invasion, and it is primarily caused by hacking server databases of institutions that collect and store personal information. We propose a scheme that allows a service-requesting user to authorize a secure delegated transfer of his personal information to the service provider via a reliable authority and enables only the two parties of the service to retrieve the provided information stored on a blockchain ensuring data confidentiality. It thus eliminates the necessity of storing customer information in the service provider's own database. As a result, the service provider can serve customers without requiring membership registration or storing personal information in the database, so that information leakage through the server database can be completely blocked. In addition, the scheme is free from the risk of information leakage and subsequent attacks through smartphones because it does not require a user's smartphone to store any authentication credential or personal information of its owner.

• Journal of the Korean Geotechnical Society
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• v.30 no.4
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• pp.5-19
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• 2014

In this study, the structural analysis is performed on the method of shallow block and deep cement mixing pile, and then their characteristics and associated behaviors were analyzed. In the case of continuous beam analysis, the predicted settlement was very small, and shear force and bending stress are somewhat overestimated. The frame method is similar to numerical analysis in the internal force shallow block and long pile, but because the settlement of pile is underestimated, the additional calculation using the reaction of the long pile is necessary. For soil arching method and piled raft foundation method, the excessive axial force of long pile was predicted because the load sharing of pile is very large compared to the other methods. In the behavior of the shallow block and deep pile method, the settlement of shallow block and contact pressure are much in the center than the edge. In the estimating method considering the interaction between improved material and ground, the load sharing of the soil-cement pile ranges from 20% to 45%, and the stress ratio is 2.0~5.0 less than piled DCM. The maximum member forces at the boundary conditions of pile head are similar, but in fixed head the axial force and vertical displacement are different in accordance with pile arrangement.