• 한국측량학회지
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• 제23권1호
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• pp.69-76
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• 2005

본 연구의 목적은 INCA2 카메라와 V-STARS 시스템으로 구성된 산업사진측량 시스템을 이용하여 현장 산업측정 조건에서 강박스거더의 측정을 실시하고, 그 측정 정확도를 평가하는데 있다. 실험을 위하여 코드타겟, 테이프타겟, 에지타겟 및 타겟어뎁터를 이용하였으며, 강박스 거더 부재면과 면사이의 거리, 부재와 리브간의 거리, 가조립을 위한 볼트구멍의 정확한 위치 및 부재면과 면 사이의 교차 각도 등을 측정 대상으로 하였다. 실험결과 본 연구에서 제안한 산업사진측량 기법으로 교량용 강박스 거더를 매우 정확하고, 신속하게 측정할 수 있었다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.974-981
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• 2005

Because general laboratory tests for sand compaction pile method including unit-cell test device have fixed outside diameter, as area replacement ratio increase, diameter of sand pile increase. These condition can bring about overestimation of stiffness of composite ground. In addition, existing large soil box which consist of bellows type loading plate can occur serious mistake in checking the amount of drained water because there are additional drainage along the inside wall in device. Overcoming these shortcoming, this paper developed modified large scale soil box consist of piston type load plate. In this study, using this device, series of modified large scale soil box tests were performed, and investigated the settlement and stress transportation characteristics with area replacement ratio in sand compaction pile method.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제16권1호
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• pp.27-35
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• 2016

Black-box classifiers, such as artificial neural network and support vector machine, are a popular classifier because of its remarkable performance. They are applied in various fields such as inductive inferences, classifications, or regressions. However, by its characteristics, they cannot provide appropriate explanations how the classification results are derived. Therefore, there are plenty of actively discussed researches about interpreting trained black-box classifiers. In this paper, we propose a method to make a fuzzy logic-based classifier using extracted rules from the artificial neural network and support vector machine in order to interpret internal structures. As an object of classification, an anomalous propagation echo is selected which occurs frequently in radar data and becomes the problem in a precipitation estimation process. After applying a clustering method, learning dataset is generated from clusters. Using the learning dataset, artificial neural network and support vector machine are implemented. After that, decision trees for each classifier are generated. And they are used to implement simplified fuzzy logic-based classifiers by rule extraction and input selection. Finally, we can verify and compare performances. With actual occurrence cased of the anomalous propagation echo, we can determine the inner structures of the black-box classifiers.

• Computers and Concrete
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• 제15권3호
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• pp.461-471
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• 2015

The permeability is the most direct indicator to reflect the durability of concrete, and the testing methods based on external electric field can be used to evaluate concrete permeability rapidly. This study aims to use an experiment method to accurately predict the permeability of concrete box beam during service. The ion migration experiments and concrete surface resistivity are measured to evaluate permeability of five concrete box beams, and the relations between these results in service concrete and electric flux after 6 hours by ASTM C1202 in the laboratory are analyzed. The chloride diffusion coefficient of concrete, concrete surface resistivity and concrete 6 hours charge have good correlation relationship, which denote that the chloride diffusion coefficient and the surface resistivity of concrete are effective for evaluating the durability of concrete structures. The chloride diffusion coefficient of concrete is directly evaluated permeability of concrete box beam in service and may be used to predict the service life, which is fit to engineering applications and the concrete box beam is non-destructive. The concrete surface resistivity is easier available than the chloride diffusion coefficient, but it is directly not used to calculate the service life. Therefore the mathematical relation of the concrete surface resistivity and the concrete chloride diffusion coefficient need to be found, which the service life of reinforced concrete is obtained by the concrete surface resistivity.

• 한국인터넷방송통신학회논문지
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• 제21권2호
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• pp.1-6
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• 2021

본 논문에서는 C# 언어를 이용하여 CCTV 영상보안 시스템의 효율적인 구현을 제안한다. 제안한 방법에서는 AES 알고리듬의 각 라운드 과정에서 요구되는 지연시간의 최소화를 위한 합성체 기반의 S-Box를 설계하고, 이를 기반으로 한 영상보안 시스템을 GF(((22)2)2) 상에서 구현한다. 또한, 메모리 공간의 최소화를 위해서 각 라운드 변환 및 키 스케쥴링 과정에서 필요한 S-Box를 공동으로 사용하도록 설계한다. 성능평가를 통하여 기존의 방법 보다 제안한 방법이 보다 효율적임을 확인하였다. 제안한 CCTV 영상보안 시스템은 Visual Studio 2010을 사용하여 C# 언어로 구현하였다.

• Structural Engineering and Mechanics
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• 제75권4호
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• pp.507-518
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• 2020

With the rapid development of rail transit, rail transit noise needs to be paid more and more attention. In order to accurately and effectively analyze the characteristics of low-frequency noise, a prediction model of vibration of box girder was established based on the hybrid FE-SEA method. When the train speed is 140 km/h, 200 km/h and 250 km/h, the vibration and noise of the box girder induced by the vertical wheel-rail interaction in the frequency range of 20-500 Hz are analyzed. Detailed analysis of the energy level, sound pressure contribution, modal analysis and vibration loss power of each slab at the operating speed of 140 km /h. The results show that: (1) When the train runs at a speed of 140km/h, the roof contributes more to the sound pressure at the far sound field point. Analyzing the frequency range from 20 to 500 Hz: The top plate plays a very important role in controlling sound pressure, contributing up to 70% of the sound pressure at peak frequencies. (2) When the train is traveling at various speeds, the maximum amplitude of structural vibration and noise generated by the viaduct occurs at 50 Hz. The vibration acceleration of the box beam at the far field point and near field point is mainly concentrated in the frequency range of 31.5-100 Hz, which is consistent with the dominant frequency band of wheel-rail force. Therefore, the main frequency of reducing the vibration and noise of the box beam is 31.5-100 Hz. (3) The vibration energy level and sound pressure level of the box bridge at different speeds are basically the same. The laws of vibration energy and sound pressure follow the rules below: web

• Steel and Composite Structures
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• 제33권4호
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• pp.489-507
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• 2019

In order to obtain high bearing capacity and good ductility simultaneously, a structural column with hybrid normal and high strength steel (HNHSS) welded box section has been developed. Residual stress is an important factor that can influence the behaviour of a structural member in steel structures. Accordingly, the magnitudes and distributions of residual stresses in HNHSS welded box sections were investigated experimentally using the sectioning method. In this study, the following four box sections were tested: one normal strength steel (NSS) section, one high strength steel (HSS) section, and two HNHSS sections. Based on the experimental data from previous studies and the test results of this study, the effects of the width-to-thickness ratio of plate, yield strength of plate, and the plate thickness of the residual stresses of welded box sections were investigated in detail. A unified residual stress model for NSS, HSS and HNHSS welded box sections was proposed, and the corresponding simplified prediction equations for the maximum tensile residual stress ratio (${\sigma}_{rt}/f_y$) and average compressive residual stress ratio (${\sigma}_{rc}/f_y$) in the model were quantitatively established. The predicted magnitudes and distributions of residual stresses for four tested sections in this study by using the proposed residual stress model were compared with the experimental results, and the feasibility of this proposed model was shown to be in good agreement.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.899-903
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• 2004

A limit switch box is used for a indicator of a valve actuator. This device indicates an opening and closing of a valve or throttle in a valve actuator. In ship, equipments are required safe and robust because of a rough environment and a specific condition during a voyage. However, the limit switch box is used in an indoor environment generally. Thus, a new limit switch box must be developed which can be used at an outdoor environment. This study designed the limit switch box. The housing of the limit switch box was made by an aluminium die cast method with surface painting after anodizing or chromate coating. In order to evaluate the endurance of the housing, the endurance tests against salt water have been conducted. Experiment results showed that the proposed device provides a reliable performance against salt water.

• 한국미생물·생명공학회지
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• 제27권6호
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• pp.440-445
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• 1999

In order to investigate structure-antibiotic activity relationships of brevinin-1 and thanatin containing Rana box composed of basic loop formed by disulfide bridge in their arboxy terminus, thanatin, brevinin 1 and their analogues (T-B1, T-B2 and B-T) in which their Rana box sequence exchanged was designed and synthesized by the solid phase method using Fmoc-chemistry. The basic sequence of Rana box of thanatin had more significant effect on both antibacterial and antifungal activity than that of brevinin 1. The tail sequence (QRM) of thanatin was found to be important in its antibacterial and antifungal activity. Rana box sequence of brevinin-1 did not have a significant effect on its antitumor and phospholipid vesicle-aggregating activities. Brevinin-1 showed stronger $\alpha$-helical structure in the membrane-mimicking environment such as SDS micelle than thanatin. A remarkable increase in a-helicity of bervinin-1 plays more important role in antibiotic activity than that of thanatin. Furthermore, antibacterial activity of thanatin against E. coli resulted from the disruptive effect against the outer cell membrane of E. coli.

• 한국전산구조공학회논문집
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• 제15권4호
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• pp.557-566
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• 2002

본 논문에서는 강상자형교의 바닥판과 주형에 대한 생애주기비용(Life-Cycle Cost : LCC)를 고려한 최적설계 방법을 제안하였다. 생애주기비용의 최적설계 문제는 초기비용, 유지관리비용 그리고 강도와 처짐 그리고 균열에 대한 파손 기대비용의 최소화 문제로 정식화할 수 있다. 기존의 재래적인 설계방법과의 비교를 동해서 강상자형교의 생애주기비용 최적설계의 우수성을 입증하였다. 또한 수치적인 결과의 고찰을 통하여 LCC에 근거한 최적설계가 여타의 설계방법들보다 좀 더 합리적이고 경제적이며 안전한 설계를 유도하는 것으로 분석되었다.