• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 춘계학술대회
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• pp.401-403
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• 2015

128비트 블록암호 알고리듬 LEA(Lightweight Encryption Algorithm)의 효율적인 하드웨어 설계에 대해 기술한다. 저전력, 저면적 구현을 위해 라운드블록과 키 스케줄러의 암호화와 복호화 연산의 하드웨어 자원이 공유되도록 설계하였다. 키 스케줄러 레지스터의 구조를 개선하여 키 스케줄링에 소요되는 클록 사이클 수를 감소시켰으며, 이를 통해 암호화/복호화 성능을 향상시켰다. 설계된 LEA 프로세서는 FPGA 합성결과, 2,364 슬라이스로 구현되었으며, 113 MHz로 동작하여 128/192/256비트 마스터키 길이에 대해 각각 181/162/109 Mbps의 성능을 갖는 것으로 평가되었다.

• 설비공학논문집
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• 제29권5호
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• pp.269-277
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• 2017

This study consists of an analysis of pre-existing ceiling construction systems as well as the development of a replacement unitary, lightweight steel ceiling system and related legal standards. Based on the material conditions and progression of the study, appropriate components were chosen and details were modified by mock-up test. A final study model was evaluated for performance and adaptability based on four parameters (indoor environment, constructability, budget economy, and aesthetics) and compared to the pre-existing ceiling system. As a result of the initial study, a lightweight steel design was created consisting of a reinforced structure with modular bars and entry holes for components. This system was hung directly on the suspension structure. The new design increased lighting and acoustic performance adapted to an indoor environment. Moreover, the speed of construction was increased by approximately 30%, the cost was decreased by approximately 20%, and ceiling aesthetics were improved.

• Advances in concrete construction
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• 제13권4호
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• pp.291-305
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• 2022

The present investigation deals with the production of the innovative lightweight fly ash angular aggregates (FAA) first time in India using local class 'F' fly ash, its characterization, and exploring the potential for its utilization as alternative coarse aggregates in structural concrete applications. Two types of aggregates are manufactured using two different kinds of binders. The manufacturing process involves mixing fly ash, binder, and water, followed by the briquetting process, sintering and crushing them into suitable size aggregates. Tests are conducted on fly ash angular aggregates to measure their physical properties such as crushing value, impact value, specific gravity, water absorption, bulk density, and percentage of voids. Study shows that the physical parameters are significantly enhanced as compared to commercially available fly ash pellets (FAP). The developed FAA are used in concrete vis-à-vis conventional granite aggregates and FAP to determine their compressive, split tensile and flexural strengths. Although being lightweight, the strength parameters for concrete containing FAA are well compared with conventional concrete. This might be due to the high pozzolanic reaction between fly ash angular aggregates and cement paste. Also, RCC beams are cast and the load-deflection behaviour and ultimate load carrying capacity signify that FAA can be suitably used for RCC construction. Hence, the utilization of fly ash as angular aggregates can reduce the dead load of the structure and at the same time serves as a solution for fly ash disposal and mineral depletion problem.

• International Journal of Contents
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• 제18권2호
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• pp.68-80
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• 2022

The health of the human heart is commonly measured using ECG (Electrocardiography) signals. To identify any anomaly in the human heart, the time-sequence of ECG signals is examined manually by a cardiologist or cardiac electrophysiologist. Lightweight anomaly detection on ECG signals in an embedded system is expected to be popular in the near future, because of the increasing number of heart disease symptoms. Some previous research uses deep learning networks such as LSTM and BiLSTM to detect anomaly signals without any handcrafted feature. Unfortunately, lightweight LSTMs show low precision and heavy LSTMs require heavy computing powers and volumes of labeled dataset for symptom classification. This paper proposes an ECG anomaly detection system based on two level BiLSTM for acceptable precision with lightweight networks, which is lightweight and usable at home. Also, this paper presents a new threshold technique which considers statistics of the current ECG pattern. This paper's proposed model with BiLSTM detects ECG signal anomaly in 0.467 ~ 1.0 F₁ score, compared to 0.426 ~ 0.978 F₁ score of the similar model with LSTM except one highly noisy dataset.

• Coupled systems mechanics
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• 제12권4호
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• pp.315-335
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• 2023

The building sector has seen a huge increase in the use of lightweight concrete recently, which might result in saving in both cost and time. As a result, the study has been done on various types of concrete, including lightweight (LC), heavyweight (HC), and ordinary concrete (OC), to understand how they react to earthquake loads. The comparisons between their responses have also been taken into account in order to acquire the optimal reaction for various materials in building work. The findings demonstrate that LWC building models are more earthquake-resistant than the other varieties due to the reduction in building weight which can be a curial factor in the resistance of earthquake forces. Another crucial factor that was taken into study is the combination of various types of concrete [HC, LC, and OC] in the structural components. On the other hand, the bending moments and shear forces of LC had reduced to 17% and 19%, respectively, when compared to OC. Otherwise, the bending moment and shear force demand responses in the HC model reach their maximum values by more than 34% compared to the reference model OC. In addition, the results show that the LCC-OCR (light concrete column and ordinary concrete roof) and OCC-LCR (ordinary concrete for the column and light concrete for the roof) models' responses have fewer values than the other types.

• International Journal of Internet, Broadcasting and Communication
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• 제15권4호
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• pp.250-260
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• 2023

In this paper, we designed a IoT(Internet of Things) sensor block embedded lightweight house deck structures that can be implemented using Carbon Fiber Reinforced Polymer(CFRP). Deck-Sensor interconnection interface block via IoT connectivity Hub that can mount external environmental sensors such as fire sensors on the Deck body itself was also proposed. Additionally we described the configuration of devices for data acquisition and analysis based on IoT environmental detection sensors that can be commonly installed and used on these deck bodies. On the other hand, received sensing data based monitoring user interface(UI) also developed and used for sensing data analysis for remote monitoring center. Through the implementation of such IoT-based sensor data transmission and collection analysis devices and UI software, this paper confirmed the availability of CFRP based lightweight House deck structure and possibility of CFRP deck-based IoT sensor data networking and analysis functions.

• 한국CDE학회논문집
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• 제18권4호
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• pp.258-266
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• 2013

In shipbuilding, 2D manufacturing drawings are crucial for building a ship. Even various types of 3D models are being utilized for supporting ship manufacturing, which does not reduce the importance of 2D drawings. Recently things are changing in the shipbuilding industry. To reduce the number of 2D drawings or to reduce the quantity of information contained in 2D drawings, some attempts that can substitute for 2D drawings are being made. One of the attempts is to visualize lightweight 3D manufacturing models in a mobile device. In this paper, a method for displaying lightweight 3D models of a ship in an Android based device is introduced. To overcome the problem with parsing JT files in Android system, JT files are parsed in a Windows based server and as-simple-as-possible visualization data are transmitted to an Android based viewer. A comparison result with a commercial system is also given.

• 한국생산제조학회지
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• 제21권2호
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• pp.241-245
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• 2012

In this study, one type of circular shaped composite tube was used, combined with reinforcing foam and without foam. Furthermore, CFRP (Carbon Fiber Reinforced Plastic) circular member manufactured from CFRP prepreg sheet for lightweight design. CFRP is an anisotropic material which is the most widely adapted lightweight structural member. The crashworthy behavior of circular composite material tubes subjected to static axial compression under same conditions is reported in this paper. The collapse mode during the failure process were observed and analyzed. The behavior of polymeric foams to the tubes crashworthiness were also investigated.

• 한국생산제조학회지
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• 제23권2호
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• pp.152-156
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• 2014

Lightweight materials such as aluminum and magnesium have recently received much attention in the automotive industries because of environmental and fuel-efficiency concerns. Using the powder metallurgy (PM) process for these materials creates significant opportunities for the cost-effective manufacture of lightweight automotive parts. In the present study, an Al-Cu-Mg alloy was fabricated using conventional PM processes. Primarily, the effects of the alloying elements on the sintering characteristics and mechanical behavior after heat treatment were investigated. A microstructural analysis was performed using an optical microscope and a scanning electron microscope to investigate the behavior of liquid phase sintering, including the formation of precipitates. The dependence of the mechanical behavior on the alloying elements was evaluated based on the transverse rupture strength.

• 소성∙가공
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• 제31권5호
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• pp.267-272
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• 2022

A dual-phase structure refers to a material with two different phases of components or crystal structures. In this study, we analyze the stress distributions for harmonic and composite structured materials which are a kind of dual-phase structure materials. The finite element method (FEM) was used to progress compression test to analyze the strain distribution, and rather than constituted of a fully dense material, a dual-phase structure was designed to make a lightweight structure that has different shapes and volumes of vacancy in each case. As a result of each case, the dual-phase structured materials showed different stress distribution patterns and based on this, the cause was identified through the research.