• 한국지능시스템학회논문지
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• 제20권1호
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• pp.76-80
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• 2010

급변하는 정보의 홍수 속에서 정보의 보안과 이를 가공하고 전송하는 것이 중요한 과제로 떠오르고 있다. 초기 정보보호이론과 암호화 전송단계에서는 간단한 치환과 수학적 계산 알고리즘을 적용한 암 복호화 과정을 이용하였다. 완벽한 정보보호는 One-time pad를 이용하는 것이나 이를 적용하기에는 하드웨어와 금전적 손실이 너무 크기에 실난수가 아닌 난수성을 만족하는 의사난수를 사용하고 있다. 본고에서 제안하는 변형 시리얼 테스트는 의사난수성을 입증하는 테스트 중 시리얼테스트에서 변형된 것으로 연산속도와 효율성 면에서 보다 더 강력한 난수성임을 입증하고 있다.

• 유통과학연구
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• 제17권12호
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• pp.63-70
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• 2019

Purpose: This study was to propose effective deployment of automatic external defibrillators (AEDs) installed at general supermarkets. Research design, data, and methodology : We conducted interview and data surveys on 72 large distributors in Seoul and Gyeonggi province in South Korea. The content of this survey was consisted of general status on the general supermarkets, AED deployment and management regarding public access defibrillation (PAD). G^⁎Power (v 3.1.9.4; Universität Kiel, Kiel, Germany) was also used to analyze statistical power. Radius and actual distance, radius and retrieval time were compared by t-test at α=.05. respectively. Results : Difference between the radius (102.7 meters) and the actual distance (187.8 meters) was 85.1m, it had statistically significant difference (p<.001). The actual distance was longer compared to the radius distance. Difference between the radius (114.1 seconds) and the retrieval time (208.7 seconds) was 94.6s, it had statistically significant difference (p<.001). The retrieval time took longer compared to the radius time as well. Conclusions : The finding shows that only 45.9% of the general supermarkets are satisfied with the actual AED coverage within 3 minutes. This needs to enhance AED deployment to reduce defibrillation time and AED management to boost application in South Korea.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 추계학술대회
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• pp.489-491
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• 2013

본 논문에서 Processing 언어를 이용하여 아두이노 기반의 컴퓨터와의 통신을 이용하여 소리를 내는 전자드럼을 설계 하였다. 먼저 피에조 센서를 이용해서 드럼패드를 구현한다. 이때 드럼패드는 센서가 파손되지 않도록 충격을 완화시킬 수 있는 구조로 제작하였다. 이 패드를 아두이노와 연결하여 센서가 충격을 받으면 감지한 신호를 아두이노로 보낸다. 그러면 신호를 받은 아두이노는 컴퓨터에 신호를 전송하고 신호를 받은 컴퓨터는 저장되어 있는 드럼소리를 출력한다. 이러한 구조를 통해서 마이크로 컨트롤러와 컴퓨터의 통신 기술을 이용한 많은 응용 가능한 부분이 있을 것으로 사료된다.

• 접착 및 계면
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• 제5권2호
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• pp.31-42
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• 2004

Many animals possess on their legs adhesive pads, which have undergone evolutionary optimization to be able to attach to variable substrates and to control adhesive forces during locomotion. Insect adhesive pads are either relatively smooth or densely covered with specialized adhesive hairs. Theoretical models predict that adhesion can be increased by splitting the contact zone into many microscopic, elastic subunits, which provides a functional explanation for the widespread 'hairy' design. In many hairy and all smooth attachment systems, the adhesive contact is mediated by a thin film of liquid secretion between the cuticle and the substrate. By using interference reflection microscopy (IRM), the thickness and viscosity of the secretion film was estimated in Weaver ants (Oecophylla smaragdina). 'Footprint' droplets deposited on glass are hydrophobic and form low contact angles. IRM of insect pads in contact showed that the adhesive liquid is an emulsion consisting of hydrophilic, volatile droplets dispersed in a persistent, hydrophobic phase. I tested predictions derived from film thickness and viscosity by measuring friction forces of Weaver ants on a smooth substrate. The measured friction forces were much greater than expected assuming a homogenous film between the pad and the surface. The findings indicate that the rubbery pad cuticle directly interacts with the substrate. To achieve intimate contact between the cuticle and the surface, secretion must drain away, which may be facilitated by microfolds on the surface of smooth insect pads. I propose a combined wet adhesion/rubber friction model of insect surface attachment that explains both the presence of a significant static friction component and the velocity-dependence of sliding friction.

• ETRI Journal
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• 제33권3호
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• pp.335-343
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• 2011

The pad pitch of modern radio frequency integrated circuits is in the order of few tens of micrometers. Connecting a large number of high-speed I/Os to the outside world with good signal fidelity at low cost is an extremely challenging task. To cope with this requirement, we need reflection-free transmission lines from an on-chip pad to on-board SMA connectors. Such a transmission line is very hard to design due to the difference in on-chip and on-board feature size and the requirement for extremely large bandwidth. In this paper, we propose the use of narrow tracks close to chip and wide tracks away from the chip. This narrow-to-wide transition in width results in impedance discontinuity. A step change in substrate thickness is utilized to cancel the effect of the width discontinuity, thus achieving a reflection-free microstrip. To verify the concept, several microstrips were designed on multilayer FR4 PCB without any additional manufacturing steps. The TDR measurements reveal that the impedance variation is less than 3 ${\Omega}$ for a 50 ${\Omega}$ microstrip and S11 better than -9 dB for the frequency range 1 GHz to 6 GHz when the width changes from 165 ${\mu}m$ to 940 ${\mu}m$, and substrate thickness changes from 100 ${\mu}m$ to 500 ${\mu}m$.

• 디지털융복합연구
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• 제11권11호
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• pp.389-395
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• 2013

IT 기술과 의료기술이 융합되면서 환자의 체내에 의료장비를 부착한 환자의 수가 증가하고 있다. 그러나 환자의 생체정보를 제 3자가 악의적으로 도청 및 변경하는 문제점이 발생하고 있다. 본 논문에서는 환자와 병원관계자 사이에서 환자의 생체정보를 제3자가 도청하거나 변조없이 키를 공유하도록 양자 암호 기반의 키 분배 모델을 제안한다. 제안 모델의 양자 정보는 메시지 직접전달보다는 임의의 비트들을 전달하여 키를 공유하는 one-time pad 키를 사용한다. 또한, 제안 모델은 체내삽입장치의 생체정보가 제3자에게 불필요하게 노출되지 않아 환자의 익명성을 보장받는다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.390-391
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• 2006

This paper describes the design, fabrication and characteristics of a micromachined piezoelectric valve utilizing a multilayer ceramic actuator (MCA). The micromachined MCA valve, which uses a buckling effect, consists of three separate structures: the MCA, the valve actuator die and the seat die. The valve seat die with 6 trenches was made, and the actuator die, which is driven by the MCA under optimized conditions, was also fabricated. After Si wafer direct bonding between the seat die and the actuator die, the MCA was also anodically bonded to the seat/actuator die structure. A polydimethylsiloxane (PDMS) sealing pad was fabricated to minimize the leak rate. Finally, the PDMS sealing pad was also bonded to the seat die and the stainless steel package. The MCA valve shows a flow rate of 9.13 sccm at an applied DC voltage of 100 V with a 50% duty cycle and a maximum non-linearity of 2.24% FS. Therefore, the fabricated MCA valve is suitable for a variety of flow control equipment, as a medical bio-system and in the automobile industry.

• International journal of advanced smart convergence
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• 제10권4호
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• pp.183-197
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• 2021

Xiaohongshu is called China's Instagram and is leading overseas product purchases and culture sharing. The purpose of this study is to investigate the structural relationship between Xiaohongshu service quality, emotional response perceived by users, and adhesion to confirm the impact on Xiaohongshu's adhesion at a time when non-face-to-face activities due to COVID-19 have increased. This study distributed and collected questionnaires from October 1st to October 7th, 2021, targeting 210 online shopping mall users. The research results were derived from a total of 206 questionnaires, excluding 4 questionnaires such as omission of record contents, and the causal relationship of the existing PAD model was attempted to be reported by revising and supplementing the existing PAD model. As a result of the study, first, it was confirmed that design among service quality had a positive effect only on ventilation during the user's emotional response. Second, it was confirmed that information among service quality had a positive effect on pleasure and ventilation among users' emotional responses. Third, it was found that security among service quality had a positive effect on pleasure among users' emotional responses. Finally, it was found that pleasure and ventilation had a positive effect on adhesion in the user's emotional response. Based on this result, it is expected that it will be used for operation on other online platforms than the plan for the development of Xiaohongshu.

• 자동차안전학회지
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• 제13권3호
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• pp.32-40
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• 2021

Composite material is very attractive because it has excellent mechanical property and is possible to lightweight due to the low density. However, composite material is less used compared to other systems in the chassis system because it is very hard to solve NVH problem when composite material is applied to vehicle. Especially, reducing squeal noise of composite brake system is essential to apply it to vehicle successfully. In this paper, we present a new solution to reduce squeal noise of composite brake system. To achieve this goal, we analyze main causes of noise using RCA (Root Cause Analysis), CA (Contradiction Analysis) and sequentially get IFR (Ideal Final Result) to solve the problem. Next, we define the function of composite brake system and derive control factors and noise factors. A variety of tests for factors like chamfer, slot, damping shim, underlayer of brake pad are done. In addition, we analyze level of contribution for control factors theoretically. Finally, we get the effective solution for reducing squeal noise.

• 풍력에너지저널
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• 제14권4호
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• pp.13-20
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• 2023

A self-climbing crane (SCC) system is under development for the installation and maintenance of wind turbines. It can move vertically along the wind turbine tower by itself. One of the key components of the SCC system is the clamping pad to maintain a safe position on the wind turbine tower. The SCC system can maintain its position on the tower from the frictional force generated between the surfaces of the clamping pads and the tower. If the frictional force provided by the clamping pads are insufficient, the SCC system cannot stay in the vertical position on the tower. Therefore, the development of clamping pads with sufficient frictional force is very important for the SCC system. At the same time, the operation of the SCC system should not damage the paint coating of the wind turbine tower. In order to verify that the frictional force is sufficient and that frictional and compressive forces do not cause damage to the paint, a number of combined compression and shear loading tests were conducted using a test device prepared for this study. The details regarding the test specimens, test procedure, and test results are summarized in this paper.