• 한국전자통신학회논문지
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• 제12권4호
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• pp.591-598
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• 2017

현재 무인항공기의 기술 변화와 시장 규모는 발 빠르게 확산되고 있다. 활용 범위의 확대로 드론을 쉽게 접할 수 있게 되면서 조종자의 조종 미숙으로 인한 피해가 발생한다. 이러한 문제 발생으로 인한 피해를 최소화하기 위해서 드론의 안정적인 비행 능력이 요구되며 이를 위하여 모터의 안정적인 속도 제어가 요구된다. 따라서 본 논문에서는 모터의 제어 방안으로 Arduino를 주 제어장치로 사용하였으며 기체의 자세 안정화를 위하여 가속도 센서와 자이로 센서를 사용하였다. 또한, 초음파 센서를 드론에 탑재하여 일정 높이에서 호버링이 가능하도록 하였다. 안드로이드 앱을 이용하여 드론을 제어하였으며 그 결과 0~2m 범위의 지정한 위치에서 안정적으로 호버링이 가능함을 확인하였다.

• 실천공학교육논문지
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• 제12권1호
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• pp.23-29
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• 2020

ICT의 발전, ICT 기기와 서비스의 다양화, 소셜 미디어의 확장 등으로 생성된 데이터들은 그 데이터의 양, 다양성, 속도 등으로 특징 지워지는 빅데이터로 분류되고 있다. 빅데이터의 활용 확산은 모든 산업에서 데이터 분석에 의한 현상태 파악, 미래의 예측, 적용할 기회의 창출 등의 효과를 기대하고 있다. 그러나 이러한 일들이 이루어지려면 그 일을 수행할 인력의 배출이 절실하나 국내에서는 아직까지도 전문 인력 양성 기관이나 교육과정이 부족한 현실이다. 이에 본 사례연구에서는 국내의 빅데이터 인력양성 교육의 상태를 조사하고, 빅데이터에 대한 인식제고에 따라 교육의 필요성이 대두되고 있는 이 때 균형잡힌 전문 인력을 육성하기 위해서 어떤 단계와 수준으로 교육되고 있는지를 알아보고 학생들의 가치를 높일 수 있는 방안을 고민하는 계기를 마련하고자 한다.

• 한국농촌생활과학회지
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• 제9권1호
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• pp.33-42
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• 1998

The purpose of this study was to find out the dietary attitudes and behaviors, intake frequencies of food groups, health-related opinions and practices, and sociodemographic characteristics of housewives in Wonju-Gun rural area. Interviewers asked 413 housewives about obove informations and then recorded. The results were as followes : Using the factor analysis processing, 17 questions about dietary attitudes and behaviors were categorized into 5 groups such as fidelity of diet, the healthful dietary attitudes, the eating practices concerning about items and amount, eating speed and the extent of coincidence in food preference within a family. The role of the housewives was a major factor affecting the dietary attitudes and behaviors. Those who work as housewives and farmers concurrently had good dietary practices concerning about items and amount, but they were interested about health-directed dietary attitudes at a significantly lower level. Food frequencies of 9 groups, animal protein food, fruits and vegetables, milk and milk products, small fishes such as anchovy, soybean curd and beans, seaweeds, vegetable oil, frying food, soybean paste were significantly associated with subjects' age, role, and education and income level. Whether or not intake of soybean paste was considered. protein food intake was altered, and the difference between two situations increased much more as age was higher. We noticed that intake of soybean paste improved the status of protein nutrition. Our subjects ate calcium sources and dishes using vegetable oil insufficiently. Those who had much interests for good health, revealed to be an active practitioner in the aspects of healthful dietary attitudes, but fidelity of diet, eating practices concerning about items and amount showed significant association with balanced life style.

• 대한토목학회논문집
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• 제31권2D호
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• pp.203-208
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• 2011

우리나라 대부분의 도시는 지속적인 개발에 따라 교통 수요가 급속도로 증가하고 있다. 이에 따라 도로용량 증대를 위한 도로 확장 등이 이루어지고 있으나 동일 교통 특성을 지니는 구간 내에서 일부 구간만의 확장으로 전체적인 주행 차로 수 균형이 유지되고 있지 않아 차량 소통 및 교통안전 측면에서 문제가 발생하고 있다. 본 연구에서는 국도 32호선 대전광역시 통과 구간 중 직진 주행 차로 수가 일치하지 않는 구간을 중심으로 차로 수 불일치에 따른 문제점을 분석하고 차로 수를 일치하였을 경우의 효과에 대한 분석을 실시하였다. 분석 방법으로는 마이크로 시뮬레이션인 VISSIM을 활용하였으며 개선 전후의 평균 통행속도, 지체도, 상충 수 등을 비교 분석하였다. 분석결과 주행 차로 수 일치에 따라 지체도가 감소하고 평균 통행속도가 증가하였다. 본 연구결과는 주행 차로 수 일치의 중요성을 부각시켜 향후 도로확장 등 개선 공사 시행에서 병목현상 개선 및 차량 상충 감소에 기여할 것으로 판단된다.

• Structural Engineering and Mechanics
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• 제74권1호
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• pp.1-18
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• 2020

For the large deformation of shear walls under vertical and horizontal loads, there are difficulties in obtaining accurate simulation results using the response analysis method, even with fine mesh elements. Furthermore, concrete material nonlinearity, stiffness degradation, concrete cracking and crushing, and steel bar damage may occur during the large deformation of reinforced concrete (RC) shear walls. Matrix operations that are involved in nonlinear analysis using the traditional finite-element method (FEM) may also result in flaws, and may thus lead to serious errors. To solve these problems, a planar four-node element was developed based on vector mechanics. Owing to particle-based formulation along the path element, the method does not require repeated constructions of a global stiffness matrix for the nonlinear behavior of the structure. The nonlinear concrete constitutive model and bilinear steel material model are integrated with the developed element, to ensure that large deformation and damage behavior can be addressed. For verification, simulation analyses were performed to obtain experimental results on an RC shear wall subjected to a monotonically increasing lateral load with a constant vertical load. To appropriately evaluate the parameters, investigations were conducted on the loading speed, meshing dimension, and the damping factor, because vector mechanics is based on the equation of motion. The static problem was then verified to obtain a stable solution by employing a balanced equation of motion. Using the parameters obtained, the simulated pushover response, including the bearing capacity, deformation ability, curvature development, and energy dissipation, were found to be in accordance with the experimental observation. This study demonstrated the potential of the developed planar element for simulating the entire process of large deformation and damage behavior in RC shear walls.

• Physical Therapy Rehabilitation Science
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• 제2권1호
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• pp.12-20
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• 2013

Objective: To determine the energy consumed and muscle use during dance compared to different standard exercise devices. Design: Longitudinal study. Methods: Fifteen female subjects were evaluated to assess the energy cost and muscle activity during a 20 minute dance video compared to treadmill, elliptical track and bicycle ergometry. The later 3 forms of exercise were accomplished in four, 5 minute bouts at different intensities of exercise. Subjects were in the age range of 22-24 years old, were free of cardiovascular disease and did not have any neurological injuries. They were not sedentary and exercised at least twice a week. During the exercise, muscle activity was measured by the electromyogram recorded by surface electrodes on 6 muscle groups. A Cosmed metabolic cart was used to measure oxygen consumption during the exercise. Results: The aerobic dance video that was tested here was equivalent to a hard workout on any of the 3 exercise modalities. The dance routine was equivalent in terms of energy consumed to running at 225 watts of work or running for 20 minutes at a speed of 2 meters per second (4.47 miles per hour). Compared to the bicycle, it was equivalent to cycling at 112 watts for 20 minutes (2.25 kpm), and for the elliptical trainer, dance was equivalent to 435 watts. Concerning muscle use, the dance routine was the most balanced for upper, core and lower body muscles. Although the elliptical trainer was close, it required muscle less muscle use. Conclusion: A good dance video can be more effective than standard exercise equipment.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 1999년도 추계종합학술대회
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• pp.161-166
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• 1999

이동 통신의 세계적 흐름은 디지털화, 고속화 그리고 대용량화의 추세로 나아가고 있다. 또한 한정된 주파수 자원을 효율적으로 이용하기 위하여 대역확산 방식이 그 주를 이루고 있다. 본 연구에서는 고속 주파수도약 방식을 이용하였다. 잡음 등의 여러 가지 문제점을 가지고 있는 PLL(Phase Lock Loop) 대신, PLL의 단점을 최소화할 수 있는 디지털 소자인 직접 디지털 주파수합성기(DDS : Direct Digital Synthesizer)를 사용하여 FFH 시스템 송신부의 주파수합성기를 설계하였다. PLL를 이용하여 고속 주파수 도약시스템을 설계하는 경우, PLL의 settling time의 설정과 요구되는 RF대역폭등의 설계사양을 만족시키기가 어려우며 평형변조기 사용에 의한 회로의 복잡성으로 인한 제약이 따르게 된다. 본 연구에서는 DDS를 이용하여 고속 주파수도약 시스템을 설계하기 위한 성능평가에 대하여 연구하였으며, 오율 개선의 해석과 도약율 1M hps, 5MHz RF 대역폭의 고속 주파수 도약이 가능한 시스템을 설계하고 성능을 평가하였다.

• 수산경영론집
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• 제52권2호
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• pp.55-67
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• 2021

Global warming affects critical natural resources, one of which is the oceans that occupy 70% of the total cover of the earth. In other words, ocean warming is a subset of global warming which needs to be addressed urgently. Purple laver (pyropia spp.) is one of the most vulnerable items to climate change although it is a major export product of Korean fisheries. The purpose of this study is to analyze the causality of how climate change caused by global warming affects the increase or decrease of PLP (purple laver production). The target area for analysis was set to Maro-hae between Jindo-gun and Haenam-gun. We selected marine environmental factors and meteorologic factors that could affect PLP as variables, as well as co-integration tests to determine long-term balance, and the Granger causticity tests. As a result, PLP and marine environmental factors WT (water temperature), pH, and DO confirmed that long-term equilibrium relationships were established, respectively. However, there is only causality with WT and it is confirmed that there is only a correlation between pH and DO (dissolved oxygen). There was no long-term equilibrium relationship between PLP and HDD (heating degree days) and there is a causal effect that HDD affects PLP; however, it was less clear than that of WT. The relationship between PLP and RF (rainfall), WS (wind speed), SS (percentage of sunshine), and FF (farm facilities) was all balanced in the long term, and causality exists. Based on the results of the analysis, policy proposals were made.

• 한국염색가공학회지
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• 제35권1호
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• pp.8-19
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• 2023

Silicone rubber is widely used in most industries due to diverse advantages like heat stability, UV stability, durability, chemical resistance, environment friendliness, inertness and so on. But there is limitation to expand applications due to relatively weak rubber strengths such as tensile strength and tear strength, especially in fabric coating applications. The purpose of this study is to find influence of coating agent on performances of rubber and coated fabrics and their correlation according to different crosslinking densities of silicone rubbers. Addition cure type of silicones were formulated using crosslinked MQ-type silicone resin consisting of M (R₃SiO_1/2) and Q (SiO_4/2) and linear polymers. Raw materials used were; 1) linear vinyl endblocked polymers and vinyl functional MQ resin as main polymers, 2) linear silicone hydride polymers as crosslinkers, 3) platinum catalyst and 4) inhibitor to control curing speed. Rubber specimens were prepared to check mechanical strength using universal testing machine (UTM). Crosslinking density was calculated using Flory-Rhener equation using solvent swelling method. Differential scanning calorimetry (DSC) and scanning electron microscope (SEM-EDS) were used to characterize rubbers. Consequently, it was found that physical properties of silicone rubbers and coated fabrics can be expected by crosslinking density of rubbers. Silicone rubber formulations that contain 20 ~ 30 wt% of vinyl MQ resin showed strongest balanced performances.

• 한국전자통신학회논문지
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• 제19권1호
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• pp.309-316
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• 2024

얼굴 인식 기술은 다양한 분야에서 활용되고 있지만, 이는 사진 스푸핑과 같은 위조 공격에 취약하다는 문제를 가지고 있다. 이를 극복하기 위한 여러 연구가 진행되고 있지만, 대부분은 멀티모달 카메라와 같은 특별한 장비를 장착하거나 고성능 환경에서 동작하는 것을 전제로 하고 있다. 본 연구는 얼굴 인식 위조 공격 문제를 해결하기 위해, 특별한 장비 없이 일반적인 웹캠에서 동작할 수 있는 LH-FAS v2를 제안한다. 제안된 방법에서는, 머리 자세 추정에는 FSA-Net을, 얼굴 식별에는 ArcFace를 활용하여 사진 스푸핑 여부를 판별한다. 실험을 위해, 사진 스푸핑 공격 비디오로 구성된 VD4PS 데이터셋을 제시하였으며, 이를 통해 LH-FAS v2의 균형 잡힌 정확도와 속도를 확인하였다. 본 방법은 향후 사진 스푸핑 방어에 효과적일 것으로 기대한다.