• 수산해양기술연구
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• 제52권4호
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• pp.299-307
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• 2016

This study aims to investigate effects of the length of the buoy and sand bag line on the loss of webfoot octopus pot. A numerical modeling and simulation was carried out to analyze the process that the pot gear affected by wave using the mass spring model. Through the simulation, tensions of sand bag line under various condition were investigated by length of buoy and sand bag line. The drag force and coefficient k of an artificial shell used in the webfoot octopus pot was obtained from an experiment in a circular water channel, and the coefficient k was applied to the simulation. To verify the accuracy of the simulation model, a simple test was conducted into measuring a rope tension of a hanging shell under flow. Then, the test result was compared with the simulation. The lengths of the buoy line in the simulation were 1.12, 1.41, 1.80, 2.23, 2.69, and 3.17 times of water depth. The lengths of sand bag line were 10, 20, 30, and 40 meters, and conditions of water depth were 8, 15, 22 meters. 4 meter height and 8 second period of wave were applied to all simulations. As a results, the tension of the sand bag line was decreased as the buoy and sand bag line were increased. The minimum tension of the sand bag line was appeared in conditions that the length of the buoy line is twice of water depth and the sand bag line length is over 40 meters (except in case of depth 8 meters.).

• Smart Structures and Systems
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• 제22권4호
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• pp.413-424
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• 2018

The factors affecting the shear strength of the angle shear connectors in the steel-concrete composite beams can play an important role to estimate the efficacy of a composite beam. Therefore, the current study has aimed to verify the output of shear capacity of angle shear connector according to the input provided by Support Vector Machine (SVM) coupled with Firefly Algorithm (FFA). SVM parameters have been optimized through the use of FFA, while genetic programming (GP) and artificial neural networks (ANN) have been applied to estimate and predict the SVM-FFA models' results. Following these results, GP and ANN have been applied to develop the prediction accuracy and generalization capability of SVM-FFA. Therefore, SVM-FFA could be performed as a novel model with predictive strategy in the shear capacity estimation of angle shear connectors. According to the results, the Firefly algorithm has produced a generalized performance and be learnt faster than the conventional learning algorithms.

• 대한약침학회지
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• 제3권2호
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• pp.1-25
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• 2000

We were trying to study the validity of Puffer fish's poison(Tetrodotoxin- TTX) to make a traditional Korean Medical treatment. The following conclusions were made after literary studies. 1. The first record of the puffer fish dates back 2000 years ago in the Chinese text Book of Mountain and Sea and other texts from the similar period. 2. Puffer fish's poison IS known as tetrodotoxin which is an amino perhydroquinazoline compound. It has a chemical formula of $C_{11}H_{17}N_3O_8$ in the hemiacetal structure and has the molecular weight of 319. 3. Tetrodotoxin (TTX) plays a role as potent neurotransmitter blocker by blocking the $Na^+$ -gate channel which hinders the influx of $Na^+$ ion into the cell. 4. Symptoms of the puffer fish poisoning ranges from blunted sense in the lips and tongue, occasional vomiting in the first degree to sudden descending of the blood pressure, apnea, and other critical conditions in the fourth degree. Intoxication of the puffer fish poison progresses at a rapid pace as death may occur after an hour and half up to eight hours in maximum. Typical death occurs after four to six hours. 5. Ways to treat the puffer fish poisoning include gastric irrigation, induce vomiting, purgation, intravenous fluid injection, and correcting electrolytic imbalance and acidosis. In cases of dyspnea, apply oxygen inhalation and conduct artificial respiration. 6. Tetrodotoxin (TTX) may be applied in treating brain disorders, ocular pain, excess pain in the large intestine and ileum, and relieving tension of the skeletal museles, neuralgia, rheumatism, arthritis, and etc. 7. In terms of Oriental medicine, the puffer fish poison has characteristics of sweet, warm, and poisonous. It's known efficacies are to tonify weakness, dispel damp, benefit the lower back, relieve hemorrhoid, kills parasites, remove edema, and so forth. And the puffer fish eggs processed with ginger are said to be effective against tuberculosis and lung cancer, thus, it's validity must be investigated and further research should be followed.

• Smart Structures and Systems
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• 제24권5호
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• pp.567-585
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• 2019

In the past two decades, structural health monitoring (SHM) systems have been widely installed on various civil infrastructures for the tracking of the state of their structural health and the detection of structural damage or abnormality, through long-term monitoring of environmental conditions as well as structural loadings and responses. In an SHM system, there are plenty of sensors to acquire a huge number of monitoring data, which can factually reflect the in-service condition of the target structure. In order to bridge the gap between SHM and structural maintenance and management (SMM), it is necessary to employ advanced data processing methods to convert the original multi-source heterogeneous field monitoring data into different types of specific physical indicators in order to make effective decisions regarding inspection, maintenance and management. Conventional approaches to data analysis are confronted with challenges from environmental noise, the volume of measurement data, the complexity of computation, etc., and they severely constrain the pervasive application of SHM technology. In recent years, with the rapid progress of computing hardware and image acquisition equipment, the deep learning-based data processing approach offers a new channel for excavating the massive data from an SHM system, towards autonomous, accurate and robust processing of the monitoring data. Many researchers from the SHM community have made efforts to explore the applications of deep learning-based approaches for structural damage detection and structural condition assessment. This paper gives a review on the deep learning-based SHM of civil infrastructures with the main content, including a brief summary of the history of the development of deep learning, the applications of deep learning-based data processing approaches in the SHM of many kinds of civil infrastructures, and the key challenges and future trends of the strategy of deep learning-based SHM.

• 정보보호학회논문지
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• 제31권6호
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• pp.1127-1136
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• 2021

전력 분석 공격에서 소비 전력 파형의 잡음과 정렬 불량은 공격 성공 여부를 좌우하는 주요한 요인이다. 따라서 이를 완화하기 위한 여러 연구가 수행되고 있으며 웨이블릿 변환 기반의 신호처리 방법도 그중 하나이다. 대부분의 웨이블릿을 사용한 연구에서는 파형 압축할 수 있는 이산 웨이블릿 변환을 사용해 왔는데, 그 이유는 연속 웨이블릿변환 기법이 선택된 스케일의 개수에 따라 데이터 크기 및 분석 시간이 증가할 뿐만 아니라 효율적인 스케일 선택 방법도 없기 때문이다. 본 논문에서는 전력 분석 공격에 최적화된 연속 웨이블릿 변환의 효율적인 스케일 선택 방법을 제안하며 이를 이용해 파형을 인코딩할 경우 분석 성능이 크게 향상될 수 있음을 보인다. 비프로파일링 공격인 CPA(Correlation Power Analysis) 및 DDLA(Differential Deep Learning Analysis) 공격 실험 결과, 제안하는 방법이 잡음 감쇄와 파형 정렬에 효과적임을 확인하였다.

• International journal of advanced smart convergence
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• 제8권3호
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• pp.69-77
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• 2019

Today, most of elevators have an emergency call facility for emergency situations. However, if the network installed in the elevator is also out of power, it cannot be used for the elevator remote monitoring and management. So, we develop an integrated and unified emergency call system, which can transmit not only telephone call but also data signals using PSTN(Public Switched Telephone Network) in order to remote monitoring and management of elevators, even though a power outage occurs. The proposed integrated emergency call system to process multiple data such as voice and operational information is a multi-channel board system which is composed of an emergency phone signal processing module and an operational information processing module in the control box of elevator. In addition, the RMS(remote management server) systems based on the Web consist of a dial-up server and a remote monitoring server where manages the elevator's operating information, status records, and operational faults received via the proposed integrated and unified emergency call system in real time. So even if there's a catastrophic emergency, the proposed RMS systems shall ensure and maintain the safety of passengers inside the elevator. Also, remote control of the elevator by this system should be more efficient and secure. In near future, all elevator emergency call system need to support multifunctional capabilities to transmit operational data as well as phone calls for the safety of passengers. In addition, for safer elevators, it is necessary to improve them more efficiently by combining them with high-tech technologies such as the Internet of Things and artificial intelligence.

• 정보보호학회논문지
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• 제30권6호
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• pp.1263-1270
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• 2020

차분 오류 공격은 암호화 장비에 인위적인 오작동을 유도하여 발생한 오류 암호문과 정상 암호문의 차분을 이용해 비밀키를 분석하는 기법이다. 일반적으로 차분 오류 공격은 암호 알고리즘의 중간값을 변조시켰을 때의 결과를 이용한다. 반면, 우리는 함수 전체를 생략시켰을 때의 결과를 이용하는 차분 오류 공격을 제안한다. 제안한 기법은 단일 오류 주입 암호문으로 수 초 이내에 전체 비밀키 복구가 가능한 매우 낮은 공격 복잡도를 갖는다. 또한, 우리는 오류가 함수 생략을 유도했는지 검증하는 방안을 제시함으로써 공격자 가정을 현실적으로 낮췄다. 제안한 기법을 실험적으로 검증하기 위해 Riscure 사의 Piñata 보드에 대한 오류 주입 공격을 수행한 결과 함수 생략으로 유도되지 않은 모든 오류 암호문을 거를 수 있었으며, 수 초 내에 비밀키 복구에 성공했다.

• 한국환경과학회지
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• 제30권12호
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• pp.1101-1111
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• 2021

In this study, among the W-S-R(Wiper-Signal-Rainfall) relationship methods used to produce sensor-based rain information in real time, we sought to produce actual rainfall information by applying machine learning techniques to account for the effects of wiper operation. To this end, we used the gradient descent and threshold map methods for pre-processing the cumulative value of the difference before and after wiper operation by utilizing four sensitive channels for optical sensors which collected rain sensor data produced by five rain conditions in indoor artificial rainfall experiments. These methods produced rainfall information by calculating the average value of the threshold according to the rainfall conditions and channels, creating a threshold map corresponding to the 4 (channel) × 5 (considering rainfall information) grid and applying Optima Rainfall Intensity among the big data processing techniques. To verify these proposed results, the application was evaluated by comparing rainfall observations.

• 한국지형학회지
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• 제18권4호
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• pp.203-212
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• 2011

감조하천이 발달한 경기도 파주시 탄현면 일대의 공릉천 감조구간을 연구지역으로 하여 표층퇴적물의 공간적 분포 특성을 조사하였다. 연구 결과는 다음과 같다. 첫째, 공릉천 감조구간의 표층퇴적물은 주로 실트로 구성되어 있다. 둘째, 종단축의 경우 겨울과 여름 모두 감조구간의 하류보다 상류에서 평균입도가 세립해지는 경향이 나타났으며, 여름이 겨울보다 평균입도가 작고 분급이 양호한 것으로 나타났다. 감조구간 종단축의 입도 분포를 볼 때 부유물질이 퇴적되는 데에는 조류의 작용, 특히 밀물의 영향을 많이 받는 것으로 보이며 이러한 경향은 겨울에 더 우세한 것으로 판단된다. 셋째, 횡단축의 경우 하도로부터 거리가 멀어질수록 평균입도가 세립해지는 경향이 나타났다. 넷째, 갑문과 같은 인공 시설 역시 유속을 정체시킴으로써 입도 분포에 영향을 미친다고 판단된다.

• 생태와환경
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• 제56권4호
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• pp.414-419
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• 2023

삼천포천은 제방을 따라 제내지에 인공구조물이 설치되어 있으며, 하상구조가 인간활동으로 교란되어 있다. 본 연구결과 부착조류와 저서성 무척추동물의 생물다양성이 여타 하천에 비해 낮은 것으로 나타났다. 따라서 생태하천 복원 시 제방의 제외지와 제내지를 동시에 친환경적으로 복원을 고려함으로써 생물다양성 증대를 도모하고 하상 복원 등을 통해 회유성 어류들이 하천생태계로 유입되어 생태계의 안정성 및 건강성을 회복해야 할 필요가 있다(Palmer et al., 2014). 이를 위해서는 생태하천 복원시 사용되는 재료는 무생물적 재료를 지양하고 과거부터 주로 서식하는 자생식물 등을 주재료로 사용하고 하도 구조는 하상의 현재 유로형상 (flow channel pattern)을 유지하도록 유도해야 한다. 유로 연장이 필요한 경우 직강화 등에 의해 축소되어서는 안되며 축소된 유로는 복원을 권장한다. 분절된 지류는 본류와 연결시키고 연력이 곤란한 웅덩이는 대상하천에 맞게 소택형 습지를 형성하도록 유도한다. 또한 생태통로(Eco-corridor) 확보 및 추이대 조성을 통해 생태환경 기능을 개선할 필요가 있으며 제내지의 폐천 부지는 하천구역으로 편입하여 생태습지 등으로 이용을 적극 고려해야 한다(Choi and Lee, 2019). 생태적 복원을 위해 주차장, 체육시설 및 공원 등은 배제해 자연성을 유지하되 주민의 활용도를 고려하는 것도 중요하다. 이를 통하여 삼천포천의 자연성 회복을 통한 생물다양성 증진 및 주민에게 다양한 문화 휴식 공간 제공 등의 생태계 서비스 능력을 향상을 기대한다(Bennett et al., 2009).