• Journal of Korean Society of Water and Wastewater
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• v.7 no.1
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• pp.29-36
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• 1993

The complex nature of low flow mixing in natural channels has been investigated using both laboratory experiments and the numerical solution of a proposed mathematical model that is based on a set of mass balance equations describing the mixing and mass exchange mechanisms. Laboratory experiments, which involved collection of channel geometry, hydraulic, and dye dispersion test data, were conducted in a model of four pool and riffle sequences in a 49-m long tilting flume. The experimental results show that flow over the model pool-riffle sequences is highly non-uniform. Concentration-time curves are significantly skewed with long tails. Comparison between measured and predicted concentration-time curves shows good agreement in the general shape, peak concentration and time to peak. The proposed model shows significant improvement over the conventional one-dimensional dispersion model in predicting natural mixing processes in open channels under low flow conditions through pools and riffles.

• Journal of Surface Science and Engineering
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• v.28 no.3
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• pp.123-132
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• 1995

While a nickel mesh and an expanded nickel sheet are used as current collectors for supporting active anode materials in rechargeable batteries, a porous nickel substrate is studied extensively for its 3-dimensional structure which has high capabilities for active materials and current collection. Optimum plating conditions were studied by polarization measurement. Scanning Electron Microscopy (SEM) showed that both electroless-and electro-plated nickel on an urethane substrate were highly porous and consisted of nearly spherical pores. The diameter and the channel size of the pores were found to be 300~500 $\mu\textrm{m}$ and 50~200$\mu\textrm{m}$, respectively. The shape of skeleton resembled a triangular prism with length extending about 50~100 $\mu\textrm{m}$.

• The Journal of Society for e-Business Studies
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• v.27 no.2
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• pp.205-218
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• 2022

Recently, digital transformation in manufacturing has been accelerating. It results in that the data collection technologies from the shop-floor is becoming important. These approaches focus primarily on obtaining specific manufacturing data using various sensors and communication technologies. In order to expand the channel of field data collection, this study proposes a method to automatically collect manufacturing data based on vision-based artificial intelligence. This is to analyze real-time image information with the object detection and tracking technologies and to obtain manufacturing data. The research team collects object motion information for each frame by applying YOLO (You Only Look Once) and DeepSORT as object detection and tracking algorithms. Thereafter, the motion information is converted into two pieces of manufacturing data (production performance and time) through post-processing. A dynamically moving factory model is created to obtain training data for deep learning. In addition, operating scenarios are proposed to reproduce the shop-floor situation in the real world. The operating scenario assumes a flow-shop consisting of six facilities. As a result of collecting manufacturing data according to the operating scenarios, the accuracy was 96.3%.

• Proceedings of the Korea Contents Association Conference
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• 2016.05a
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• pp.269-270
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• 2016

빅데이터 분석을 통한 여러 산업 군과 융합으로 시너지를 발생시키기 위해서, 다양한 유형의 데이터 수집을 통해 빅데이터를 구성하는 것이 첫 번째 단계이며 기상, 교통, 인터넷 활동, 상권 등의 다양한 출처로부터 데이터 연계를 수행하고 사물인터넷과 같은 실시간으로 발생하는 로그 성 데이터 수집을 고려한 실시간 처리 시스템을 설계 하였다. 이를 통해 서로 다른 유형의 데이터가 빅데이터로 수집 되면 여러 산업 군에서 요구되는 인사이트 기반의 빅데이터 분석을 통해 B2B 또는 B2C 서비스에 응용 될 수 있다.

• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.2
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• pp.11-18
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• 2021

A community-centered smart village process model was developed through the theoretical review of the rural field forum. By analyzing the difference in technology demand according to the digital capabilities of leaders by community type, village types were classified and detailed technologies were defined. The smart village process was proposed to enable residents to operate autonomously by inducing continuous interest and participation of local residents through the conception stage, planning stage, implementation and self-reliance stage, and allowing them to cooperate together. The business model canvas was reconstructed to be used in the workshop. It was applied to the village of Yesan-gun. As a result of running a resident workshop using the business model Cambus, the lack of resident awareness and illegal garbage dumping were presented as the first problems to be solved. The value of the village was set as 'a village that is clean and clean with a sense of residents, and a good place to live', and users were expressed as 'family' and 'outsiders'. It was suggested that we meet frequently to convey the value of the village by using broadcasting and announcements as a channel to convey the value. Core activities were to cultivate residents' consciousness, such as implementing a campaign against illegal garbage dumping, and to establish and guide separate collection sites. When a garbage collection center is installed, it was estimated that around 2 million won per month for management costs, and it was investigated that it was possible to spend an hour or so twice a month to solve the problem of illegal dumping. If a method to derive village projects based on the derived business model canvas is developed in the future, it will be more practical.

• Journal of Positioning, Navigation, and Timing
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• v.5 no.1
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• pp.11-20
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• 2016

In this paper, a system that can collect GPS L1 C/A, GLONASS G1, and BDS B1I signals with single front-end receiver was implemented using a universal software radio peripheral (USRP) and its performance was verified. To acquire the global navigation satellite system signals, hardware was configured using USRP, antenna, external low-noise amplifier, and external oscillator. In addition, a value of optimum local oscillator frequency was selected to sample signals from three systems with L1-band with a low sampling rate as much as possible. The comparison result of C/N0 between the signal collection system using the proposed method and commercial receiver using double front-end showed that the proposed system had 0.7 ~ 0.8dB higher than that of commercial receiver for GPS L1 C/A signals and 1 ~ 2 dB lower than that of commercial receiver for GLONASS G1 and BDS B1I. Through the above results, it was verified that signals collected using the three systems with a single USRP had no significant error with that of commercial receiver. In the future, it is expected that the proposed system will be combined with software-defined radio (SDR) and advanced to a receiver that has a re-configuration channel.

• Smart Structures and Systems
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• v.29 no.1
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• pp.181-193
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• 2022

Data-driven structural health monitoring (SHM) of civil infrastructure can be used to continuously assess the state of a structure, allowing preemptive safety measures to be carried out. Long-term monitoring of large-scale civil infrastructure often involves data-collection using a network of numerous sensors of various types. Malfunctioning sensors in the network are common, which can disrupt the condition assessment and even lead to false-negative indications of damage. The overwhelming size of the data collected renders manual approaches to ensure data quality intractable. The task of detecting and classifying an anomaly in the raw data is non-trivial. We propose an approach to automate this task, improving upon the previously developed technique of image-based pre-processing on one-dimensional (1D) data by enriching the features of the neural network input data with multiple channels. In particular, feature engineering is employed to convert the measured time histories into a 3-channel image comprised of (i) the time history, (ii) the spectrogram, and (iii) the probability density function representation of the signal. To demonstrate this approach, a CNN model is designed and trained on a dataset consisting of acceleration records of sensors installed on a long-span bridge, with the goal of fault detection and classification. The effect of imbalance in anomaly patterns observed is studied to better account for unseen test cases. The proposed framework achieves high overall accuracy and recall even when tested on an unseen dataset that is much larger than the samples used for training, offering a viable solution for implementation on full-scale structures where limited labeled-training data is available.

• The Research Journal of the Costume Culture
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• v.18 no.5
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• pp.789-808
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• 2010

The orientalism in fashion is believed to develop from the eclectic notion of oriental and occidental fashion. By studying on Gabrielle Chanel's clothing that is usually used by neutral colors and on Yohji Yamamoto's clothing that characterizes clothes in neutral colors, the purpose of this study is to seek ways for remaking Korean traditional clothing into a new modern one to gain a world reputation in terms of clothes. Therefore the study is for exploring the characteristics on the factors of fashion design such as color, line and textile materials with works of Gabrielle Chanel, a famous designer in Western world who has made a black color a popular one for people and works of Yohji Yamamoto, an well-known fashion designer of the East using neutral colors. This study analyzed, from the 2004 S/S to the 2006 F/W, the collection of works published in style.com through the works of Gabrielle Chanel, Yohji Yamamoto, and through the analysis of the visual target. A total of 527 images are used in this paper. Elements of fashion design analysis are lines, colors, and materials. The study reached the conclusion as follows after analyzing the characteristics on clothing with neutral colors of Gabrielle Chanel and Yohji Yamamoto. In case of aesthetic characteristics on the design of Gabrielle Channel, it has expression of feminist, sensual, modern and luxury. It is considered that Gabrielle Channel has a luxury image using a neutral color. Also using simple sleeveless in black and tweed structure, the garments have mixed with neutral colors. Fashion design characteristics on the design of Yohji Yamamoto classified into sensual, modern, ascetic expression. Therefore the design has a simple expression of using a black color. Yohji Yamamoto is a designer who pursues unstructured design by using various neutral colors such as black, gray and white based on the oriental sentiment.

• Analytical Science and Technology
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• v.35 no.2
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• pp.69-81
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• 2022

The method of measuring and classifying the energy category of neutrons directly using raw data acquired through a CZT detector is not satisfactory, in terms of accuracy and efficiency, because of its poor energy resolution and low measurement efficiency. Moreover, this method of measuring and analyzing the characteristics of low-energy or low-activity gamma-ray sources might be not accurate and efficient in the case of neutrons because of various factors, such as the noise of the CZT detector itself and the influence of environmental radiation. We have therefore developed an efficient method of analyzing radiation characteristics using a neutron and gamma-ray analysis algorithm for the rapid and clear identification of the type, energy, and radioactivity of gamma-ray sources as well as the detection and classification of the energy category (fast or thermal neutrons) of neutron sources, employing raw data acquired through a CZT detector. The neutron analysis algorithm is based on the fact that in the energy-spectrum channel of 558.6 keV emitted in the nuclear reaction ¹¹³Cd + ¹n → ¹¹⁴Cd + in the CZT detector, there is a notable difference in detection information between a CZT detector without a PE modulator and a CZT detector with a PE modulator, but there is no significant difference between the two detectors in other energy-spectrum channels. In addition, the gamma-ray analysis algorithm uses the difference in the detection information of the CZT detector between the unique characteristic energy-spectrum channel of a gamma-ray source and other channels. This efficient method of analyzing radiation characteristics is expected to be useful for the rapid radiation detection and accurate information collection on radiation sources, which are required to minimize radiation damage and manage accidents in national disaster situations, such as large-scale radioactivity leak accidents at nuclear power plants or nuclear material handling facilities.

• Solar Energy
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• v.17 no.2
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• pp.35-42
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• 1997

Thermal diode is a device which allows heat to be transferred in one direction by convection due to difference of density of fluid, and blocks heat flow in the opposite direction. Vertical plate for heat collection and radiation are of utility for design of thermal diode. It was considered the transient and steady state of air filled thermal diode with guide vane which combined rectangular and parallelogrammic shape enclosures. $Gr^*$ was kept constantly on $1.11{\times}10^{10}{\sim}1.4{\times}10^{10}$ and error range was ${\pm}3%$ during the experiment. Nu was examined when inclined angle are $15^{\cir\c}\;and\;45^{\circ}$ and, also the experiments was carried out with and without guide vane as well. Specially, Nu was linearly increased due to increase of $Gr^*$, and the effect of guide vane and dimensionless channel depth was sensitive. Developed state of temperature began at dimensionless time $0.5{\sim}0.6$ due to variation of inclined angle, which is characteristic of system.