• Journal of IKEEE
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• v.23 no.3
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• pp.1092-1095
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• 2019

In this paper, we propose the development of an embedded board for construction of smart factory. The proposed embedded board for construction of smart factory consists of main module, ADC module, I/O module. Main module is a main calculating device which includes communication pard that allows interface with external device with using industrial protocol and is ported operating system makes board operating into. ADC module takes part in transferring digital signal has converted from electrical signal to the main module from the external sensor which is installed on the field. I/O module is an input and output module which transfers to the main module about a status, alarm, command signal of field device and it has a function that blocks external noises from field device with isolation circuit into it. In order to evaluate the performance of the proposed embedded board for construction of smart factory, it has been tested by an authorized testing institute. As a result, quantity of interacting protocol was 5, speed of hardware clock synchronization was under 10us and operating time of battery without source power was over 8 hours. It produced the same result as the world's highest level.

• The Journal of the Convergence on Culture Technology
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• v.7 no.1
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• pp.646-653
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• 2021

The medical bed developed in this study consists of N keys and each is driven vertically by an actuator. Since M sensors are mounted on each keyboard to measure body pressure, the resolution of the body pressure map is determined by the MN. A sensor controller is mounted on each keyboard, and the body pressure values measured from M sensors are transmitted to the main controller through a serial communication network such as CAN (Car Area Network). Each keyboard is equipped with a servo driver that drives a motor, and it is connected to the main controller via CAN to control the height of the keyboard according to the displacement value indicated by the main controller. In addition, the maximum body pressure value and body pressure ratio applied to each part of the keyboard are calculated and used as the basic data for controlling bed comfort by artificial intelligence. As a result, the proposed system can be a foundation that can be used for the control of body comfort and pressure sore prevention by artificial intelligence to be developed in the future.

• Proceedings of the IEEK Conference
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• 2000.09a
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• pp.247-250
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• 2000

본 논문에서는 MPEG-2 AAC 오디오 복호화 시스템을 효율적으로 설계하고 구현하였다. 구현된 시스템은 2채널의 메인 프로필 MPEG-2 AAC 비트열을 실시간으로 복호화하고, 32, 44.1, 48kHz의 표본화 주파수를 지원하여, 표준안에서 제안하는 툴 중 커플링 채널을 제외한 모든 툴을 지원한다. 설계된 시스템은 허프만 복호화와 예측 과정을 수행하는 두개의 독립된 모듈과 Programmable DSP 코어의 혼합 구조(hybrid architecture)로 최적화된 구조를 갖는다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.04a
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• pp.232-236
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• 1992

컴퓨터로부터 디자인된 부품을 CMM(Coordinate Measuring Machine)과 연결함으로서 측정 의 자동화를 이룰수 있다. 또한, 기존의 여러 CAD시스템들은 모델의 형상오차와같은 정보는 지원하지 않기 때문에 측정의 자동화의 기능은 완전한 모델 디자인을 통한 CAD 시스템의 지원 으로 확장될수 있다. 여기에서는 금형의 부품중에서 메인플레이트(Main Plate)와 핀 및 부시 류(Pins and Bushings)를 다루며, 이들의 형상오차(From Tolerance)와 오리엔테이션 오차( Orientation Tolenrance)를 중심으로 한국공업규격에 근거하여 측정 및 분석이 이루어진다.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.2
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• pp.267-275
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• 2012

In this study, normal wind load and blast wind load are modeled mathematical. And the periodical torque and bending moments transmitted to the main shaft of wind turbine are investigated. A normal wind model assumed, of which the wind velocity is increased according to the height from ground. The average values and the harmonic terms of the transmitted moments are studied on the wind direction of range $-45^{\circ}{\sim}45^{\circ}$ and the bending moment characteristics are examined, which is regarded as the main source of the misalignment of gear train. In normal wind load case, excitation frequency is 3X (X : Rotor speed). When the wind direction is $+22.5^{\circ}$, the horizontal axis of bending moment occur the 50% of main torque. This result leads to edge contact of gear teeth by shaft elastic deformation. In blast wind load case, excitation frequency are 3X,6X,9X. Additional, in the (+) direction of wind load, relative harmonic percentage is increase.

• Horticultural Science & Technology
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• v.34 no.1
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• pp.77-83
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• 2016

The measurement of total fresh weight of plants provides an essential indicator of crop growth for monitoring production. To measure fresh weight without damaging the vegetation, image-based methods have been developed, but they have limitations. In addition, the total plant fresh weight is difficult to measure directly in hydroponic cultivation systems because of the amount of nutrient solution. This study aimed to develop a real-time, precise method to measure the total fresh weight of Romaine lettuce (Lactuca sativa L. cv. Asia Heuk Romaine) with growth stage in a plant factory using a nutrient film technique. The total weight of the channel, amount of residual nutrient solution in the channel, and fresh shoot and root weights of the plants were measured every 7 days after transplanting. The initial weight of the channel during nutrient solution supply (Wi) and its weight change per second just after the nutrient solution supply stopped were also measured. When no more draining occurred, the final weight of the channel (Ws) and the amount of residual nutrient solution in the channel were measured. The time constant (${\tau}$) was calculated by considering the transient values of Wi and Ws. The relationship of Wi, Ws, ${\tau}$, and fresh weight was quantitatively analyzed. After the nutrient solution supply stopped, the change in the channel weight exponentially decreased. The nutrient solution in the channel slowly drained as the root weight in the channel increased. Large differences were observed between the actual fresh weight of the plant and the predicted value because the channel included residual nutrient solution. These differences were difficult to predict with growth stage but a model with the time constant showed the highest accuracy. The real-time fresh weight could be calculated from Wi, Ws, and ${\tau}$ with growth stage.

• Journal of Food Hygiene and Safety
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• v.36 no.6
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• pp.481-487
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• 2021

The purpose of this study was to provide safety management information by analyzing the survival and growth-related properties of foodborne pathogens from Romaine lettuce. After cultivating E. coli O157:H7 for 72 h on Romain lettuce via spray inoculation, the bacteria population increased by 2.0 log CFU/g from the initial population, confirming the possibility of survival and multiplication of the pathogen thereon. The study also revealed that there is no significant difference in the cultivation of E.coli O157:H7 after 72 h from inoculation on damaged and undamaged lettuce leaves. As a result of investigating distribution of E.coli O157:H7 on damaged lettuce leaves, it was found that the bacteria is unlikely to adhere on the smooth surface of undamaged leaves and, thus, results in a low population density, whereas the bacteria cluster on the rough surface of damaged leaves and easily enter through the damaged tissues. Furthermore, after 24 h of cultivation of the pathogenic microbe in the extract with concentrations of 10-100%, utilization of the lettuce extract by the pathogen was found to be 8.9 log CFU/mL E. coli O157:H7, 8.6 log CFU/mL L. monocytogenes, and 8.8 log CFU/mL P. carotovorum. The increase in the population of both the pathogenic microbe and foodborne pathogen reached over 4 log CFU/mL, implying the microbe can utilize the lettuce extract as a source of nutrition. Compared to the initial inoculation concentration in 0.1% lettuce extract, the final concentration has increased up to 2.7 log CFU/mL E. coli O157:H7, 1.3 log CFU/mL L. monocytogenes, and 2.9 log CFU/mL P. carotovorum. Accordingly, the study confirms that the minimal growth concentration of the pathogenic microbe is lower than 0.1% and that the pathogen possibly survive and multiply inside the lettuce leaves given the lettuce extract with concentration of 0.1% is consistently supplied through the damaged tissues.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.33 no.5
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• pp.437-442
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• 2015

Recently, the size of point cloud is increasing rapidly with the high advancement of 3D terrestrial laser scanners. The study aimed for improving a file-referring octree, introduced in the preceding study, which had been intended to generate an octree and to query points from a large point cloud, gathered by 3D terrestrial laser scanners. To the end, every leaf node of the octree was designed to store only one file-pointer of its first point. Also, the point cloud file was re-constructed to store points sequentially, which belongs to a same leaf node. An octree was generated from a point cloud, composed of about 300 million points, while time was measured during querying proximate points within a given distance with series of points. Consequently, the present method performed better than the preceding one from every aspect of generating, storing and restoring octree, so as querying points and memorizing usage. In fact, the query speed increased by 2 times, and the memory efficiency by 4 times. Therefore, this method has explicitly improved from the preceding one. It also can be concluded in that an octree can be generated, as points can be queried from a huge point cloud, of which larger than the main memory.

• Journal of Broadcast Engineering
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• v.9 no.3
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• pp.236-245
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• 2004

A multiview sequence CODEC with view scaiability is proposed in this paper. We define a GGOP (Group of GOP) structure as a basic coding unit to efficiently code multiview sequences. 7he proposed CODEC provides flexible GGOP structures based on the number of views and baseline distances among cameras. Multiview sequences encode consists of disparity estimation/compensation, motion estimation/compensation, residual coding and rate control and generates multiview sequence bitstream. The main bitstream is the same as an MPEG-2 mono-sequence bitstream for MPEG-2 compatibility. The auxiliary bitstream contains information concerning the remaining multiview sequences except for the reference sequences. The proposed CODEC with view scalability provides that a number of view flints are selectively determined at the receiver according to the type of display modes. The proposed multiview sequence CODEC is tested with several multiview sequences to determine its flexibility. compatibility with MPEG-2 and view scaiability. In addition, we subjectively confirm that the decoded bitstreams with view scaiability can be Properly displayed by several types of display modes. including 3D monitors.

• Science of Emotion and Sensibility
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• v.17 no.4
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• pp.19-28
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• 2014

The number of people using on-line shopping has rapidly increased over time. In particular, open-market is the most potential on-line market. Since there are too many products in open-market, customers have serious troubles finding products they want. Thus, interface should be improved so that open-market is able to offer products they want effectively. This study analyzed web interface based on main web pages of four major open-market companies in Korea, and performed satisfaction evaluation according to the analyzed factors. As a result, it reveals that what kind of factors the customers prefer and there is a causal relation between the most satisfactory open-market and the preferred factors of the customers.