• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.6B
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• pp.1113-1122
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• 1999

In this paper, we propose MSS(Multicast Synchronization Server) and QCS(QoS Conversion Server) models that can support IP multicast and QoS(Quality of Service) over the ATM network more efficiently. In the MSS model, it is possible to establish shortcut VCs(Virtual Circuits) among all hosts in the ATM network and to transfer multicast data at high speed. Also the MSS model is more scalable, because the number of inter-cluster VCs needed in the MSS model is less than that of EARTH. In the QCS model, ATM switch is modified to support one QoS service and best effort service through the one point-to-multipoint VC at the same time so required network resources are reduced, and dedicated server is used for QoS conversion to accept heterogeneous receivers more efficiently. In this Paper, the proposed MSS model and QCS model have solved both efficiency problem and scalability problem. It is proved through the comparison of the VCs required in each model.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.12
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• pp.1119-1125
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• 2010

Most of the sludge pre-treatment methods to improve the anaerobic digestibility of sludge are not practied in the fields with low economical efficiency. The venturi cavitation system (VCS) adopting hydrodynamic cavitation is simple and requires low energy. This research was conducted to investigate the optimum design and operating conditions of the VCS. The experimental results indicated that the optimum number of venturi in series was three, and the suction mode operation of the pump yielded 1.6 times higher pre-treatment efficiency per unit energy consumption than the discharge mode. The combination of venturies with different throat sizes did not affect the pre-treatment efficiency. Also, the parallel installation of the three in series venture unit yielded 30% higher pre-treatment efficiency per unit energy consumption than the single unit. Under parallel conditions, the solubilization efficiency was 5.6 mg ${\Delta}SCOD/g$ TS/kWh, which is higher than the previously reported value.

• The KIPS Transactions:PartC
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• v.10C no.1
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• pp.45-50
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• 2003

Guaranteed Frame Rate (GFR) service category is one of the most recent ATM service categories. The GFR specification was recently finalized by the ATM Forum and is expected to become an important service category which can efficiently support TCP/IP traffic in ATM network. In GFR switch implementation, it is important to guarantee MCR (minimum cell rate) and improve fairness. In this paper, we propose a new scheduling algorithm for the GFR service. Proposed algorithm provides priority to VC (virtual circuit)s and high Priority given to a VC which has fewer untagged cells in buffer. High priority VCs are serviced before low priority VCs. Proposed algorithm can guarantee MCR and improve fair sharing of the remaining bandwidth between GFR VCs. From computer simulation results, we demonstrate the proposed scheduling algorithm provide much better performance in TCP goodput and fairness than previous schemes.

• Journal of Internet Computing and Services
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• v.23 no.4
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• pp.1-9
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• 2022

Recently, the functions of smart speakers have diversified, and the penetration rate of smart speakers is increasing. As it becomes more widespread, various techniques have been proposed to cause anomalous behavior against smart speakers. Dolphin Attack, which causes anomalous behavior against the Voice Controllable System (VCS) during various attacks, is a representative method. With this method, a third party controls VCS using ultrasonic band (f>20kHz) without the user's recognition. However, since the method uses the ultrasonic band, it is necessary to install an ultrasonic speaker or an ultrasonic dedicated device which is capable of outputting an ultrasonic signal. In this paper, a smart speaker is controlled by generating an audio signal modulated at a frequency (18 to 20) which is difficult for a person to hear although it is in the human audible frequency band without installing an additional device, that is, an ultrasonic device. As a result with the method proposed in this paper, while humans could not recognize voice commands even in the audible band, it was possible to control the smart speaker with a probability of 82 to 96%.

• Food Science of Animal Resources
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• v.38 no.5
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• pp.1109-1119
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• 2018

In this paper, we report the development of a nondestructive prediction model for lean meat percentage (LMP) in Korean pig carcasses and in the major cuts using a machine vision technique. A popular vision system in the meat industry, the VCS2000 was installed in a modern Korean slaughterhouse, and the images of half carcasses were captured using three cameras from 175 selected pork carcasses (86 castrated males and 89 females). The imaged carcasses were divided into calibration (n=135) and validation (n=39) sets and a multilinear regression (MLR) analysis was utilized to develop the prediction equation from the calibration set. The efficiency of the prediction equation was then evaluated by an independent validation set. We found that the prediction equation - developed to estimate LMP in whole carcasses based on six variables - was characterized by a coefficient of determination ($R^2_v$) value of 0.77 (root-mean square error [RMSEV] of 2.12%). In addition, the predicted LMP values for the major cuts: ham, belly, and shoulder exhibited $R^2_v$ values${\geq}0.8$ (0.73 for loin parts) with low RMSEV values. However, lower accuracy ($R^2_v=0.67$) was achieved for tenderloin cuts. These results indicate that the LMP in Korean pig carcasses and major cuts can be predicted successfully using the VCS2000-based prediction equation developed here. The ultimate advantages of this technique are compatibility and speed, as the VCS2000 imaging system can be installed in any slaughterhouse with minor modifications to facilitate the on-line and real-time prediction of LMP in pig carcasses.

• Publications of The Korean Astronomical Society
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• v.27 no.5
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• pp.419-429
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• 2012

In this paper, we propose a new re-quantization method after FFT processing to prevent the distortion of correlation result of VCS (VLBI Correlation Subsystem). The re-quantization is used to rearrange the data bit so as to reduce the data rate processed as 16-bit of FFT result of VCS. Having done this procedure, we found that the distorted spectrum of correlation result occurred in the delay tracking experiments by the re-quantization method introduced for initial design of VCS. In order to solve this, two kinds of re-quantization method, that is, the comparison and selection-type, are proposed. The first is to re-quantize the FFT result as a valid-bit by comparing with the input data after determining the adequate threshold. The second is manually to select the valid-bit of FFT result after finding the valid-field of data according to the bit-distribution of input data. We confirmed that the second is more effective compared with the first through the experimental result, and it will be implemented without so much modification of applied method in the condition of the limited resource of FPGA. The re-quantization is, however, carried out with 4-bit in the proposed second method for FFT result, and then the distortion of correlation result is also appeared. To fix this problem, the bit for re-quantization is extended to 8-bit. The proposed 8-bit selection-type is effectively verified so that the distortion of correlation result disappeared by applying to VCS in consequence of the simulation and correlation experiments.

• Journal of the Korean Society of Radiology
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• v.16 no.2
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• pp.177-184
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• 2022

The purpose of this study is surveyed diagnostic radiography (DR) examination in veterinary hospital (VC) including non-ionization radiation such as ultra-sonography and magnetic resonance imaging. From June 1 to June 20. 2021, we surveyed the VC in 00 metropolitan city by using a structural questionnaire which are location of VC and X-ray unit et al.. Data are expressed as a mean with standard deviation for continuous variable or percent for categorical variable using SPSS ver. 26.0. As the first animal to be visited, dogs were the highest with 61.9%, followed by cats with 12.9%. In 87.1% fo cases, DR units were used, and 4 VCs did not. In 27 VCs using DR units, 48.1% separated examination room and control room, 19.8% examined in animal visited, protective clothing was in all VCs, 55.6% were measured radiation exposure dose, 92.6% was responded a necessary for examination education. From the above results, it will help to revise the guidelines for DR units and examination in korea VCs.

• Journal of Technology Innovation
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• v.24 no.3
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• pp.1-28
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• 2016

This paper suggests objective practical investment index for venture capital investment evaluation, deviating from investment behavior that relies on venture capitalist's intuition and experience. To deduct universally valid practical venture investment index, We conducted a survey of venture capitalist 65 and analyzed the data using AHP method. The results show that when VCs determine whether to invest in a venture or not, market related factors are considered most important. For venture companies who hope to receive investment from VCs, market access, CEO's technical / managerial experience, and recommendation/reputation are considered as crucial factors.

• Journal of the Institute of Convergence Signal Processing
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• v.14 no.4
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• pp.261-269
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• 2013

This paper describes the design and development of VSI (VLBI standard interface) optical adapter for transmitting VLBI(Very long baseline interferometry) observation data with optical signal. VSI cable comprised of 80-line is being used for observed data transmission with maximum length of 5-meter between playbacks (Mark5B, VERA2000) and raw VLBI data buffer (RVDB), RVDB and VLBI correlation subsystem (VCS) in Daejeon correlator. It has a plan to conduct the data processing for 16-stations and introduce the 14 RVDB systems in near future. And data loss frequently occurred because of trouble of VSI cable MDR80 connector. By considering the data loss by connector error of VSI cable, RVDB system extension plan, effective space usage and long distance data transmission(e-VLBI), the VSI optical adapter was proposed and developed for effectively transmitting and receiving VLBI data through optical signal. In order to confirming the performance of developed VSI optical adapter, the experiments for data transmission was conducted between playback and RVDB system, and confirmed that data transmission was clearly done without any data loss.

• The Korean Journal of Food And Nutrition
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• v.20 no.1
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• pp.9-13
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• 2007

In this study, sesame oils and sesame meals(A, B) were obtained from roasted sesame at $200^{\circ}C$ and $220^{\circ}C$, respectively. The total volatile component(VC) contents of these samples(A, B) were as follows : The sesame oils had 1,397.1 ppm and 1,518.8 ppm, and the sesame meals had 663.2 ppm and 775.3 ppm for samples A and B, respectively : sesame flavor was16,507.9 ppm, The major VCs in the sesame oils were pentane, 2-butanone, pyrazine, methylpyrazine, 2,5- and 2,6-dimethyl pyrazine, furfuryl alcohol, guaiacol and 4-vinylguaiacol. The pyrazine contents of the seasame oils were 834.4 ppm and 816.4 ppm for samples A and B, respectively. The major VCs in the sesame meals were 2-butanone, hexanal, pyrazine, methyl pyrazine, 2,6-dimethyl pyrazine, furfuryl alcohol, and so forth. For artificial sesame flavor, the total VC content was 16,507.9 ppm, and the major VCs were 2-butanone, guaiacol, and 4-vinylguaiacol. Approximately 35.02% of the total VC content of sesame flavor was composed of 2-butanone, guaiacol, and 4-vinylguaiacol, and these constituted more than 1,000 ppm of its total VC content.