• Smart Media Journal
• /
• v.11 no.4
• /
• pp.46-55
• /
• 2022

It is very important to first detect and remove defective fruits with scratches or bruised areas in the automatic fruit quality screening system. This paper proposes a method of detecting defective areas in fruits using the latest artificial intelligence technology, the Yolo V4 deep learning model in order to overcome the limitations of the method of detecting fruit's defective areas using the existing image processing techniques. In this study, a total of 2,400 defective fruits, including 1,000 defective apples and 1,400 defective fruits with scratch or decayed areas, were learned using the Yolo V4 deep learning model and experiments were conducted to detect defective areas. As a result of the performance test, the precision of apples is 0.80, recall is 0.76, IoU is 69.92% and mAP is 65.27%. The precision of pears is 0.86, recall is 0.81, IoU is 70.54% and mAP is 68.75%. The method proposed in this study can dramatically improve the performance of the existing automatic fruit quality screening system by accurately selecting fruits with defective areas in real time rather than using the existing image processing techniques.

• Journal of the Korean Society of Radiology
• /
• v.17 no.2
• /
• pp.175-184
• /
• 2023

Based on the actual shape of the detector and the data provided by the manufacturer, the shape of the detector was implemented through Penelope simulation and applied to the appropriate four-layer thickness based on the efficiency obtained from the measurements. Efficiency calculations to determine the effect of the simulated number of Full Energy Peak Efficiency(FEPE) channels in the detector and the outside contact layer in the crystal on the Full Energy Peak Efficiency were performed for various four-layer thicknesses of 0.3, 0.5, 0.7, 1.0, 1.2, and 1.4 mm using the Penelope Code. When the thickness of the external contact layer was increased by 5 times, the Full Energy Peak Efficiency decreased by about 36% for 59.50 keV, and the Full Energy Peak Efficiency decreased by 10% for 1836. In addition, as it increased by 10 times, the Full Energy Peak Efficiency decreased by about 20% for 59.54 keV, and 7% for 1836.01 keV. The Penelope simulated Full Energy Peak Efficiency channel decreases exponentially with the increase in the four layers. In addition, it was confirmed that the total effect curve was well matched with a relative difference of less than 3.5% in the 0.3-1.4 mm dead layer thickness region. However, it was found that the inhomogeneous dead layer is still a parameter in the Monte Carlo model.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.38C no.3
• /
• pp.227-232
• /
• 2013

Due to the development of ITS technology, various services related to transportation under vehicular environments have been provided. Especially, as wireless communication technology, WAVE has been established as a standard for vehicle-to-vehicle communications. WAVE has fast connection and excellent mobility characteristics. A VSC-A project is conducting by global automotive OEMs in USDOT. This project introduces the advanced safety services with vehicle-to-vehicle communications. In this paper, we presented the scenario of a do not pass warning service, which prevents an accident during overtaking activity by using vehicle-to-vehicle communications. In addition, we analyzed network performance under WAVE. In conclusion, we introduced the simulation results. Finally, we summarized the communication range and delay values for consideration factors for a overtaking model.

• Journal of Navigation and Port Research
• /
• v.37 no.1
• /
• pp.41-48
• /
• 2013

A positioning technique using the augmentation system has been researched to improve the accuracy. The network RTK is the precise positioning technique using carrier phase correction data from reference stations and is constantly being researched. The study for the system accuracy has been performed but system integrity research has not been done as much as system accuracy. In this paper, we presented the anomaly detection algorithm by satellite system and the diagnosis algorithm to a basic research in the integrity on network RTK. And the presented algorithms are verified on the DL-V3 dual-frequency receiver and the simulated error scenario using the GSS7700.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.38 no.7
• /
• pp.589-594
• /
• 2014

Recently, higher capacity and energy density of lithium ion batteries are increasingly demanded for enhancing their performance in view of the rise in the commercial distribution of electric and hybrid vehicles. Computational analysis of a porous structure of vanadium pentoxide cathode was performed, employing a phase field model. The incipient model was designed as a spherical structure with cylindrical-shaped pores. Modifying the diameters and lengths of the pore cylinder and the number of pores, we considered different conditions for the porous vanadium pentoxide cathodes for analyzing their effect on the amount of lithium ion intercalated to them. Subsequently, we optimized the porous structure to contain the largest amount of intercalated lithium ion during discharge.

• Applied Chemistry for Engineering
• /
• v.2 no.4
• /
• pp.385-392
• /
• 1991

Nonstoichiometry and defect model for $Ni_{1-x}O$ were determined by coulometric titration method. In the temperature range of 1123-1198K and oxygen partial pressure of 0.21-0.1 atm, the nonstoichiometry was found to be proportional to the fourth root of the oxygen partial pressure. This pressure dependence can be explained by the fact that nonstoichiometric $Ni_{1-x}O$ contains singly ionized metal vacancies as the predominant point defects. At T=1173K and $Po_2=0.21atm$, the nonstoichiometry, x was $1.21{\times}10^{-4}$. The standard formation enthalpy of defects in $Ni_{1-x}O$ was found, on the basis of this defect model, to be 0.95 eV. Also the result indicates that both of singly and doubly ionized metal vacancies are simultaneously present at above 1248K.

• Solar Energy
• /
• v.13 no.2_3
• /
• pp.120-132
• /
• 1993

The purpose of this research is to study the characteristics of heat transfer in composite rotary heat pipe as modeled turbine rotating by a finite element analysis and experiment. Nu number, Re number, Pr number and dimensionless condensate layer thickness by thermal input and revolutions per minute were given as analysis factors. The comparison between calculated and experimental data showed similar tendency. Therefore the analysis method may be useful to predict the performance of composite heat pipe. The resistance on heat pipe showed the best effect of heat transfer by film condensation, by decreasing film condensation, the heat transfer rate from condenser was increased rapidly. The dimensionless condensate layer thickness according to Re number at given Pr number showed constant values, the dimensionless condensate layer thickness is proportionate to the square root of inverse of revolution number per minute. In this study Nu=A$({\delta}({\omega}/v)^{-1/2}Re^B)$ is used to the convection heat transfer coefficient and A=0.963, B=0.5025 were obtained as analysis predicts.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1996.04a
• /
• pp.199-199
• /
• 1996

급성 간질환모델에 대한 인진호 추출분획의 간장 약효검색, 방법 1. $CCl_4$ 간장해 : SD계 수컷 흰쥐에 $CCl_4$와 olive oil 혼합액(1:4v/v%)을 체중100g당 0.2$m\ell$씩 복강내 투여하였으며, 시험약물은 $CCl_4$ 혼합액 투여 4시간전 및 6시간후에 경구로 2회 투여하였다. 48시간후에 부검하여 혈청을 얻어 간기능검사 항목인 ALT 및 AST 활성을 측정하였다. 2. D-Galactosamine 간염 : SD계 수컷 흰쥐에 D-GalactosamineㆍHCl을 650mg/kg씩 복강내 투여하였으며, 시험약물은 $CCl_4$ 간장해시험과 동일하게 2회 경구투여하였다. D-Galactosamine 투여 24시간 후에 부검하여 혈청을 얻어 간기능검사 항목인 ALT 및 AST 활성을 측정하였다. 3. 담즙울체모델 : SD계 수컷 흰쥐에 ANIT 100mg을 olive oil 1$m\ell$에 현탁시켜 80$m\ell$/kg b.wt. 용량으로 1회 경구투여하였으며, 시험약물은 ANIT 투여전 2시간, 투여 후 6, 22, 28시간 간격으로 4회 경구투여하였다. ANIT 투여 47시간 후에 1시간 동안 담즙을 채취하였고, ANIT 투여 48시간째 채혈하여 혈청내 총빌리루빈치를 측정하였으며 담즙배출량, 담즙중 담즙산량도 측정하였다. 4. 약물투여 음성대조 : 1% CMC-Na 용액(10$m\ell$/kg b.wt.) 양성대조 : Silymarin(25mg/kg), UDCA(25mg/kg), DDB(37.5mg/kg) 인진호추출분획 : 인진호 원료의 수침액인 BE분획의 수득률을 기준으로 하여, KP(180mg/kg), PS-1 및 PS-2(300mg/kg), EE(500mg/kg), HH(640mg/kg), BE(1500mg/kg)

• The Journal of the Korea institute of electronic communication sciences
• /
• v.11 no.12
• /
• pp.1165-1174
• /
• 2016

The energy band gaps and the bowing parameters of zincblende InAs1-xN are determined by using an empirical pseudopotential method(EPM) within the improved virtual crystal approximation(VCA), which includes the disorder effect. The direct-band-gap bowing parameter calculated by using the EPM is 4.1eV for InAs1-xNx ($0{\leq}x{\leq}0.05$). The dependences of the band gaps of N-dilute InAs1-xNx on the temperature and composition are calculated by modifying the band anti-crossing(BAC) model. The calculation results are consistent with experimental values, and the coupling parameter CMN of InAs1-xNx is found to be equal to 1.8 by fitting the EPM data.

• The Transactions of the Korea Information Processing Society
• /
• v.7 no.9
• /
• pp.2797-2806
• /
• 2000

Recently, DDSs(Distributed Database Systems) have been implemented on V AN(V alue Added Network) as we know the amazing expansion of information network. DDS can yield significant cost and response time advantages over centralized systems for geographically distributed organizations. However, inappropriate design can result in high cost and poor response time to maintain the database at each site. In a DDS design, the main problem is how to select proper computer and how to allocate data fragment into a proper site. In this paper, we address DDS design problem of selecting the proper class of computers and the allocating data files on VAN. Also, the formulated model includes two objectives, the waited response time and the investment cost to include their relationship. Specially, the formulation of waited response time is based on M/M/1 queueing system to evaluate more precisely. GA(Genetic Algorithm), a kind of heuristic search method, is developed to search an optimal solution in the proposed design model and we show the simulation result to examine the algorithm performance.