• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.10
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• pp.2935-2944
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• 2009

This paper proposes Dual DBR(Drum-Buffer-Rope) system for a small-to-medium-sized PCB(Printed Circuit Board) manufacturing line. DBR method of TOC(Theory of Constraints) is an effective system for a small-to-medium-sized company to build production scheduling system. But to apply it to PCB line, it needs more technical consideration because of multiple constraints, looping process line and complex buffer management. This paper proposes an answer of these problems using Dual DBR to build production scheduling system more successfully. And it was confirmed that lead time was reduced more than 20% applying Dual DBR system to a domestic PCB manufacturing line actually.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.17-18
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• 2007

Solid oxide fuel cells are clean, pollution-free technology for the electrochemical generation of electricity at high efficiency. Specially, the polarization resistance between electrolyte and electrode of SOFC unit cell is of importance, because it is desirable to develop SOFC operating at intermediate temperature below $800^{\circ}C$. The LSCF cathode prepared using modified oxalate method was investigated with different electrolyte. A precursor was prepared with oxalic acid, ethanol and $NH_4OH$ solution. The LSCF precursor was prepared at $80^{\circ}C$, and pH control was 2, 6, 8, 9 and 10. The precursor powder was calcined at $800^{\circ}C$, $1000^{\circ}C$ and $1200^{\circ}C$ for 4hrs. The crystal of LSCF powders show single phase at pH 2, 6, 8 and 9, and the average particle size was about $3{\mu}m$. The LSCF cathode with heat treatment at $1200^{\circ}C$ showed a plot of electric conductivity versus temperature. Unit cell prepared from the LSCF cathode, buffer layer between cathode and electrolyte and the LSGM, YSZ, ScSZ and CeSZ electrolyte. Also interface reaction between LSCF, buffer layer and electrolyte were measured by EPMA and the polarization resistance for unit cell with cycle measure using a Solatron 1260 analyzer.

• Journal of Veterinary Clinics
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• v.22 no.3
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• pp.228-232
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• 2005

Damaged spermatozoa are supposed to be trapped in glass wool. In the respect of this, two glass wool filtration spermatozoa groups (0.5 cm, 1 cm depth) were compared with control group to assay sperm motility, HOS values, and vital rate by CFDA/PI staining method following glass wool filtration. The motility of canine sperm extended with PBS+PVP after glass wool filtration was lower in both filtrated groups than that of the control group (p<0.01) and the same significant difference was also shown in canine semen extended with Tris buffer (p<0.01). The motility of canine sperm diluted with PBS+PVP was higher than that diluted with Tris buffer in the same experimental groups (p<0.05). The motility of control group was not significantly decreased until 2 hours immediately after extending, however, the motility of both glass wool filtrated spermatozoa were significantly decreased as time passed until 2 hours after filtration (p<0.01). At each time for assay (immediately, 30 min, 2 hours after filtration), the motility of canine sperm of control group was higher than the filtrated groups (p<0.05), whereas the motility of 0.5 cm depth group was higher than 1 cm depth group at the immediate time after filtration (p<0.05), 30 minutes later (p<0.05) with no difference at 2 hours. No difference was shown among the experimental groups in HOS values of canine sperm after glass wool filtration. The vital rate assayed by CFDA/PI staining of both filter groups was higher than the control group (p<0.05).

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.8
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• pp.7-13
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• 2002

In this paper, we propose an traffic control algorithm for efficient link utilization of ATM-ABR service based on fuzzy logic. The proposed algorithm, controls transmission rates of source according to switch buffer size and input cell tate by using the fuzzy rate . For this method we developed a model and algorithm of fuzzy traffic control method and fuzzy traffic controller which based on ER of VS/VD. For the fuzzy traffic controller, we also designed a membership function, fuzzy control rules, and a max-min inferencing method.

• Journal of the Korean Vacuum Society
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• v.6 no.S1
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• pp.166-171
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• 1997

IBED is a very promosing thin film deposition method because of its many advantages, such as excellent adhesion property of films to substrates, room temperature processing, ease of control over the composition and thickness of films, and so on, over the conventional techniques, It has been widely applied in the field of surface modification of materials in the last decade. In our laboratory, many kinds of thin films, such as wear-resistant hard coatings, corrosion and oxidation protective coatings, biomaterial films, buffer layer for high temperature superconductor films, and oxygen sensitive film, have been synthesized by IBED, and several industrial applications of the IBED films have been conducted.

• Journal of the Korean Society of Safety
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• v.12 no.3
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• pp.60-66
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• 1997

In this paper, a moving object surveillance system, which can extract moving object in real-time, using image subtraction method is described. This technique based on the novelty filter having the structure of neural network associative memory. Digital arithmetic and timing control parts were composed of hardwired controller to treat two-dimensional massive image information. SRAMS having 20 ns access time were used for the image buffer that has high speed write/read property. Image extraction algorithm is discussed and supported by simulation and experiments.

• Journal of the Korean Operations Research and Management Science Society
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• v.22 no.2
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• pp.45-65
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• 1997

We build a queueing model for buffered leaky bucket system. First, we set up system equations and them calculate the steady-state probabilities at an arbitrary time epoch by recursive method. We derive the mean waiting time and the mean number of cells in the input buffer, and evaluate the performance of the buffered leaky bucket system to find the optimal queue capacity and token generation rate that meet the quality of service(QoS).

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.845-848
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• 2003

We investigated a field emission property of CNTs grown on pre-treated substrates by $H_{2}$ plasma etching method in vacuum chamber (<${10^{-7}}$ Torr). To improve the emission characteristics, various catalysts and buffer layers were used. The morphology and density of catalyst layer was controlled by the different plasma pre-treatment conditions, resulting in the control of the growth characteristics of CNTs.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.14 no.24
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• pp.97-103
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• 1991

This paper deals with a scheduling problem with the objective of maximizing the throughput rate in flexible manufacturing system with shop type. Manufacturing system is consisted of multi-stage in series. All kinds of parts are processed in same in processing time. No buffer space is allowed between stages, and no part waiting is allowed in each stage. Part flow control method for determining the optimal production sequence of all parts and the production starting time of each part is proposed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.6
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• pp.1148-1159
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• 1997

In the broadband integrated service digital networks (B-ISDN), ATM switches hould be abld to accommodate diverse types of applications ith different traffic characteristics and quality ddo services (QOS). Thus, in order to increase the utilization of switches and satisfy the QOS's of each traffic type, some types of priority control schemes are needed in ATM switches. In this paper, a nonblocking input and output queueing ATm switch with capacity C is considered in which two classes of traffics with different loss probability constraints are admitted. 'Partial push-out' algorithm is suggested as a loss priority control schemes, and the performance of this algorithm is analyzed when this is adopted in input buffers of the switch. The quque length distribution of input buffers and loss probabilities of each traffic are obtained using a matrix-geometric solution method. Numerical analysis and simulation indicate that the utilization of the switch with partial push-out algorithm satisfying the QOS's of each traffic is much higher than that of the switch without control. Also, the required buffer size is reduced while satisfying the same QOS's.