• Proceedings of the Korean Operations and Management Science Society Conference
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• 2000.10a
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• pp.71-74
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• 2000

Due to the complexity of parts flow and limited resources, FMS(Flexible Manufacturing System) develops blocking, starvation and deadlock problems, which reduce its performance. In order to minimize such problems buffers are imposed between workstations of the manufacturing lines. In this paper, we are concerned with finding the optimal buffer allocation with regard to maximizing system throughput in limited total buffer capacity situation of FMS. A grouping heuristic to solve the buffer allocation problem is proposed. Computer simulation using Arena will be experimented to show the validation of the proposed algotithm.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.407-410
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• 1997

This paper analytically derives the variance of service time of a station in the symmetric IEEE 802.4 token bus network with single access class and finite buffer capacity. This performance measure is represented in terms of the total number of stations, the token hold time, the arrival rate of frames, the service rate, and other parameters. Using computer simulations, presented performance measure is validated.

• Journal of the Korean Geotechnical Society
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• v.34 no.1
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• pp.17-24
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• 2018

A buffer in a geological disposal system minimizes groundwater inflow from the surrounding rock and protects the disposed high-level waste (HLW) against any mechanical impact. As decay heat of a spent fuel causes temperature variation in the buffer that affects the mechanical performance of the system, an accurate estimation of the temperature variation is substantial. The temperature variation is affected by thermal and material properties of the system such as thermal conductivity, density and specific heat capacity of the buffer, and thus these factors should be properly included in the design of the system. In particular, as the thermal properties are variable depending on the density and water content of the buffer, consideration of the effects should be included in the analysis. Hence, in this study, a numerical model based on finite element method (FEM) which is able to consider the change of density and water content of the buffer was established. In addition, using the numerical model, a parametric study was conducted to investigate the effect of each thermal property on the temperature variation of the buffer.

• Journal of Food Hygiene and Safety
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• v.9 no.1
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• pp.23-30
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• 1994

When three systems commonly used for screening(washed platelets suspended in uffer containing Ca2+, washed platelets in buffer without Ca2+and platelet rich plasma) are compared by studying the anti-aggregating capacity of garlic extract, platelet rich plasma was the least sensitive system. The most sensitive assay system, based on the IC50s of garlic extract and 2 other platelet aggregation-inhibiting agents(vitamin K3 and propranolol), was the platelet preparation without Ca2+in the suspension buffer. This system was confirmed as the most sensitive during subsequent investigation of garlic extract's capacity to inhibit platelet ATP release. These results suggest that applying the system with washed platelet without Ca2+is most effective to screen for the anti-affregating capacity of natural food.

• Proceedings of the Korea Society for Simulation Conference
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• 1998.10a
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• pp.128-132
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• 1998

This research is concerned with buffer management in a multi-cell FMS(Flexible Manufacturing System) with an AGVS(Automated Guided Vehicle System). To reduce blocking and starving caused by breakdowns, variablility in process times, and diversity of part routing, buffer is needed. Due to the high per unit buffer cost, which primarily consists of floor space and equipment cost, the total capacity of buffers in an FMS is very limited. Therefore, proper buffer management can provide a high system efficiency. This paper presents a buffer management model for a multi-cell FMS with an AGVS and a simulation study to compare the proposed model to a conventional buffer management model in a job shop FMS.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.7B
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• pp.528-535
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• 2012

This paper proposes silence drop first(SDF) active buffer management algorithm to increase the voice capacity when silence suppression is used. This algorithm finds and drops silence packet rather than voice packet in the queue for resolving buffer overflow of queue. Simulations with voice codec of G.729A and G.711 are performed. By using proposed SDF algorithm, the voice capacity is increased by 84.21% with G.729A and 38.46% with G.711. Further more, SDF algorithm reduces the required link capacity and loosens the silence packet inter-arrival time limit to provide target voice quality compared with that of conventional algorithms.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.6
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• pp.378-382
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• 2004

Soil pH is an important indicator for soil reactions and crop growth. pH buffer capacity and lime requirements are necessary to comprehend and manage soils well. The characteristics related with soil pH were analyzed and 5 field trials were conducted to elucidate pH buffer capacity of soil and lime requirements and liming factor for Korean acid soils. Soil minerals were analyzed for the soil of 2 years after treating $CaCO_3$ using X-ray diffraction. The amount of neutralized $H^+$ was regarded as the exchangeable aluminium overcoming ${\Delta}pH$, because pH buffer capacity of soil depended on exchangeable aluminium. Lime requirement was somewhat similar to the KCl exchangeable aluminium and it was also affected by the exchangeable cation by added lime. X-ray diffraction analyses revealed that an aluminium dissociation from Korean acid soils was equilibrated with kaolin minerals and changed into anorthite ($CaAl_2Si_2O_8$) by neutralizing with $CaCO_3$. Neutralizing process was composed of changing process of $Al^{3+}$ into $H^+$ and $Al(OH)_4{^-}$ ionic species and of neutralizing $H^+$ by, the amount of which was lime requirement. The fact that anorthite dissociates an aluminium ion higher than kaolinite does enabled to consider a liming factor (LF) the content of exchangeable cation and ${\Delta}pH$, $LF=1.5+0.2{\times}{\sum} Cations{\times}{\Delta}pH$.

• Journal of dental hygiene science
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• v.21 no.3
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• pp.150-157
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• 2021

Background: Stress as a cause of mental health problems is known to be more prevalent in women than in men and has a negative effect on several aspects of physical health, such as the composition of blood and saliva. This study investigated the relationship of perceived stress with blood cell counts, saliva flow rate, and saliva factors. Methods: We recruited women in their 20s with a high prevalence of stress. Stress was evaluated using the Korean version of the perceived stress scale. Blood tests included white blood cell, hemoglobin, and platelet. We then examined the saliva flow rate and cariogenic bacteria level, acidity, occult blood, buffer capacity, leukocyte level, protein level, and ammonia level using rinse water with the SILL-Ha^Ⓡ saliva test system. Results: In a total of 70 participants, the average age was 21.64 years old, the average perceived stress score was 16.96±4.32, and high levels of stress were reported by 80% of the participants (n=56). The high-stress group had lower hemoglobin levels. In addition, the high-stress group showed a lower saliva flow rate than the low-stress group, and there was a difference in the salivary acidity and buffer capacity. The total perceived stress score showed a positive correlation with acidity and negative correlation with buffer capacity and the hemoglobin level. Conclusion: This study found that stress in female college students might affect the composition of blood and saliva. High levels of stress were positively correlated with the hemoglobin level, saliva flow rate, and acidity and negatively correlated with the buffer capacity.

• Journal of the Korean Geotechnical Society
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• v.33 no.10
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• pp.25-31
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• 2017

The buffer is one of the major components of an engineered barrier system (EBS) for the disposal of high-level radioactive waste (HLW). As the buffer is located between a disposal canister and host rock, it is indispensable to assure the disposal safety of high-level radioactive waste. It can restrain the release of radionuclide and protect the canister from the inflow of groundwater. Since high quantity of heat from a disposal canister is released to the surrounding buffer, thermal properties of the buffer are very important parameters for the analysis of the entire disposal safety. Especially, temperature criteria of the compacted bentonite buffer can affect the design of HLW repository facility. Therefore, this paper investigated thermal properties for the Kyungju compacted bentonite buffer which is the only bentonite produced in South Korea. Hot wire method and dual probe method were used to measure thermal conductivity and specific heat capacity of the compacted bentonite buffer according to the temperature variation. Thermal conductivity and specific heat capacity were decreased dramatically when temperature variation was between $22^{\circ}C{\sim}110^{\circ}C$ as degree of saturation decreased according to the temperature variation. However, there was little variation under the high temperature condition at $110^{\circ}C{\sim}150^{\circ}C$.

• IE interfaces
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• v.14 no.4
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• pp.348-355
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• 2001

This paper suggests a detailed design of APS(Advanced Planning & Scheduling) system using the DBR (Drum-Buffer-Rope) which is a finite capacity scheduling logic of TOC(Theory of Constraints). Our design is composed of four modules; Network, Buffer, Drum and Subordination. The Network module defines the Product Network which is built from BOM and routings. The Buffer module inserts the Buffers into the Product Network. The Drum module describes detail procedures to create Drum Schedule on the CCR(Capacity Constraint Resource). The Subordination module synchronizes all non-constraints to the constraints by determining the length of Rope. This design documented by ARIS.