• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.9
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• pp.1032-1037
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• 2019

In the existing pharmacy automation system, quantity control was carried out only in the memory without first measuring the quantity of the medicine and during the operation of the facility. As a result, the number of drugs that have already been deducted during operation at the time of a facility error has not been managed. Serious problems are caused by important medicines that need to be managed because of lack of quantity control. In addition, the user had to refill the drug when it was exhausted because the user could not know the amount of the drug outside the facility. When the drug was out of stock, the facility was operating with loss of time to restart and the time to replenish the drug. Thus, in this paper, we designed and applied system to control the quantity of medicines frequently by adding displacement sensors to the robot of the facility.

• Journal of Korea Society of Industrial Information Systems
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• v.29 no.1
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• pp.63-76
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• 2024

In this study, we analyzed queue length and sojourn time of discrete-time BMAP/G/1 queues under the workload control. Group customers (packets) with correlations arrive at the system following a discrete-time Markovian arrival process. The server starts busy period when the total service time of the arrived customers exceeds a predetermined workload threshold D and serves customers until the system is empty. From the analysis of workload and waiting time, distributions of queue length at the departure epoch and arbitrary time epoch and system sojourn time are derived. We also derived the mean value as a performance measure. Through numerical examples, we confirmed that we can obtain results represented by complex forms of equations, and we verified the validity of the theoretical values by comparing them with simulation results. From the results, we can obtain key performance measures of complex systems that operate similarly in various industrial fields and to analyze various optimization problems.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.4
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• pp.286-294
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• 2014

The purpose of this study is to investigate the effects of applying density current generator (hereafter referred to as DCG to large lakes on the operating conditions of DCG, de-stratification, water quality improvement and inhibition of algae occurrence. As a result of a survey conducted to derive the optimum operating parameters of DCG in a condition to minimize eco-toxicity, the following conclusions were obtained. During the survey period, a marked stratification appeared in September to October 2011 and May 2012. At this time, the average depth of water to form thermocline was found to be $5{\pm}2$ m, so the location of discharge port for the operation of DCG was determined to be about 5 m below from the surface. To minimize the adverse effects of benthos and obtain the effect of water mixture at the time of water circulation, the mixing ratio of surface water and deep water was designed to be 3:1 by means of ecotoxicological assessment on the DCG operating characteristics. To select the appropriate operating hours for DCG, DCG was operated by 12 hr, 24 hr, 36 hr and 48 hr. As its result, the formation of thermocline did not occur during the operation of 36 hr. Also, It was effected that start reoperating from 3rd day after stop 2days under the condition of operated during 36 hr with calculated power consumption. Under the above conditions, the results of DO and water temperature analysis during the operation of DCG showed that the stratification, which was distinct previously, appeared to be weak, and relatively lower levels than those before operation were found as a result of water quality analysis on COD and chlorophyll-a, which leads to the conclusion that the water body is maintained at a stable condition due to the circulation of water by the occurrence of density current resulting from the operation of DCG.

• Journal of Chest Surgery
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• v.35 no.12
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• pp.847-853
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• 2002

We previously published the data that proved the safety of retrograde cerebral perfusion for 120 minutes. At this time, we planned to check the neuron-specific enolase and S100-$\beta$ in serum and urine to assess the possibility of early detection of cerebral injury. Material and Method: We used pigs(Landrace species) weighing 35 kg and performed RCP for 120 minutes. After the weaning of cardiopulmonary bypass, we observed the pigs for another 120 minutes. Systemic arterial pressure, central venous pressure, and serum and urine levels of neuron-specific enolose (NSE) and S100$\beta$ protein were checked. Central venous pressure during RCP was maintained in the range of 20 to 25 mmHg. Result: Serum levels of NSE(ng/$m\ell$) were 0.67$\pm$0.18(induction of anesthesia), 0.53$\pm$0.47(soon after CPB), 0.44$\pm$0.27(20min alter CPB), 0.24$\pm$0.09(RCP 20min), 0.37$\pm$0.35(RCP 40min), 0.33$\pm$0.21 (RCP 60min), 0.37$\pm$0.22(RCP 80min), 0.41$\pm$0.23(RCP 100 min), 0.48$\pm$0.26(RCP 120min), 0.42$\pm$0.29(30min after rewarming), 0.35 $\pm$0.32(60min after rewarming, 0.42$\pm$0.37(CPBoff 30min), 0.47$\pm$0.34(CPBOff 60min), 0.47$\pm$0.28(CPBOff 90min), and 0.57$\pm$0.29(CPBOff 120min). There was no statistically significant difference in levels between before and after RCP(ANOVA, p＞0.05). Urine levels of NSE also showed no statistically significant difference in levels between before and after RCP. There was no correlation between urine and serum levels of NSE(Pearson correlation, p＞0.05). Serum levels of S100$\beta$ protein(ng/$m\ell$) during the same time frames were 0.14$\pm$0.08, 0.15$\pm$0.07, 0.22$\pm$0.15, 0.23$\pm$0.07, 0.28$\pm$0.10, 0.40$\pm$0.05, 0.47$\pm$0.03, 0.49$\pm$0.12, 0.43$\pm$0.11, 0.46$\pm$0.15, 0.62$\pm$0.17, 0.77$\pm$0.21, 0.78$\pm$0.23, 0.77$\pm$0.23, and 0.82$\pm$0.33. There was statistically significant difference in levels between before and after RCP(ANOVA, p＜0.05). Urine levels of NSE also showed statistically significant difference in levels between before and after RCP(ANOVA, p＜0.05). There was significant correlation between urine and serum levels of NSE(Pearson correlation, p＜0.05). Conclusion: The author observed the increase in serum and urine levels of S100$\beta$ after 120 minutes of RCP. Significant correlation between serum and urine levels was observed. The results were considered to be the fundamental data that could correlate this study with human-based study.

• Journal of Chest Surgery
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• v.40 no.12
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• pp.855-858
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• 2007

A left ventricular rupture might be one of the most disastrous complications after a mitral valve replacement. An acute atrioventricular groove rupture (type I) was detected in a 54-year-old female diagnosed with a mitral stenosis combined with severe tricuspid regurgitation. She had a prior medical history of an open mitral commissurotomy in Japan at 30 years ago. The surgical findings suggested that the previous procedure was not a simple commissurotomy but a commissurotomy combined with a posteromedial annuloplasty procedure. After a successful mitral valve replacement and a measured (De Vega type) tricuspid annuloplasty, the weaning from a cardiopulmonary bypass was uneventful. However, copious intraoperative bleeding from the posterior wall was detected and the cardiopulmonary bypass was restarted. Exposure of the posterior wall of the left ventricle showed bleeding from the atrioventricular groove 3 cm lateral to the left atrial auricle. Under the impression of a Type I left ventricular rupture, epicardial repair (primary repair of the Teflon felt pledgetted suture, continuous sealing suture using auto-pericardial patch and application of fibrin-sealant) was attempted. Successful local control was made and the patient recovered uneventfully. The patient was discharged at 14 postoperative days without complications. We report this successful epicardial repair of an acute type I left ventricular rupture after mitral valve replacement.

• Economic and Environmental Geology
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• v.50 no.2
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• pp.159-170
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• 2017

The temporal and spatial temperature distribution of the heat storage mortar made of porous feldspar was measured and the thermal properties and electricity consumption were analyzed. For the experiment, two real size chambers (control model and test model) with hot water pipes were constructed. Two large scale models with hot water pipes were constructed. The surface temperature change of the heat storage layer was remotely monitored during the heating and cooling process using infrared thermal imaging camera and temperature sensor. The temperature increased from $20^{\circ}C$ to $30^{\circ}C$ under the heating condition. The temperature of the heat storage layer of the test model was $2.0-3.5^{\circ}C$ higher than the control model and the time to reach the target temperature was shortened. As the distance from the hot water pipe increased, the temperature gap increased from $4.0^{\circ}C$ to $4.8^{\circ}C$. The power consumed until the surface temperature of the heat storage layer reached $30^{\circ}C$ was 2.2 times that of the control model. From the heating experiment, the stepwise temperature and electricity consumption were calculated, and the electricity consumption of the heat storage layer of the test model was reduced by 66%. In the cooling experiment, the surface temperature of the heat storage layer of the test model was maintained $2^{\circ}C$ higher than that of the control model. The heat storage effect of the porous feldspar mortar was confirmed by the temperature experiment. With considering that the time to reheat the heat storage layer is extended, the energy efficiency will be increased.

• Journal of the Korean Institute of Gas
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• v.16 no.4
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• pp.52-58
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• 2012

Recently, waste gas incineration is increasing due to strong environmental regulatory system in Korea. These incinerating facilities are usually connected with the top of the storage tank through pipeline and incinerate off gas with the flame. Therefore, the flame originated from these facilities is likely to move back into pipeline and might cause an explosion of the storage tank. Accordingly, the purpose of this study is to suggest the preventive measures and the way to improve the safety of these incineration systems through the cause analysis of a major industrial accident occurred in a acrylic acid manufacturing process in Korea. As a result of the study, the preventive measures are suggested as follows. (1) Air or inert gas inflow facilities should be well designed to dilute flammable gases into air or inert gas sufficiently before the blower is restarted in order to prevent the explosion (2) It is needed for the detonation-type flame arresters to be installed on the top of the storage tanks. (3) In case of using the deflagration-type flame arresters, it is necessary to install a rupture disk before the arresters, or blow off the flame outside tanks by connecting the tank top and the incinerator with hood-type pipe. (4) TDR should be installed to be restarted automatically after the momentary power failure.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.3
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• pp.234-240
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• 2010

The effectiveness of adding powdered zeolite and granular activated carbon (GAC) before starvation into biological reactor for recovering its performances was investigated. Two types of carrier addition in Sequencing Batch Reactor (SBR) system for non-saline and saline wastewater were evaluated after starvation periods. During the experiment, settleablity (SVI), floc size, fractal dimension, $COD_{Mn}$, T-N, T-P removal efficiencies and recovery time were monitored. When the wastewater feeding was resumed after starvation period for 5days, the SVI increased at the beginning of resumption and then decreased with time in both types. And the larger the floc size and fractal dimension of floc, the more increased removal efficiency for $COD_{Mn}$, T-N and T-P was also. Its performance recovery was strongly correlated with floc size and fractal dimension of activated sludge. After resuming the wastewater feeding, the SVI, floc size, fractal dimension, $COD_{Mn}$, T-N, T-P removal efficiency of SBR with carrier improved and reached its initial value faster compared to those of SBR without carrier.

• KEPCO Journal on Electric Power and Energy
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• v.5 no.1
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• pp.25-32
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• 2019

K-BEMS System was introduced to reduce peak load and to save total energy of the 200 buildings that KEPCO headquarter and branch offices use. And K-BEMS system is composed of PV, battery, and hybrid PCS. KEPCO research institute has carried out this K-BEMS research project for 3 years since January 2016. In this paper, the results of the project are shown. 9 modes of test results of K-BEMS system and are operational problems were analyzed. And measures to cure the trouble are also suggested. Batteries are operated more than 20% of SOC, and less than 20% of SOC battery protection switches are automatically shutting down the system and the system no longer respond to EMS, ending the supply of PV, and so therefore to continue the PV power supply it was turn out to be necessary that the EMS should automatically change its policy to change PV only supply mode automatically when the Battery Switch automatically operated. To operate the system continuously and automatically, it is necessary to modify the minimum operational SOC value, and in addition to that the EMS computer must remember the last shut-down SOC and Voltage which interrupted the system and add some margin to reflect the measurement error in the system.

• Journal of the Korea Society of Computer and Information
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• v.27 no.2
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• pp.125-134
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• 2022

In this paper, we propose an extension method of the BR2K technique for enhancing the robustness of blockchain application services. The BR2K (Blockchain application, Replication & Recovery technique using Kubernetes) technique was recently developed to support the robustness of blockchain services through service replication and rapid restart. The proposed technique extends the existing BR2K technique to provide a state version, which is meta-information about the service state, and a method for safely managing it, and use the state version to determine the timing for service state recovery. Also, the technique provides systematic service state backup for service recovery and joining of new service nodes by utilizing the version information and the service registry which acts as a service recovery center in the BR2K technique. Based on this, it is possible to support new service nodes to join the replication service with consistency. As a result, new service nodes can be quickly added to the BR2K service in operation, enhancing the robustness of the BR2K service. In addition, the extended method is applied to the pilot blockchain application service and tested in a Kubernetes environment composed of virtual machines to confirm the validity of service replication consistency and rapid service recovery in the event of node failures.