• Journal of the Korean Geographical Society
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• v.40 no.3 s.108
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• pp.321-334
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• 2005

This study aims to calculate reasonable carving capacity of the Gwangneung area and to review its tourism policies from the perspective of the tourist's demands. According to the analysis results, The socio-psychological carrying capacity by targeted intervals of time is generally underestimated and less than desired. Parking lots followed by stores and then roads are the biggest issues weighing down the area's carving capacity Also, another finding shows that the physical carrying capacity, analyzed based on area use, is estimated for 600 tourists and 130 cars. This study recommends following that Gwangneung establish various tour programs linking its cultural and historical sites to forest and ecological resources. Further to this, Gwangneung might be better off exerting efforts to developing environmental education programs and training more cultural and ecological guides. The findings necessitate that should be made off limits to cars, and instead servicing the area with shuttle buses. Management offices can also be classrooms used for cultural, historical and ecological education and exhibitions. Other findings suggest an expansion of convenience facilities such as more potable water stations, benches, resting areas and a continued monitoring of tourism activities in the area.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.405-413
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• 2006

In general mechanical servo systems, friction deteriorates the performance of controllers by its nonlinear characteristics. Especially, friction phenomenon causes steady-state tracking errors and limit cycles in position and velocity control systems, even though gains of controllers are tuned well in linear system model. Even if sensor is used higher accuracy level, it is difficult to improve tracking performance of the position to the same level with a general control method such as PID type. Therefore, many friction models were proposed and compensation methods have been researched actively. In this paper, we consider that the variation of mover's mass is various by loading and unloading. The normal force variation occurs by it an other parameters. Therefore, the proposed control system is composed of main position controller and a friction compensator. A parameter estimator for a nonlinear friction model is designed by adaptive control law and adaptive backstepping control method.

• Journal of Navigation and Port Research
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• v.31 no.1 s.117
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• pp.55-64
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• 2007

In general mechanical servo systems, friction deteriorates the performance of controllers by its nonlinear characteristics. Especially, friction phenomenon causes steady-state tracking errors and limit cycles in position and velocity control systems, even though gains of controllers are tuned well in linear system model. Even if sensor is used higher accuracy level, it is difficult to improve tracking performance of the position to the same level with a general control method such as PID type. Therefore, many friction models were proposed and compensation methods have been researched actively. In this paper, we consider that the variation of mover's mass is various by loading and unloading. The normal force variation occurs by it and other parameters. Therefore, the proposed control system is composed of main position controller and a friction compensator. A parameter estimator for a nonlinear friction model is designed by adaptive control law and adaptive backstepping control method.

• Journal of Pharmaceutical Investigation
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• v.27 no.3
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• pp.181-187
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• 1997

The purpose of this work was to investigate pharmacokinetics of alcohol as a function of dose and time of administration of ethanol. The pharmacokinetics of alcohol 15 min after and before oral administration of aspartate-containing compositions to rats were also evaluated. The retention time of acetaldehyde, alcohol and isopropyl alcohol an internal standard in gas chromatogram was 3.6, 6.0 and 10.5 min, respectively. The maximum concentration of alcohol $(C_{max})$ and area under the blood concentration (AUC) were significanly increased as a function of ethanol dose in a nonlinear fashion. The significant diurnal variation of alcohol pharmacokinetics was also noted, showing fast metabolism and elimination when given orally in the night time. When APAP was given after administration alcohol (1g/kg) to rats, AUC and $C_{max}$ were increased when compared to alcohol only. However, AUC and $C_{max}$ were decreased when aspartate or standard complex compositions containing aceaminophen (APAP, 250mg). sodium L-aspartate(25 mg), dl-methionine (125 mg) and anhydrous caffeine (25 mg) was orally given by coupling malate/asparate shuttle in hepatocyte. The blood alcohol concentration profiles between aspartate and standard complex compositions were similar when given before or after administration alcohol (1g/kg) to rats. No significant difference of administration sequence was observed. However, it was noted that AUC and $C_{max}$ of standard complex compositions given before alcohol administration were significantly lower when compared with alcohol only. Based on these findings, dose, time of administration and composition of drugs to improve alcohol metabolism and elimination were considered to be important in the pharmacokinetics of alcohol. The administration sequence of drug compositions and alcohol might be also considerd.

• Microbiology and Biotechnology Letters
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• v.16 no.6
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• pp.476-483
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• 1988

Yeat-Escherichia coli shuttle vectors were constructed by combination of various functional segments such as autonomous replicating sequence (ARS1), centromere region (CEN3), origin of replication of 2 $\mu$m plasmid (2 $\mu$m OR). Transformation efficiency, stability and copy number of constructed vectors were analyzed in yeast strains, SHY4(cir$^+$) containing 2 $\mu$m plasmid and NNY1(cir$^{\circ}$) without it. The results showed that centromere containing plasmids were very stable and existed at one copy per cell; fused replication system (2$\mu$m OR and ARS1) containing Plasmids were more stable and higher copy number than one replicon containing plasmids ; presence of endogenous 2$\mu$m plasmid influenced on stability and copy number of 2 $\mu$m based plasmids.

• Journal of Microbiology
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• v.43 no.4
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• pp.354-360
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• 2005

Heat-labile enterotoxin B subunit (LTB) of enterotoxigenic Escherichia coli (ETEC) is both a strong mucosal adjuvant and immunogen. It is a subunit vaccine candidate to be used against ETEC-induced diarrhea. It has already been expressed in several bacterial and plant systems. In order to construct yeast expressing vector for the LTB protein, the eltB gene encoding LTB was amplified from a human origin enterotoxigenic E. coli DNA by PCR. The expression plasmid pLTB83 was constructed by inserting the eltB gene into the pYES2 shuttle vector immediately downstream of the GAL1 promoter. The recombinant vector was transformed into S. cerevisiae and was then induced by galactose. The LTB protein was detected in the total soluble protein of the yeast by SDS-PAGE analysis. Quantitative ELISA showed that the maximum amount of LTB protein expressed in the yeast was approximately $1.9\%$ of the total soluble protein. Immunoblotting analysis showed the yeast-derived LTB protein was antigenically indistinguishable from bacterial LTB protein. Since the whole-recombinant yeast has been introduced as a new vaccine formulation the expression of LTB in S. cerevisiae can offer an inexpensive yet effective strategy to protect against ETEC, especially in developing countries where it is needed most.

• Journal of Drive and Control
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• v.13 no.1
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• pp.1-9
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• 2016

Nowadays automatic transmission equipped vehicles prevail in construction and agricultural equipment due to their convenience in driving and operation. Though domestic vehicle manufacturers install imported electronic controlled transmissions at present, overseas products will be replaced by domestic ones in the near future owing to development efforts over the past 10 years. For passenger cars, there are many kinds of shift control algorithms that enhance the shift quality such as feedback and learning control. However, since shift control technologies for heavy duty vehicles are not highly developed, it is possible to improve the shift quality with an organized control method. A feedback control algorithm for neutral-into-gear shift, which is enabled during the inertia phase for the master clutch slip speed to track the slip speed reference, is proposed based on the power transmission structure of TH100. The performance of the feedback shift control is verified by a vehicle test which is implemented with firmware embedded TCU. As the master clutch engages along the predetermined speed trajectory, it can be concluded that the shift quality can be managed by a shift time control parameter. By extending the proposed feedback algorithm for neutral-into-gear shift to gear change and shuttle shift, it is expected that the quality of the shift can be improved.

• Journal of the Korea Society for Simulation
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• v.26 no.3
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• pp.95-104
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• 2017

This study focuses on resolving traffic congestion caused by a large scale event based on the case of ROK Joint Officer Commissioning Ceremony, and it was conducted through literature review as well as Arena Simulation. The study purpose is to appropriately allocate and disperse the traffic by utilizing nearby parking lots of facilities. The annual event draws about 7,400 vehicles to a limited number of parking lots, and all vehicles leave the parking lots concurrently, causing a severe bottleneck near the exit and a few roads. In order to resolve the issue, the optimal number of cars in the event area was analyzed. After the analysis, the study found that the overflow of cars in the event area should be allocated to nearby parking lots of facilities with shuttle buses operating to transport the attendees. As the proposed result of the simulation, the traffic congestion time was reduced from 150 minutes to 64 minutes, a total reduction of 86 minutes.

• Microbiology and Biotechnology Letters
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• v.49 no.3
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• pp.289-297
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• 2021

Bacillus velezensis CJ1, showing significant fibrinolytic activity, was isolated from Myeolchi Jeotgal, a popular Korean fermented seafood. When B. velezensis CJ1 was grown on four different culture media, the culture on the Luria-Bertani (LB) broth showed the highest fibrinolytic activity (102.94 mU/μl) at 48 h. LB was also the best medium for growth. SDS-PAGE of culture supernatant showed four major bands, 38, 35, 27, and 22 kDa in size. Fibrin zymography showed four active bands, 50, 47, 40, and 30 kDa in size. A gene homologous to aprE of the Bacillus species was cloned by PCR. DNA sequencing showed that aprECJ1 can encode a protease consisting of 382 amino acids. The translated amino acid sequence of AprECJ1 showed high identity values with those of B. velezensis strains and other Bacillus species. The aprECJ1 gene was introduced into B. subtilis WB600 using an E. coli-Bacillus shuttle vector, pHY300PLK, and overexpressed. A 27 kDa band corresponding to the mature form of AprECJ1 was produced and confirmed by SDS-PAGE and fibrin zymography. B. subtilis WB600 [pHYaprECJ1] showed 1.8-fold higher fibrinolytic activity than B. velezensis CJ1 at 48 h.

• Korean Journal of Agricultural Science
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• v.48 no.3
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• pp.597-606
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• 2021

Due to the characteristics of the farmland in Korea, forward and reverse shift is the most used. The fatigue of farmers is caused by forward and reverse shifting with a manual transmission. Therefore, it is necessary to improve the convenience of forward and backward shifting. This study was a basic study on the development of a current control system for forward and reverse shifting of agricultural tractors using proportional control valves and a controller. A test bench was fabricated to evaluate the current control accuracy of the control system, and the stability of the controller was evaluated through CPU (central processing unit) load measurements. A controller was selected to evaluate the stability of the proportional valve controller. The stability evaluation was performed by comparing and analyzing the command current of the controller and the actual current measured. The command current was measured using a CAN (controller area network) communication device and DAQ (data acquisition). The actual current was measured with a current probe and an oscilloscope. The control system and stability evaluation was performed by measuring the CPU load on the controller during control operations. The average load factor was 12.27%, and when 5 tasks were applied, it was shown to be 70.65%. This figure was lower than the CPU limit of 74.34%, when 5 tasks were applied and was judged to be a stable system.