• Korean Journal of Environmental Biology
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• v.22 no.1
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• pp.127-132
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• 2004

The purpose of this study was to understand plant community structure in upper zone of Gyeryongsan National Payk. Total 51 plots were set up and surveyed toy this study. The fifty one plots were classified into four communities such as Quereus mongolica community, Carpinus laxiflora community, Pinus densiflora community, and Quercus variabizis community. The Quercus mongotica community were found in 29 plots of the 51 plots and the differential species in the community weve Quercus mongolica, Acer pseudosieboldianum var. koreanum, Arisaema amurense var. serratum, Diarrhena japonica, and Saussurea gyacilis. The Carpinus laxiflora community were found in 10 plots of the 51 plots and the differential species in the community were Carpinus laxiflora, Carpinus cordata, Cornus eontroversa, Carex siderosticta, and Hydrangea serrata for. acuminata. The Pinus densiflora community were found in 7 plots of the 51 plots and the differential species in the community were Pinus densiflora, Lespedeza maximowiczii, Rubus crataegifotius, Miseanthus sinensis, Persicaria filiforme, Artemisia keiskeana, and spodiopogon sibiricus. the Quereus vuriabilis community were found in 5 plots of the 51 plots and the differential species in the community were Quercus variabilis.

• Korean Journal of Environmental Biology
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• v.22 no.1
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• pp.167-170
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• 2004

A self-directing optimization procedure was applied to determine the best environmental factors in operating the bioreactor. The self-directing optimization process was employed to determine the best conditional combination of multi parameters, pH, temperature, aeration rate and mixing rate toy maximal production of chitinase by Trichoderma harzianum SJG-99721 in batch mode fermentation. Among these factors, the parameters of pH and aeration rate were found to be particularly important on mycellial growth and chitinase activity. pH 4.89, an aeration rate of 3.22 ι per minute and an agitation rate of 225 rpm was found to be the best combination. By the optimization, chitinase activity was dramatically increased from an initial value of 4.221 U under basic conditions to n final value of 16.825 U.

• Korean Journal of Environmental Biology
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• v.22 no.1
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• pp.177-183
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• 2004

Cytochrome P45O (CYP) contents and 7-ethoxyresorufin-O-deethylase (EROD) activity were determined in hepatic microsome of olive flounder (Paralichthys olivaceus) exposed to tributyltin chloride (TBTC), tributyltin oxide (TBTO), and triphenyltin chloride (TPTC). In addition, effects of in vivo (intraperitoneal injection of 7.5 mg $kg^{-1}$ BW) exposure of flounder to TPTC on CYP, NADPH cytochrome c reductase, NADH cytochrome b5 yeductase and EROD levels were measured. In in vitro exposure of hepatic microsome to organotins, TBTC, TBTO and TPTC reduced CYP contents and inhibited EROD activity. The TPTC was the strongest inhibitor, which is followed by TBTO and TBTC. The degree of inhibition, especially EROD acitivity, depended on the exposure duration. In addition, all the target enzymes in flounder were inhibited by TPTC with the in vivo exposure to TPTC. As EROD activity was the most sensitive to the inhibitions and demonstrated good reproducibility of the results, it could be used as a helpful tool toy monitor effects of organotin compounds on mixed funciton oxygenase system in marine fish.

• Journal of Korean Society of Transportation
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• v.28 no.4
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• pp.129-139
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• 2010

This study proposes a model for measuring the connectivity of nodes in road networks. The connectivity index between two nodes is characterized by the number of routes, degree of circuitousness, design speed, and route capacity between the nodes. The connectivity index of a node is then defined as the weighted average of the connectivity indexes between the node and other nodes under consideration. The weighting factor between two nodes is determined by the travel demand and distance between them. The application of the model to a toy network shows that it reasonably well quantifies the level of connectivity of nodes in the network. If flow of rail networks can be measured in the same scale as that of road networks and the capacity of rail links can be estimated, the model proposed in this paper could be applied to intermodal transportation networks as well.

• Journal of Veterinary Clinics
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• v.29 no.3
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• pp.259-262
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• 2012

A seven-year-old Yorkshire terrier 2.1 kg was admitted with a 2 months history of sever bilateral forelimb lameness and joint instability. Examination and radiographs revealed caudal luxation of bilateral antebrachiocarpal joint. Luxation of bilateral antebrachiocarpal (ABC) joint in a toy breed dog was treated with pancarpal arthrodesis. Modified external skeletal fixator (ESF) (type IIb) with polymethylmethacrylate (PMMA) was utilized in this case. Porcine cancellous bone graft (PCBG) was inserted to fill the joint space in carpus. The clinical and radiographic assessments of joint after the surgical procedure proved that PCBG can be used a promising alternative to Autogenous cancellous bone graft (ACBG).

• Journal of Veterinary Clinics
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• v.35 no.4
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• pp.137-140
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• 2018

A five-month-old toy poodle was referred for treatment of bilateral mandibular fractures. Preoperative skull and dental radiographs showed rostral mandibular fractures and permanent teeth that had not yet erupted. In addition to providing stability for the healing of fractures, it is very important to focus on restoring normal occlusion. The mandibular fractures were repaired using interdental wiring in a dentate area where the deciduous canines and fourth premolars were stable and could be used to anchor the interdental fixation. In the absence of an erupted permanent mandibular first molar, the modified Risdon wiring was performed using the deciduous mandibular fourth premolars as anchor teeth. An intraoral splint was placed on the mandibular teeth using self-curing composite resin. Five months after surgery, the patient had experienced no complications, and the permanent teeth had erupted normally. In this case, which involves a small-breed puppy with deciduous dentition, treatment with a wire-reinforced interdental splint using intact deciduous fourth premolar teeth as anchor teeth can be considered as a suitable method for rostral mandibular fracture restoration.

• Journal of The Korean Astronomical Society
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• v.46 no.3
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• pp.133-140
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• 2013

The empirical mass discrepancy-acceleration (MDA) relation of disk galaxies provides a key test for models of galactic dynamics. In terms of modified laws of gravity and/or inertia, the MDA relation quantifies the transition from Newtonian to modified dynamics at low centripetal accelerations $a_c{\lesssim}10^{-10}ms^{-2}$. As yet, neither dynamical models based on dark matter nor proposed modifications of the laws of gravity/inertia have predicted the functional form of the MDA relation. In this work, I revisit the MDA data and compare them to four different theoretical scaling laws. Three of these scaling laws are entirely empirical; the fourth one - the "simple ${\mu}$" function of Modified Newtonian Dynamics - derives from a toy model of gravity based on massive gravitons (the "graviton picture"). All theoretical MDA relations comprise one free parameter of the dimension of an acceleration, Milgrom's constant aM. I find that the "simple ${\mu}$" function provides a good fit to the data free of notable systematic residuals and provides the best fit among the four scaling laws tested. The best-fit value of Milgrom's constant is $a_M=(1.06{\pm}0.05){\times}10^{-10}ms^{-2}$. Given the successful prediction of the functional form of the MDA relation, plus an overall agreement with the observed kinematics of stellar systems spanning eight orders of magnitude in size and 14 orders of magnitude in mass, I conclude that the "graviton picture" is sufficient (albeit probably not a necessary nor unique approach) to describe galactic dynamics on all scales well beyond the scale of the solar system. This suggests that, at least on galactic scales, gravity behaves as if it was mediated by massive particles.

• Journal of Korea Game Society
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• v.16 no.6
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• pp.131-142
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• 2016

Recently, a variety of methodologies based on the use of educational coding robots have been proposed and experimented in newly emerging korean educational coding markets. Due to imprecise movement accuracy of the existing coding robots, however, such robots are mainly used as a toy. Inspired by these observations, we developed a simple adjustment method during robot movements, which is based on the observation results of 6 line-tracking sensors: 3 sensors in the center of a robot and other 3 sensors at the front. These sensors help to determine whether the robot is in the right location and whether it rotates as expected. Through the well-designed experiments, we report the effectiveness of our proposed solution: the average distance error of 1.57cm and the average degree error of 2.38 degree before and after complex movements. In near future, we hope our method to be popularly used in various educational coding robot platforms.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.6
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• pp.723-729
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• 2014

When the bluetooth technology of smartphone is applied to a remote control system, communication errors caused by wave attenuation and interference results in the shortening of communication distance, loss of the target device control and malfunctioning. In this study, we propose a method to adopt a retransmission persistence controlled S/W ARQ in bluetooth communication to minimize the effect of the communication failure and to detect and handle the state where the target device gets lost control. We implemented a motor-driven RC car equpped with a bluetooth communication module and a steering application program on smartphone to test the proposed method. The experiments are conducted in three communication environments, and have resulted in the increase of the communication distance by at least 30% when S/W ARQ is applied. Moreover, when the communication was disrupted due to environmental disturbances, the S/W ARQ based system stopped immediately any undergoing operations to avoid possible malfunction.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.11_12
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• pp.587-597
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• 2005

Flash memory based embedded computing systems are becoming increasingly prevalent.These systems typically have to provide an instant start-up time. However, we observe that mounting a file system toy flash memory takes 1 to 25 seconds mainly depending on the flash capacity. Since the flash chip capacity is doubled in every year, this mounting time will soon become the most dominant reason of the delay of system start-up time Therefore, in this paper, we present instant mounting techniques for flash file systems by storing the In-memory file system metadata to flash memory when unmounting the file system and reloading the stored metadata quickly when mounting the file system. These metadata snapshot techniques are specifically developed for NOR- and NAND-type flash memories, while at the same time, overcoming their physical constraints. The proposed techniques check the validity of the stored snapshot and use the proposed fast trash recovery techniques when the snapshot is Invalid. Based on the experimental results, the proposed techniques can reduce the flash mounting time by about two orders of magnitude over the existing de facto standard flash file system, JFFS2.