• Journal of Life Science
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• v.9 no.2
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• pp.194-200
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• 1999

Grinding aid is a necessary unit operation when the raw materials are handled in solid form, and the purpose is to improve the bioavailability by reducing the particle size. For the particle design of pefloxacin, the dry planetary ball-mill was used. With the drying process, 330 g of zirconia ball with its size of 2 mm in diameter and 10 g of pefloxacin were transferred to the pot and mixed well. The mixture was ground at 112 rpm (60 Hz) for 15, 30, and 60 min, respectively. The most satisfactory grinding products were generated at 15 min of grinding time for their particle size. The volume mean diameter $\X_50$ of the grinding products was 2.97 $\mu$m. X-ray diffraction (XRD), differential scanning calorimeter (DSC), and infrared spectroscopy (IR) patterns were relatively unchanged before pulverizing pefloxacin and in the progress of grinding. Thus, these results suggest that this pulverizing method can be used for grinding products without evident effect on stability of the drug pefloxacin. Dissolution test was carried out to set up the optimal detective condition against residual antibacteria of fish by HPLC. The grinding pefloxacin for 15 min is most effective in dissolution test.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.3
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• pp.166-174
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• 2000

Anchovy, EngrauEis japonica scoop nets are used in the coastal of Southern and Cheju of Korea. Especially in the Cheju, the fishing gear of scoop nets consists of upper boom, lower boom, pressing stick and bag net. They are operated by fishing boats of 6 to 10 ton class and 8 persons on board. The booms are controlled by side drum, and the net and pressing stick are hauled by only human power in operating. Therefore this fishery needs to large labor and heavy human power and has much risk. Three kinds of hydraulic winding device which controls two booms was designed and manufactured to reduce heavy labor force of scoop nets, and trial in the sea was carried out to test their performances using the commercial fishing boats of 6 ton class. The proper capacity of hydraulic pump and motor were determined by model test of boom 1/5 scale. The results obtained are as follows, 1. Tension of boom which is being drawn was the strongest and 187.5kgf when the boom's end is in the depth of 4m under the water. 2. The hydraulic motor of the fittest kind of winder has the least leakage per time than the other kinds. 3. In the best type of several winder devices, when the pressure difference was fixed $130kg/^2$ for the safe fishery, the winding velocity of boom line was 2m/sec, is faster 0.48/sec than traditional fishing method and this winder can catch the anchovy of 1.6 tonnage. 4. As a result, the crew were decreased from 8 to 6 and the problem of heavy human power and risk on fishing operation were solved by using the this winder.

• Journal of Trauma and Injury
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• v.24 no.2
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• pp.89-94
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• 2011

Purpose: A few studies have assessed the factors affecting the prognoses for major trauma patients and those improving the circumstances when dealing with the trauma system. In that light, we analyzed factors, such as pre-hospital factors, the time to admission, the length of stay in the emergency department (ED) and emergency operation, influencing the outcomes for trauma patients. Methods: The patients who visited our emergency department from April 1, 2009, to February 29, 2011, due to major trauma were enrolled in the study. The inclusion criterion was a revised trauma score (RTS) < 7 or injury severity score (ISS) ${\geq}$ 16. We used reviews of medical records, to analyze each step of emergency medical care with respect to patients' sex, age, visit time and visit date. Continuous variables were described as a median with an interquartile range, and we compared the variables between the survival and the mortality groups by using the Mann-Whitney U test. Fisher's exact test was used for nominal variables. Using the variables that showed statistical significance in univariate comparisons, we performed a logistic regression analysis, and we tested the model's adequacy by the using the Hosmer-Lemeshow method. Results: A total of 261 patients with major trauma satisfied either the RTS score criterion or the ISS score criterion. Excluding 12 patients with missing data, 249 patients were included in this study. The overall mortality rate was 16.9%. Time to ED arrival, time to admission, time of ED stay, RTS, ISS, and visit date being a holiday showed statistically significant differences between the survival and the mortality groups in the univariate analysis. RTS, ISS, length of ED stay, and visit date being a holiday showed statistical significance in the multivariate analysis. Conclusion: The mortality rate did not show a significant relationship with the time to ED arrival, use of 119, on time to admission. Rather, it elicited a quite significant correlation with the trauma scoring system (RTS and ISS), the time of ED stay, and the visit date being a holiday.

• Journal of Welding and Joining
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• v.33 no.5
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• pp.26-30
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• 2015

Hastelloy X in this study was applied in jet engine F-15 air fighter as shroud to isolate the engine from outer skin. After 15 years operation at elevated temperature the mechanical properties decreased gradually due to the precipitation of continues second phases in the grain boundaries and precipitated inside the grain. The crack happened at the edge of the shroud due to the thermal and mechanical stress from jet engine. Selective TEM analysis found that the grain boundaries consist of $M_{23}C_6$ carbide, $M_6$ Ccarbide and small percentage of sigma(${\sigma}$) phase. Furthermore, it was confirmed the nano size of ${\sigma}$ and miu (${\mu}$) phase inside the grain. In this study, it was investigated the microstructure of the degraded shroud component and HAZ of repair welded shroud. In the HAZ, it was observed the dissolution of the $M_{23}C_6$ carbides and smaller precipitates, the migration of the undissolved larger $M_{23}C_6$ carbide and $M_6$ Ccarbide. It is also observed the liquation due to the simply melt of the segregated precipitates in the grain boundaries. Interestingly, the segregated second phases which simply melt in the grain boundaries more easily happened at higher heat input welding condition. High temperature tensile test was done at $300^{\circ}C$, $700^{\circ}C$ and $900^{\circ}C$. It was obtained that the toughness of welded sample is lower compare to the non-welded sample. The solution heat treatment at $1170^{\circ}C$ for 5 minutes was suggested to obtain a better mechanical properties of the shroud. The high cycle fatigue number of the repair welded shroud shows a much lower compare to the shroud. In addition, the high cycle fatigue number at room temperature after solution heat treatment was almost double compare to the before solution heat treatment under 420-500MPa stress amplitude. However, the high cycle fatigue number of repaired welded sample was shown a much lower compare to the non- welded shroud and solution treated shroud. One of the main reasons to decrease the tensile strength and the high cycle fatigue properties of the repair welded shroud is the formation of the liquid phase in HAZ.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.1
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• pp.103-114
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• 2017

A membrane bioreactor by sequentially alternating the inflow and by applying a two-stage coagulation control based on pre-coagulation was evaluated in terms of phosphorus removal efficiency and cost-savings. The MBR consisted of two identical alternative reaction tanks, followed by aerobic, anoxic and membrane tanks, where the wastewater and the internal return sludge alternatively flowed into each alternative reaction tank at every 2 hours. In the batch-operated alternative reaction tank, the initial concentration of nitrate rapidly decreased from 2.3 to 0.4 mg/L for only 20 minutes after stopping the inflow, followed by substantial release of phosphorus up to 4 mg/L under anaerobic condition. Jar test showed that the minimum alum doses to reduce the initial $PO_4$-P below 0.2 mg/L were 2 and 9 mol-Al/mol-P in the wastewater and the activated sludge from the membrane tank, respectively. It implies that a pre-coagulation in influent is more cost-efficient for phosphorus removal than the coagulation in the bioreactor. On the result of NUR test, there were little difference in terms of denitrification rate and contents of readily biodegradable COD between raw wastewater and pre-coagulated wastewater. When adding alum into the aerobic tank, alum doses above 26 mg/L as $Al_2O_3$ caused inhibitory effects on ammonia oxidation. Using the two-stage coagulation control based on pre-coagulation, the P concentration in the MBR effluent was kept below 0.2 mg/L with the alum of 2.7 mg/L as $Al_2O_3$, which was much lower than 5.1~7.4 mg/L as $Al_2O_3$ required for typical wastewater treatment plants. During the long-term operation of MBR, there was no change of the TMP increase rate before and after alum addition.

• Journal of Satellite, Information and Communications
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• v.6 no.1
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• pp.37-44
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• 2011

COMS(Chollian) satellite which was launched on June 26, 2010 has three payloads for Ka-band communications, geostationary ocean color imaging and meteorological imaging. In order to make efficient use of the geostationary satellite, a concept of mission operations has been considered from the beginning of the satellite ground control system development. COMS satellite mission operations are classified by daily, weekly, monthly, and seasonal operations. Daily satellite operations include mission planning, command planning and transmission, telemetry processing and analysis, ranging and orbit determination, ephemeris and event prediction, and wheel off-loading set point parameter calculation. As a weekly operation, North-South station keeping maneuver and East-West station keeping maneuver should be performed on Tuesday and Thursday, respectively. Spacecraft oscillator updating parameter should be calculated and uploaded once a month. Eclipse operations should be performed during a vernal equinox and autumnal equinox season. In this paper, operational validations of the major functions in COMS SGCS are presented for the first three month of in-orbit test operations. All of the major functions have been successfully verified and the COMS SGCS will be used for the mission operations of the COMS satellite for 7 years of mission life time and even more.

• Journal of Chest Surgery
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• v.29 no.8
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• pp.897-904
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• 1996

A preoperative prediction of postoperative pulmonary function after the pulmonary resection should be made to prevent serious complications and postoperative mortality. There are several methods to predict postoperative lung function but the 99m7c-MAA perfusion lung scan is known as simple, inexpensive and easily tolerated method for patients. We studied the accuracy of the perfusion lung scan in predicting postoperative lung function on 34 patients who received either the resection of one lobe(17 patients) or 2 lobes(2 patients) or pneumonictomy(15 patients). We performed pulmonary function test and lung scan immediately before the operation and calculated the postoperative lung function by substracting the regional lung function which will be rejected. We compared this predictive value to the observed pulmonary function which was done 20 days after the surgery. We also compared the data achieved from 12 patients ho received open thoracotomy due to intrathoracic disease that are not confined in the lung. The correlation coefficient between the predicted value and observed value of FEVI .0 was 0.423, FVC was 0.557 in the pneumonectomy group and FEVI . 0 was 0.693, FVC was 0.591 in the lobectomy group. The correlation coefnclent between the'postoperative value and preoperative value of FEVI .0 was 0.528, FVC was 0.502 in the resectional group and FEVI .0 was 0.871, FVC was 0.896 in the comparatives. We concluded that the perfusion lung scan is accllrate in predicting post-resectional pulmonary function.

• The Korean Journal of Pain
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• v.13 no.2
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• pp.149-155
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• 2000

Background: Pulsed radiofrequency (RF) lesioning is a painless procedure and causes no neurodestruction and neuritis-like reaction are common following conventional RF lesioning. There is little data about the effect of pulsed RF especially with regard to its suitability for the treatment of acute pain. The possibility of a placebo effect cannot be ruled out because a double-blind study was not performed in previous studies. There is also no neuropathologic study about pulsed RF. Methods: The rats were anesthetized with sodium pentobarbital (40 mg/kg, i.p.; supplemented as necessary). The common sciatic nerve was exposed by blunt dissection through biceps femoris. Pulsed RF was administered to the common sciatic nerve using a 30 ms/s pulse with for 120 seconds. The temperature reached was no more than $42^{\circ}C$. Analgesia was determined using hot-plate assay shortly and, 3 days and 1 week before, and 2 weeks after operation. Lesions were examined with LM (light microscope) and EM (electron microscope) 2 weeks later. Results: There were no differences in response latencies between the control and experimental group. There were many vacuoles with hyaline bodies in the Schwann cell cytoplasm rather than axon in LM and larger electron dense bodies. No changes were found in the axon or unmyelinated fibers. Only small changes were found in the sheaths of myelinated fibers and Schwann cells. Conclusions: We therefore do think that any analgesic effect of pulsed RF is not a result of block of neural conduction. But rather than it can be attributed to others factors. It was also ineffective as a treatment for acute pain such as that caused by the hot-plate test.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.6
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• pp.863-871
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• 2013

Recently application of open protocols and external network linkage to the national critical infrastructure has been growing with the development of information and communication technologies. This trend could mean that the national critical infrastructure is exposed to cyber attacks and can be seriously jeopardized when it gets remotely operated or controlled by viruses, crackers, or cyber terrorists. In this paper virtual Honeynet model which can reduce installation and operation resource problems of Honeynet system is proposed. It maintains the merits of Honeynet system and adapts the virtualization technology. Also, virtual Honeynet model that can minimize operating cost is proposed with data analysis and collecting technique based on the verification of attack intention and focus-oriented analysis technique. With the proposed model, new type of attack detection system based on virtual Honeynet, that is Cybertrap, is designed and implemented with the host and data collecting technique based on the verification of attack intention and the network attack pattern visualization technique. To test proposed system we establish test-bed and evaluate the functionality and performance through series of experiments.

• Journal of Korea Multimedia Society
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• v.12 no.5
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• pp.767-776
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• 2009

The purpose of this paper is to design, implement and test the automatic marking system for programming languages using key-words and boolean operations to solve the processing problems of natural languages. There are accurate grammar systems and key-words in programming languages. Using these characteristics, We have designed, programmed, and tested automatic marking system for programming languages through key-words and boolean operations in this paper. We have categorized programming languages into 7 types as the type of answer and when a professor input any key-words, the system make him put conjunction with the special character. It can be logical expressions instantly so that the system easily operates. We asked 10 students who are majoring in computer engineering to take a test on the paper and web to show how well automatic marking system that we have programmed works. Then We requested 3 professors if the subject problems marked objectively. As a result, automatic marking system proved to be appropriate. We have proposed the way of using key-words and boolean operation for prohibiting huge natural language processing in marking of subjective question. It promotes efficiency rate of programming, objectivity and speed through the transferal to the web for marking since the system prohibits marker to include personal opinion on marking and gives feedback quickly