• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.196-199
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• 2005

We propose a strategy to manage temporal data which are occurred on scientific applications. Firstly, We define LB and RB to separate temporal data, and entity versions to be stored in past, current, future segments. Also, We describe an algorithm to migrate temporal data with hotspot distribution among segments. The performance evaluation of average response time and space utilization is conducted. Average response time between two methods is similar, and spare is saved in proposed method.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.15 no.1
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• pp.1-17
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• 2011

A new method for option pricing based on the trinomial tree method is introduced. The new method calculates the local average of option prices around a node at each time, instead of computing prices at each node of the trinomial tree. Local averaging has a smoothing effect to reduce oscillations of the tree method and to speed up the convergence. The option price and the hedging parameters are then obtained by the compact scheme and the Richardson extrapolation. Computational results for the valuation of European and American vanilla and barrier options show superiority of the proposed scheme to several existing tree methods.

• Journal of Korea Multimedia Society
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• v.18 no.10
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• pp.1189-1196
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• 2015

In this paper, we proposed automatic extraction of brain tumor using morphological operation and statistical tumors size in MR images. Neurosurgery have used gamma-knife therapy by MR images. However, the gamma-knife plan systems needs the brain tumor regions, because gamma-ray should intensively radiate to the brain tumor except for normal cells. Therefore, gamma-knife plan systems spend too much time on designating the tumor regions. In order to reduce the time of designation of tumors, we progress the automatical extraction of tumors using proposed method. The proposed method consist of two steps. First, the information of skull at MRI slices remove using statistical tumors size. Second, the ROI is extracted by tumor feature and average of tumors size. The detection of tumor is progressed using proposed and threshold method. Moreover, in order to compare the effeminacy of proposed method, we compared snap-shot and results of proposed method.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.4
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• pp.340-345
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• 2003

In order to choose the manufacturing method for extracting alginates from sea tangle, Laminaria japonica, three methods were applied. In Method I, alginates were extracted with NaOH solution from sea tangle powder and extracted alginates were precipitated and converted to alginic acid by $CaCl_2$ and HCI solution. Then alginic acid was converted to sodium alginates with $Na_2CO_3$ solution. Sodium alginates were precipitated with methyl alcohol and were resolved with hot water and this step was repeated three times. Method II was same to Method I except final step including that sodium alginates were precipitated and washed with methyl alcohol three times. Method III included that sodium alginates were extracted with $Na_2CO_3$ solution from sea tangle powder then sodium alginates were precipitated and washed with methyl alcohol three time. Extracting time increased with Increasing extracted alginates amounts but increasing rates were below $0.4\%/h.$ Alginates amounts recovered by Method III showed above 2 times more to those by Method I and II. Extracting time increased with increasing ash amount of sodium alginates but increasing rates were below $0.1\%/h.$ and that of sodium alginates extracted by Method III showed higher value $(5\%)$ than those by Method I and II. In the sodium alginates prepared by Method III, the amount of ash in alginates dried by air was $34.4\%,$ that by vacuum freeze drying was $47.8\%.$ Extracting time increased with decreasing average molecular weight (MW) and degree of polymerization (DP) of sodium alginates, MW and DP of alginates prepared by Method III were higher than those by Method I and II In same extracting time. Extracting time increased with decreasing rate of apparent viscosity change (SAV) of alginates solution, and SAV of alginates prepared by Method III showed higher value than those by Method I and II in same extracting time. SAV of alginates dried by air was higher than that by vacuum freeze drying. Relating equation among SAV MW and DP were MW = 60.066 (SAV) -93.950, DP =309.760 (SAV) -485.084 and MW = 0.914 (DP)+0.213.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.12
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• pp.3202-3218
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• 1994

Mode shapes and natural frequencies of vibrating laminated composite plates are taken using real-time and time-average holographic interferometry. Debonds and delamination in the laminated plates are measured nondestructively. During holographic testing of composite plates, it has been found that the conditions for the local resonance in debonds are strongly dependent on the frequency of excitation. A membrane resonance model was proposed to describe this behavior. Relations between characteristic length according to the size, shape of debonds and membrane resonance frequency are presented. Several experiments were performed to verify the membrane resonance model. The agreements between the predicted excitation frequency and the observed resonance frequency are good. The experimental results show that higher stresses and strains due to local resonance lead to the debond detection.

• Child Health Nursing Research
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• v.10 no.3
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• pp.282-290
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• 2004

Purpose: The measure the degree of computer game addiction; to examine the relationship between computer game addiction and contributing factors; and to discover the predictors of computer game addiction of elementary school children of Korea. Method: Data were assembled from questionnaires distributed among 455 children from four elementary schools in Gyung-buk Province. Result: The level of computer game addiction of subjects was rather low, and correlated significantly with gender, academic performance, family economic status, playmates for leisure time, place of playing computer game, length of the habit of playing game, average playing time of game per day, frequency of PC-room(Internet Cafe for game) visits per week, game partners and reasons for playing game. Multiple regression analysis showed that 45％ of the computer game addiction was significantly related to gender(21％), impulsiveness(10％), average playing time of game per day(9％), depression(2％) and other variables(3％) such as playmates for leisure time, academic performance and frequency of PC-room visits per week. Conclusion: We suggest these results be used to develop a computer game addiction prevention program.

• Journal of Korea Multimedia Society
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• v.25 no.6
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• pp.807-818
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• 2022

In order to further improve the accuracy and time efficiency of behavior recognition in intelligent monitoring scenarios, a human behavior recognition algorithm based on YOLO combined with LSTM and CNN is proposed. Using the real-time nature of YOLO target detection, firstly, the specific behavior in the surveillance video is detected in real time, and the depth feature extraction is performed after obtaining the target size, location and other information; Then, remove noise data from irrelevant areas in the image; Finally, combined with LSTM modeling and processing time series, the final behavior discrimination is made for the behavior action sequence in the surveillance video. Experiments in the MSR and KTH datasets show that the average recognition rate of each behavior reaches 98.42% and 96.6%, and the average recognition speed reaches 210ms and 220ms. The method in this paper has a good effect on the intelligence behavior recognition.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.4
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• pp.291-298
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• 2015

In this study, the reverberation time of apartment living room was measured and distribution of the reverberation time was analyzed. In addition, sound field characteristics of mock-up test room similar with living room and timber structured bedroom was investigated with addition of furniture and sound absorption material. Average reverberation time of unfurnished apartment unit was 1.11 s, and reverberation time in 630 Hz~2000 Hz bands were longer than 1.2 s. It was found that from the field measurement results, reverberation time characteristic of furnished apartment living room was uniform in most of frequency bands. Averaged reverberation time of furnished living room was 0.48 s and the reverberation time of bedroom was 0.44 s. Standardized sound pressure level correction values were calculated from the average reverberation time of furnished and unfurnished apartment units. The correction value of unfurnished living room was −3.4 dB and that of furnished living room was 0.2 dB. Measured reverberation time of furnished and unfurnished apartment units indicated that reference reverberation time; 0.5 s, in KS and ISO standards is reasonable also in Korean residential environment.

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.3
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• pp.581-589
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• 1997

42 dentally handicapped patients who require general dental treatments but behavioral managements had been an obstacle to proper treatments were chosen and the author conducted dental treatment under outpatient general anesthesia. Followings are the conclusions 1. The average time for the treatment procedure was 2 hours and 1 minute and the average of 9.52 teeth were treated for individual patient indicating its high efficiency. 2. The average time for the recovery was 3 hours and 14 minutes and none of the patients showed any specific serious complications. 3. Treatments under outpatient general anesthesia can be a proper patient management method for the dentally handicapped patients if the patient selection is proper.

• Journal of Electrochemical Science and Technology
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• v.8 no.2
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• pp.115-123
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• 2017

Electrochemical noise signals in many cases exhibit a DC drift that should be removed prior to further data analysis. Polynomial fitting and moving average removal method have been used to remove trends of electrochemical noise (EN) in time domain. The corrosion inhibition of synthesized schiff base N,N'-bis(3,5-dihydroxyacetophenone)-2,2-dimethylpropandiimine on API-5L-X70 steel in hydrochloric acid solutions were used to study the effects of drifts removal methods on noise resistance calculation. Also, electrochemical impedance spectroscopy (EIS) was used to study the corrosion inhibition property of the inhibitor. The results showed that for the calculation of $R_n$, both methods were effective in trend removal and the polynomial with m=4 and MAR with p=40 were in agreement.