• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.8B
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• pp.780-786
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• 2002

In this paper several access schemes for voice and data packet over CPCH with waiting time signalling are proposed. Waiting time signalling is used for reducing the excessive attempt of UE when all the CPCH channel resources is being used by other UEs. The proposed schemes in this paper are better than other schemes in view of the voice/data packets? dropping probability, average access attempt to transmit voice/data packets successfully and the average throughput.

• Journal of Information Processing Systems
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• v.9 no.3
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• pp.349-364
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• 2013

The big challenge in current content-based image retrieval systems is to reduce the semantic gap between the low level-features and high-level concepts. In this paper, we have proposed a novel framework for efficient image retrieval to improve the retrieval results significantly as a means to addressing this problem. In our proposed method, we first extracted a strong set of image features by using the dual-tree rotated complex wavelet filters (DT-RCWF) and dual tree-complex wavelet transform (DT-CWT) jointly, which obtains features in 12 different directions. Second, we presented a relevance feedback (RF) framework for efficient image retrieval by employing a support vector machine (SVM), which learns the semantic relationship among images using the knowledge, based on the user interaction. Extensive experiments show that there is a significant improvement in retrieval performance with the proposed method using SVMRF compared with the retrieval performance without RF. The proposed method improves retrieval performance from 78.5% to 92.29% on the texture database in terms of retrieval accuracy and from 57.20% to 94.2% on the Corel image database, in terms of precision in a much lower number of iterations.

• Journal of the Korean Chemical Society
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• v.17 no.4
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• pp.298-305
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• 1973

Following results were obtained for the mechanical degradation of polystyrene (for polystyrene itself and when blended with rubber) by roll mastication. 1) The rate of mechanical degradation for polystyrene itself can be represented by the second-order rate equation proposed by Goto. $-\frac{dP_t}{dt} = k_s(P_t-P_{\infty})^2$ Where Pt is the degree of polymerization of the degraded polymer at t minutes and $P{\infty}$ is the final degree of polymerization. 2) The mechanical degradation of polystyrene component in the polystyrene-rubber (SBR, BR) blend system occurred similarly as that of polystyrene itself. 3) Under the experimental conditions the mechanical degradation rate of the polystyrene component of the polystyrene-rubber, (SBR, BR) blend system followed approximately the same second-order equation as that for polystyrene itself.

• The Journal of the Korean dental association
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• v.12 no.1
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• pp.29-34
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• 1974

In order to appreciate the school dental services of the primary, middle, and high school and to get the basic data for the university dental service programs in Korea, the author had examined the oral health status of 1,300 freshmen in S University. Then, the followed results were obtained from the calculation and evaluation of DEMT index, DT index, MT index, FT index, DT rate, MT rate, FT rate, debris deposit rate, calculus deposit rate, periodontal disease rate, and abnormal jaw relation rate. 1. DMFT index in the freshmen was higher than that of the Korean youth in the same age. 2. It seems the above result to be appeared from the influence of the intake of the more carbohydrate foods in the freshmen. 3. In the freshmen, MT rate was lower, and FT rate higher than in the Korean youth in the same age. 4. The oral hygiene condition was good in 3.15% of the freshmen. 5. Calculus was not deposited in 8.69% of the freshmen. 6. In 9.69% of the freshmen, the periodontium was healthy. 7. In Korea, the school dental services in the primary, middle, and high schools must be improved. 8. There was the abnormal jaw relation in 12.92% of the freashmen.

• KIPS Transactions on Software and Data Engineering
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• v.3 no.2
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• pp.87-92
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• 2014

In this paper, we present a two-phase activity recognition system using smartphone's accelerometers. To consider the unique temporal pattern of accelerometer data for each activity, our system executes the decision-tree(DT) learning in the first phase, and then, in the second phase, executes the hidden Markov model(HMM) learning based on the sequences of classification results of the first phase classifier. Moreover, to build a robust recognizer for each activity, we trained our system using a large amount of data collected from different users, different positions and orientations of smartphone. Through experiments using 6720 examples collected for 6 different indoor activities, our system showed high performance based on its novel design.

• KEPCO Journal on Electric Power and Energy
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• v.6 no.4
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• pp.405-411
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• 2020

In this paper, we designed the COS MEMS system for sensing the falling detection and explosive noise of fuse link in COS (Cut Out Switch) installing on the power distribution. This system analyzed the failure characteristics and an instantaneous breakdown of power distribution. Therefore, our system strengths the industrial competence and guaranties the stable power supply. In this paper, we applied BLE (Bluetooth Low Energy) technology which is suitable protocol for low data rate, low power consumption and low-cost sensor applications. We experimented with LSM6DSOX which is system-in-module featuring 3 axis digital accelerometer and gyroscope boosting in high-performance mode and enabling always-on low-power features for an optimal motion for the COS fuse holder. Also, we used the MP34DT05-A for gathering an ultra-compact, low power, omnidirectional, digital MEMS microphone built with a capacitive sensing element and an IC interface. The proposed COS MEMS system is developed based on nRF52 SoC (System on Chip), and contained a 3-axis digital accelerometer, a digital microphone, and a SD card. In this paper of experiment steps, we analyzed the performance of COS MEMS system with gathering the accelerometer raw data and the PDM (Pulse Data Modulation) data of MEMS microphone for broadcasting the failure of COS status.

• Journal of Digital Convergence
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• v.16 no.1
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• pp.317-325
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• 2018

A satisfactory ending of the project is crucial for the students to achieve success experience. In this study, we analyze the teams' dismantling before the project deadline. We propose a team dissolution model based on the assumption that the disharmony caused by the members' personality traits is the main reason for the team break up. The Dark Triad and the Communion are introduced to build the model. We simulated the proposed model using an agent-based simulation and analyzed the results. We found that the ratio of owning DT impacts the maximum allowable size of the team and the team's rate of dissolution, but the team has been able to reduce the team's dissolution rate by increasing the team's harmony. We expect that we efficiently used the developed model with the agent-based simulation for the studies related to the dismantling of teams.

• The Korean Journal of Physiology
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• v.2 no.1
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• pp.47-52
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• 1968

Twenty white rabbits anesthetized with nembutal (30 mg/kg) were employed in this experiment. Five of them served as controls; the remaining rabbits as experimental group were subjected to irreversible hemorrhagic shock. Shock was induced by bleeding the animals until mean blood pressure decreased to a level of 50-40 mmHg. This level of pressure was maintained for 3-4 hours, after which the drawn blood was reinfused. The reinfusion of blood caused the elevation of arterial pressure almost the control level for some minutes, after which a gradual and progressive decline of blood pressure became evident. This decline was thought to be the result from irreversible hemorrhagic shock. When mean blood pressure declined to less than 50 mmHg, chest was opened and samples of arterial blood and left ventricular muscle were taken. Left ventricular muscle and blood plasma were analyzed for potassium, sodium, chloride and water content. Blood glucose concentration was determined by Somogyi-Nelson's method. Extracellular and intracellular myocardial water and electrolyte content were calculated on the basis that electrolytes are distributed between plasma water and interstitial water according to Gibbs-Donnan equilibrium. In this calculation extracellular water was substituted for Na space. The findings obtained were as follows: 1. The concentration of blood glucose was 87mg% in the controls and it rose to 222 mg% in shock (P<0.01). 2. Plasma potassium elevated significantly from 3.3 mEq/l in controls to 8.0 mEq/l in shock (P<0.01), while small decreases in sodium (151-146 mEq/l) and chloride (102-96 mEq/l) were observed (P<0.3, P<0.1), 3. The changes of blood water content (83.1-84.3%) and cardiac water content (77.5-78.3 gm/100gm WT) were observed. 4. In control animals myocardial potassium levels which averaged 30.2 mEq/100 gmDT rose significantly to 40.3 mEq/100 gmDT in shock (P<0.01), while moderate decreases in sodium(16.3-14.3 mEq/100 gmDT) were observed in shock. 5. The calculated transmembrane resting potential of left ventricular muscle of control animals averaged 95 mV, while rabbits in shock averaged 77 mV. (P <0.01). The findings of this experiment do not correspond with the conclusions that myocardial depression seems to be the cause of irreversible hemorrhagic shock, because the excitability of heart muscle is elevated. From the point of view that the lowered transmembrane resting potential, the cause of death in terminal stage of irreversible hemorrhagic shock may be ventricular fibrillation. It can't be said, however, that the lowered transmembrane resting potential is responsible for the transition from reversible to irreversible hemorrhagic shock. The marked increase in blood glucose suggested that glycogenolysis in the liver is favorably active in shock.

• Journal of Korean Neurosurgical Society
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• v.29 no.12
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• pp.1563-1569
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• 2000

Objective : Delayed ischemic neurologic deficit(DIND) is one of the major complications following aneurysmal subarachnoid hemorrhage(SAH). However, the correlation between angiographic vasospasm(AV) and DIND after SAH is not precisely known. The authors investigated the timing, incidence, characteristics of DIND, and analyzed correlation between AV and DIND. Patients and Methods : A series of 126 patients with SAH and performed cerebral angiography which, confirmed anterior circulation aneurysm, admitted to between January 1996 to December 1998, were studied retrospectively. A comparative analysis between group 1(G1) in which AV patients presented with DIND, and group 2(G2) patients did not DIND, were done. AV was graded according to location, distribution and degree. Location of vasospasm was classified as basal type(BT), distal type(DT). BT was involved horizontally and include the bilateral carotid systems, proximal middle cerebral artery(MCA) and proximal anterior cerebral artery(ACA). DT was involved vertically and include the MCA branches as they become vertically or posteriorly oriented and the ACA distal to the anterior communicating artery. BT and DT all defined ether as localized type(LT) or combined type(CT). Distribution of vasospasm was classified as type I, type II and type III. Type I represents the involvement of bilateral carotid systems and bilateral anterior cerebral artery, type II was designed as one carotid system without involving anterior cerebral artery, and type III when only some portions of the anterior cerebral artery were involved, bilaterally. Degree of vasospasm was classified as mild(less than 25%), moderate(between 25-50%), severe(greater than 50%), and those were determined by comparing the caliber of the artery in vasospasm to that of the nearest area of apparently normal vessel. Results : The incidence of AV & DIND was 57/126(45.2%), 29/126(23.0%), and timing of DIND was 9 days(${\pm}4.1$) after initial hemorrhage. As for the location, BT was seen in 12 cases(40.0%), DT 11 cases(36.7%) and CT 7 cases (23.3%), respectively. Where as G1, BT was seen 5 cases(18.5%), DT 5 cases(18.5%) and CT 17 cases(63.0%), respectively in G2. CT AV was more correlated with DIND than LT AV(p<0.05). For distribution, type I was seen in 16 cases(59.2%), type II 4 cases(14.8%), type III 7 cases(25.9%) in G1 where as type I was seen in 7 cases(23.3%), type II 10 cases(33.3%), type III 13(43.3%) in G2. Type I AV was well correlated with DIND unlike to type II or type III(p<0.05). As for the degree, mild was seen in 4 cases(14.8%), moderate 14 cases(51.9%), severe 9 cases (33.3%) in G1, and mild 16 cases(18.5%), moderate 11 cases(36.7%) and severe 3 cases(10.0%) in G2. Moderate to severe type AV was well correlated with DIND(p<0.05). Conclusion : These results indicate that it may be possible to predict DIND according to careful analysis of location, distribution, degree of AV in patients with aneurysmal SAH.

• Journal of dental hygiene science
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• v.9 no.5
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• pp.497-506
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• 2009

This study was conducted to estimate the dental caries experience, oral hygiene status and the factors influencing the dental disease in the smoking adolescents and to provide the baseline data for managing smokers efficiently. We recruited 156 smokers(male: 106, female: 50) in middle, high school students in 5 day Non-smoking program in seoul city and 176 non-smokers(male: 64, female: 112) by matching method for considering sex and age from June 1 to August 31 2009. Data on general characteristics, basic oral health care, smoking factors, self-efficiency, control of oral health, oral health promotion behavior, knowledge of oral health were collected by a questionnaire interview. DMFT index, DT index, MT index, FT index, Plaque index, Calculus index were calculated by the oral examination. The results of this study were as follows. 1. Dental clinic visit(p < 0.05), self-perception of oral health status(p < 0.001), oral health concern (p < 0.01) in non-smoker group were significantly higher than that of smoker group. 2. self-efficiency(p<0.05), oral health promotion behavior(p < 0.05) in non-smoker group were significantly higher than that of smoker group. 3. DT index, Plaque index, Calculus index in non-smoker group was significantly lower than that of smoker group(p < 0.0001). 4. The fewer smoke amount, the lower DT index(p < 0.05), Plaque index(p < 0.01), Calculus index(p < 0.001). 5. It was significant correlated among DT index and self-efficiency, oral health promotion behavior, control of oral health. 6. In multiple regression analysis, oral health promotion behavior, Plaque index was proved as a significant factors related with the degree of dental caries experience in smoking adolescents. In other word, the higher oral health promotion behavior, the lower Plaque index, the fewer DT index.