• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.4
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• pp.347-357
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• 2003

This paper describes on the suppression of sea clutter on marine radar display using a cell-averaging CFAR(constant false alarm rate) technique, and on the analysis of radar echo signal data in relation to the estimation of ARPA functions and the detection of the shadow effect in clutter returns. The echo signal was measured using a X -band radar, that is located on the Pukyong National University, with a horizontal beamwidth of $$3.9^{\circ}$$, a vertical beamwidth of $20^{\circ}$, pulsewidth of $0.8 {\mu}s$ and a transmitted peak power of 4 ㎾ The suppression performance of sea clutter was investigated for the probability of false alarm between $l0-^0.25;and; 10^-1.0$. Also the performance of cell averaging CFAR was compared with that of ideal fixed threshold. The motion vectors and trajectory of ships was extracted and the shadow effect in clutter returns was analyzed. The results obtained are summarized as follows；1. The ARPA plotting results and motion vectors for acquired targets extracted by analyzing the echo signal data were displayed on the PC based radar system and the continuous trajectory of ships was tracked in real time. 2. To suppress the sea clutter under noisy environment, a cell averaging CFAR processor having total CFAR window of 47 samples(20+20 reference cells, 3+3 guard cells and the cell under test) was designed. On a particular data set acquired at Suyong Man, Busan, Korea, when the probability of false alarm applied to the designed cell averaging CFAR processor was 10$^{-0}$.75/ the suppression performance of radar clutter was significantly improved. The results obtained suggest that the designed cell averaging CFAR processor was very effective in uniform clutter environments. 3. It is concluded that the cell averaging CF AR may be able to give a considerable improvement in suppression performance of uniform sea clutter compared to the ideal fixed threshold. 4. The effective height of target, that was estimated by analyzing the shadow effect in clutter returns for a number of range bins behind the target as seen from the radar antenna, was approximately 1.2 m and the information for this height can be used to extract the shape parameter of tracked target..

• Radiation Oncology Journal
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• v.18 no.4
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• pp.300-308
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• 2000

Purpose :The aim of this study is to analysis of suwival and recurrence rates of the uterine cervical carcinoma patients whom received the radiation therapy respectively. The prognostic factors, such as Papanicolaou (Pap) smear, carcinoembriogenic antigen (CEA) and squamous cell carcinoma (SCC) antigen has been studied. Methods and Materials : From January 1981 to December 1998, eight-hundred twenty-seven uterine carvical cancer patients were treat with radiation therapy. All of the patients were divided into two groups : the radiation therapy only (S2l patients) group and the postoperative radiation therapy (326 patients) group. The age, treatment modality, clinical stage, histopathology, recurrence, follow-up Pap smears, CEA and SCC antigen were used as parameters for the evaluation. The prognostic factors such as survival and recurrence rates were peformed with the Kaplan-Meier method and the Cox hazard model, respectively. Median rollow-up was 38.6 months. Results :On the radiation therapy only group, 314 patients (60$\%$) achieved complete response (CR), 47 patients (9$\%$) showed local recurrence (LR), 78 patients (15$\%$) developed distant metastasis (DM). On the Postoperative radiation therapy group, showed 276 Patients (85$\%$) CR, 8 Patients (2$\%$) LR, 37 Patients (11$\%$) DM. The 5-year survival and recurrence rates was evaluated for all parameters. The statistically significant factors for the survival rate in univariate analysis were clinical stage (p=0.0001), treatment modality (p=0.0010), recurrence (p=0.0001), Pap smear (p=0.0329), CEA (p=0.0001) and SCC antigen (p=0.0001). Conclusion: This study indicated that after treatment, the follow-up studies of Pap smear, CEA and SCC antigen were significant parameter and prediction factors for the survival and recurrence of the uterine cervical carcinoma.

• Clinical and Experimental Pediatrics
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• v.45 no.5
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• pp.588-595
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• 2002

Purpose : The incidence of obesity has increased in Korea recently. Obesity leads to higher risks of hypertension, hyperlipidemia and insulin resistance. It also leads to risks of respiratory complications. This study was performed to see the effects of obesity on children's pulmonary functions and on developed bronchospasm after exercise loading according to their obesity degrees. Methods : 257 obese children and 150 non-obese children were enrolled. Obese children were divided into 3 groups by the obesity degrees. Pre- and post-exercise loading $FEV_1$(forced expiratory volume at one second), FVC(forced vital capacity) and PEFR(peak expiratory flow rate) were checked in all subjects. The percent predicted values of each parameter was compared according to obesity degrees and the differences between pre-exercise and post-exercise values. Results : The percent predicted value of $FEV_1$, FVC decreased only in the severe obesity group compared with those in the control group. However percent predicted PEFR declined according to obesity degrees. The percent predicted value of $FEV_1$, FVC and PEFR after exercise loading were much lower than those before exercise loading in all groups. Conclusion : As the degree of obesity was higher, the percent predicted value of pulmonary function was lower. And after exercise loading, as the degree of obesity was higher, the reduction of percent predicted value of pulmonary function was larger. Therefore the pulmonary function in obese children must be observed carefully. Further studies on the effects of pulmonary functions in obese children are necessary.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.6
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• pp.1619-1637
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• 2016

With wide distribution of smart phones and development of mobile network, social network service (SNS) is displaying remarkable growth rates. Users build new social relations by sharing their interests, which brings surging growth to the SNS based on the combination between the strength of expanding the place for communication and distribution of smart phones featured with easy portability. This study is designed to understand impact factors of SNS on users in Korea and to conduct empirical research on casual relationship between the factors above and the factors affecting personal information behavior through the privacy protection and self-efficacy. In order to accomplish the objective above, the study presented a research model applied with key variables of the Health Belief Model (HBM) predicting behaviors capable of recognizing and preventing individual diseases in the field of health communication. To perform empirical verification on the research model of this study, a survey was conducted upon college students at N university located in Chungcheongnam-do and K university in rural area, who have experiences using the SNS. Through this survey, a total of 186 samples were collected, and path analysis was performed in order to analyze the relationship between the factors. Based on the findings from the survey, first, variables Perceived probability, Perceived severity, Perceived impairment of the HBM, key factors of personal information protection behavior on the SNS, were found to exhibit negative relationship with self-efficacy, and Perceived probability, Perceived benefit, Perceived impairment were found to exhibit negative relationship with privacy protection. But the above, Perceived severity showed positive relationship with privacy protection, and Perceived benefit and self-efficacy also displayed positive relationship. Second, although self-efficacy, a parameter, showed positive relationship with privacy protection, it demonstrated negative relationship with personal information protection behavior. Lastly, privacy protection exhibited positive relationship with personal information protection behavior. By presenting theoretical model reflected with characteristics of prevention based on these findings above unlike previous studies on personal information protection using technologies threatening personal information, this study is to provide theoretical and operational foundation capable of offering explanations how to predict personal information protection behavior on the SNS in the future.

• Sleep Medicine and Psychophysiology
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• v.5 no.1
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• pp.103-110
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• 1998

Objectives : High co-morbidity of periodic limb movements during sleep(PLMS) and obstructive sleep apnea syndrome(OSAS) is well known and their incidences tend to increase in the elderly. Previous studies have inconsistently rep0l1ed increase or no change of periodic limb movement index(PLMI) by nasal continuous positive airway pressure(CPAP) in OSAS without analyzing possible variables affecting PLMI. We attempted to examine PLMI change evoked during CPAP titration and also factors affecting it in OSAS. Methods : Twenty-nine OSAS patients(M:F=26:3, mean age: $51.6{\pm}10.6\;yrs$) without other sleep disorders except for PLMS were selected, based on the nocturnal (baseline) polysomnograhy. Another night of noctumal polysomnography was performed for CPAP pressure titration. We compared between those two nights PLMI, mean and lowest $SaO_2$, and sleep variables. We also calculated PLMI differences between baseline and CPAP nights, named as delta PLMI (value of CPAP night PLMI minus value of baseline night PLMI). Correlations were calculated between delta PLMI and factors such as age, body mass index, applied CPAP pressure, baseline night values of respiratory disturbance index, mean and lowest $SaO_2$, and sleep parameter differences between baseline and CPAP nights. Results : Decrease of RDI(p<.01) and increase in mean and lowest $SaO_2$ (p<.05, p<.01) were observed during CPAP night. No sleep parameters showed significant change except for the decrease of total stage 1 sleep%(p<.01) during CPAP night. Ten out of 29 patients showed PLMI increase, while the other 19 patients showed either no change(n=14) or even PLMI decrease(n=5) during CPAP night. The 10 patients showing PLMI increase during CPAP night showed a significant positive correlation between delta PLMI and baseline night RDI(p<.05), which meant that PLMI increase was found to be more prominent in higher RDI patients than in lower RDI ones. There were no significant correlations between delta PLMI and other factors in the other 19 patients. Conclusions : We suggest that during the baseline night PLMS would have been underscored and/or masked due to the overlapping of PLMS and apneas/hypopneas or the arousals induced by apneas/hypopneas. Despite its still unknown mechanism, the CPAP application may unmask PLMS and increase PLMI in a subgroup of OSAS patients. It needs to be evaluated further whether the chronic CPAP use sustains the above finding.

• Journal of Sensor Science and Technology
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• v.10 no.1
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• pp.62-70
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• 2001

The ZnSe sample grown by chemical bath deposition (CBD) method were annealed in Ar gas at $45^{\circ}C$. Using extrapolation method of X-ray diffraction pattern, it was found to have zinc blend structure whose lattice parameter $a_o$ was $5.6687\;{\AA}$. From Hall effect, the mobility was likely to be decreased by impurity scattering at temperature range from 10 K to 150 K and by lattice scattering at temperature range from 150 K to 293 K. The band gap given by the transmission edge changed from $2.700{\underline{5}}\;eV$ at 293 K to $2.873{\underline{9}}\;eV$ at 10 K. Comparing photocurrent peak position with transmission edge, we could find that photocurrent peaks due to excition electrons from valence band, ${\Gamma}_8$ and ${\Gamma}_7$ and to conduction band ${\Gamma}_6$ were observed at photocurrent spectrum. From the photocurrent spectra by illumination of polarized light on the ZnSe thin film, we have found that values of spin orbit coupling splitting ${\Delta}so$ is $0.098{\underline{1}}\;eV$. From the PL spectra at 10K, the peaks corresponding to free bound excitons and D-A pair and a broad emission band due to SA is identified. The binding energy of the free excitons are determined to be $0.061{\underline{2}}\;eV$ and the dissipation energy of the donor -bound exciton and acceptor-bound exciton to be $0.017{\underline{2}}\;eV$, $0.031{\underline{0}}\;eV$, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.2
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• pp.119-125
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• 2010

This study was carried out to compare the physicochemical characteristics of Korean traditional wine fermented from proso millet and nuruk at different mixing rate. The alcohol contents of the fermented wine ranged from 12.36 to 13.21%. Two kinds of nuruk, SH and BS nuruks were used. The brix degrees of proso millet wine fermented by SH and BS nuruks were 21.6 and 22.4 $^{\circ}Bx$, respectively. The pH, total acidity, and turbidity the wines fermented by SH and BS nuruks were 3.74 and 3.40, 1.40 and 1.51%, and 0.441 and 0.149, respectively. With increasing the addition amount of proso millet, brix degree, pH, turbidity L-value decreased, and total acidity and avalue increased. Total color difference (${\Delta}Eab$) parameter of the wine fermented by SH nuruk were 4.33, 6.63 and 26.13, and by BS nuruk were 4.08, 5.29 and 10.59 in 30, 70 and 100% addition rates of proso millet. With increasing the addition amount of proso millet, glucose content decreased. The organic acids such as lactic acid and acetic acid were predominantly detected in the fermented wine. Finally, based on sensory evaluations, the wine fermented by SH nuruk showed the best overall quality at 30% addition rate of proso millet.

• Economic and Environmental Geology
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• v.31 no.3
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• pp.185-199
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• 1998

Hydrogeochemical and environmental isotope studies were undertaken for various kinds of water samples collected in 1995-1996 from the Bugok geothermal area. Physicochemical data indicate the occurrence of three distinct groups of natural water: Group I ($Na-S0_4$ type water with high temperatures up to $77^{\circ}C$, occurring from the central part of the geothermal area), Group II (warm $Na-HCO_{3}-SO_{4}$ type water, occurring from peripheral sites), Group III ($Ca-HCO_3$ type water, occurring as surface waters and/or shallow cold groundwaters). The Group I waters are further divided into two SUbtypes: Subgroup Ia and Subgroup lb. The general order of increasing degrees of hydrogeochemical evolution (due to the degrees of water-rock interaction) is: Group III$\rightarrow$Group II$\rightarrow$Group I. The Group II and III waters show smaller degrees of interaction with rocks (largely calcite and Na-plagioclase), whereas the Group I waters record the stronger interaction with plagioclase, K-feldspar, mica, chlorite and pyrite. The concentration and sulfur isotope composition of dissolved sulfate appear as a key parameter to understand the origin and evolution of geothermal waters. The sulfate was derived not only from oxidation of sedimentary pyrites in surrounding rocks (especially for the Subgroup Ib waters) but also from magmatic hydrothermal pyrites occurring in restricted fracture channels which extend down to a deep geothermal reservoir (typically for the Subgroup Ia waters). It is shown that the applicability of alkaliion geothermometer calculations for these waters is hampered by several processes (especially the mixing with Mg-rich near-surface waters) that modify the chemical composition. However, the multi-component mineral/water equilibria calculation and available fluid inclusion data indicate that geothermal waters of the Bugok area reach temperatures around $125^{\circ}C$ at deep geothermal reservoir (possibly a cooling pluton). Environmental isotope data (oxygen-18, deuterium and tritium) indicate the origin of all groups of waters from diverse meteoric waters. The Subgroup Ia waters are typically lower in O-H isotope values and tritium content, indicating their derivation from distinct meteoric waters. Combined with tritium isotope data, the Subgroup Ia waters likely represent the older (at least 45 years old) meteoric waters circuated down to the deep geothermal reservoir and record the lesser degrees of mixing with near-surface waters. We propose a model for the genesis and evolution of sulfate-rich geothermal waters.

• Journal of Korean Orthopaedic Sports Medicine
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• v.1 no.1
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• pp.31-36
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• 2002

Purpose : ACL (anterior cruciate ligament) reconstruction using achilles allograft was done for whom ACL injured person in recreational sports activity. The purpose of this study was to evaluate the clinical results and return to their sports activity in these patients. Materials and Methods : ACL injured 56 amateur athletes who had experienced sports 3 times a week more than 5 years, reconstructed with Achilles allograft, and it was analyzed subjective and objective parameter, Tegner scoring, Telos stress arthrometer, Lysholm Knee Scoring System and modified Feagin scoring system. The average age was 25 years old (range: 18$\~$49), the average follow up period was 15 months (range: 12$\~$19). Morbid sports were football (29 cases), basket ball (14 cases), badminton (5 cases), tennis (3 cases), squash (2 cases) and otherwise (3 cases). Result : The mean Lysholm Knee Scoring System was improved to 88.2 from 60. Telos arthrometer in anterior stress test revealed 2.3 mm improved from 7.1 mm. The modified Feagin scoring system showed 50 cases (89$\%$) with excellent and good results. We had obtained 12 cases (21$\%$) of Tegner score VI, 32 cases (57$\%$) of score V, 20 cases (35%$\%$ of score IV, 3 (5.3$\%$) cases of score III. Conclusions : Reconstruction of anterior cruciate ligaments can restore stability sufficient to allow sports activity in ACL injured patients, but it’s difficult to achieve 'normal' sports activity. So we will have to solve the reasons of this dissatisfaction at furthermore.

• Journal of Intelligence and Information Systems
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• v.18 no.2
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• pp.157-175
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• 2012

It is difficult to evaluate the performance of process innovation of e-procurement which has large scale and complex processes. The existing evaluation methods for measuring the effects of process innovation have been mainly done with statistically quantitative methods by analyzing operational data or with qualitative methods by conducting surveys and interviews. However, these methods have some limitations to evaluate the effects because the performance evaluation of e-procurement process innovation should consider the interactions among participants who are active either directly or indirectly through the processes. This study considers the e-procurement process as a complex system and develops a simulation model based on MAS(Multi-Agent System) to evaluate the effects of e-procurement process innovation. Multi-agent based simulation allows observing interaction patterns of objects in virtual world through relationship among objects and their behavioral mechanism. Agent-based simulation is suitable especially for complex business problems. In this study, we used Netlogo Version 4.1.3 as a MAS simulation tool which was developed in Northwestern University. To do this, we developed a interaction model of agents in MAS environment. We defined process agents and task agents, and assigned their behavioral characteristics. The developed simulation model was applied to G2B system (KONEPS: Korea ON-line E-Procurement System) of Public Procurement Service (PPS) in Korea and used to evaluate the innovation effects of the G2B system. KONEPS is a successfully established e-procurement system started in the year 2002. KONEPS is a representative e-Procurement system which integrates characteristics of e-commerce into government for business procurement activities. KONEPS deserves the international recognition considering the annual transaction volume of 56 billion dollars, daily exchanges of electronic documents, users consisted of 121,000 suppliers and 37,000 public organizations, and the 4.5 billion dollars of cost saving. For the simulation, we analyzed the e-procurement of process of KONEPS into eight sub processes such as 'process 1: search products and acquisition of proposal', 'process 2 : review the methods of contracts and item features', 'process 3 : a notice of bid', 'process 4 : registration and confirmation of qualification', 'process 5 : bidding', 'process 6 : a screening test', 'process 7 : contracts', and 'process 8 : invoice and payment'. For the parameter settings of the agents behavior, we collected some data from the transactional database of PPS and some information by conducting a survey. The used data for the simulation are 'participants (government organizations, local government organizations and public institutions)', 'the number of bidding per year', 'the number of total contracts', 'the number of shopping mall transactions', 'the rate of contracts between bidding and shopping mall', 'the successful bidding ratio', and the estimated time for each process. The comparison was done for the difference of time consumption between 'before the innovation (As-was)' and 'after the innovation (As-is).' The results showed that there were productivity improvements in every eight sub processes. The decrease ratio of 'average number of task processing' was 92.7% and the decrease ratio of 'average time of task processing' was 95.4% in entire processes when we use G2B system comparing to the conventional method. Also, this study found that the process innovation effect will be enhanced if the task process related to the 'contract' can be improved. This study shows the usability and possibility of using MAS in process innovation evaluation and its modeling.