• Journal of Internet Computing and Services
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• v.12 no.4
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• pp.35-43
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• 2011

Cognitive Radio (CR) ad hoc network is highly considered as one of promising future ad hoc networks, which enables opportunistic access to under-utilized licensed spectrum. Similarly to other CR networks, the spectrum sensing is a prerequisite in CR ad hoc network. Collaborative spectrum sensing can help increasing sensing performance. For such an infrastructureless network, however the coordination for the sensing collaboration is really complicated due to the lack of a central controller. In this paper, we propose a novel collaborative spectrum sensing scheme in which the final decision is made by the node with the highest data reliability based on a sequential Dempster Shafer theory. The collaboration of sensing data is also executed by the proposed contention-aware reporting mechanism which utilizes the sensing data reliability order for broadcasting spectrum sensing result. The proposed method reduces the collecting time and the overhead of the control channel due to the efficiency of the ordered sequential combination while keeping the same sensing performance in comparison with the conventional cooperative centralized spectrum sensing scheme.

• Research in Plant Disease
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• v.17 no.3
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• pp.381-385
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• 2011

Effects of temperatures, relative humidity, pH, and dry periods on conidial germination of Alternaria dauci were evaluated under in vitro conditions. Conidial germination was accelerated at over 95% relative humidity in $15^{\circ}C$ to $25^{\circ}C$ condition. Conidial germination was rapidly reduced at 5 regardless of relative humidity conditions. More than 50% of the conidial germination were initiated within 2 h at $25^{\circ}C$ through pH 5 to 7. The highest conidial germination of A. dauci was on 0.2% of carrot leaf extract. Conidia could survive longer than 12 h, even though its germination decreased. After a 12 h dry period, around 10% of conidia revived and germinated when conidia were hydrated again. These results could be used as the useful information on conidial germination of A. dauci and ecology of Alternaria leaf blight.

• Journal of Preventive Medicine and Public Health
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• v.31 no.3 s.62
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• pp.516-539
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• 1998

The objective of this study is to identify the difference in attitude toward medical care between patients who visited a university hospital or an oriental medical hospital of oriental medical college, and physicians who engaged in the same hospitals. The subjects of this study were 397 cases who agreed to respond the prepared questionnaire, including 288 patients(146 university hospital utilizers and 142 utilzers for an oriental medical hospital) and 109 physicians(76 physicians and 33 oriental medical doctors). The attitude toward medical care was measured by the structured questionnaire developed for this study, which had high validity and reliability according to factor analysis, item discriminant validity, and Cronbach's $\alpha$ coefficients. On the criteria of mean value of care and cure score, the attitude toward medical care was classified into 4 groups encompassing a group with dependent attitude on medical care, a group with skeptical attitude toward it, a group with cure-oriented attitude, and a group with care-preferred attitude. The results of chi-square test, discriminant analysis, and logistic regression analysis were as follows; patients who visited a univisity hospital, patients who visited an oriental hospital, physicians, and oriental medical doctors included in the group with dependent attitude, the group with cure-oriented attitude, the group with skeptical attitude, and the group with care-preferred attitude, retrospectively. Among the subdomains of care and cure domains, which classified in reference to the result of factor analysis on pilot study, those that patients ranked more importantly than physicians were 'the importance of medical equipment for diagnosis and treatment', 'authority of physician, 'aggressiveness of treatment', 'information giving', 'personal interest' in the case of western medicine. In the case of oriental medicine, those were 'the importance of equipment for diagnosis and treatment', 'aggressiveness of treatment', 'amenities and accessibility', 'coordination of medical staff'. Both physicans and patients put the subdomain, 'physicians' medical knowledge and skillfulness' on the highest rank. The differences in ranking the important attributes of medical care between patients and physicians were apparent in the area of an 'importance of medical equipment for diagnosis and treatment' and so on. It meant that patient had over-expectation on medical care and suggested that the policy on demanad side such as the developement and dissemination of an evidence-based recommendation protocol for health care consumers might be important in Korea. In addition, regarding the attitude of physicians, during the medical education and training it may be neccessary to emphasize the aspect of 'care' of medical care rather than 'cure'. In planning on heath care delivery system, it should be considered that there is a difference in the attitude toward medical care between western medicine and oriental medicine as well as between health care providers and consumers. We expect that more valid measurement tool be developed in this area, which may be major limitation of this study and that this kind of research be expanded into the non-academic settings.

• Journal of Society of Preventive Korean Medicine
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• v.4 no.2
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• pp.1-24
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• 2000

This study was conducted to examine utilization patterns and determinants of oriental medical services. Data were collected from 545 residents in Taegu city The results of this study are summarized as follows 1) 37.8% of subjects used oriental medical services in the past year. Especially, the female, the ages of 50 and 60 over, the single. low-educated. high-income class, white-collar class, medical insured tended to use more oriental medical services than another groups. 2) 46.7% of users of oriental medical services reported that number of visits in the past year was 2 - 5 times 37 1% of them was 1 times, and 4.5% over 10 times. 3) According to the reasons to choose the oriental medical facilities, most was 'on their own judgement'(48.8%) and 'by the advice of relatives and friends'(42.0%) Regarding to the objectives of using oriental medicine, 68.3% was 'treatment', 31.7% 'health counselling and promotion'. And among diseases of users, diseases of musculo-skeletal system was the highest(54.5%). 4) 57.9% of oriental medical services users had experience of utilizing western medicine on the same diseases. Among peoples with experiencing western medicine on the same diseases. 54.4% received oriental medical services 'in addition to western medicine', 45.6%'in place of western medicine 'And 41.2% of using both services reported that they had difficulty in deciding to choose the type of services -oriental medical services or western medicine-for their diseases. 37.3% of them answered that 'providing relevant information' was the most desirable measure to solve this problem, 27.3% 'establishment of effective referral system between oriental and western medical facilities '23.6% 'cooperative medical treatment systems in the same facilities', 11.8%'integration of oriental medicine into western medicine 5) According to the satisfaction level with each items of oriental medical services, the respondents had positive views on efficacy, kindness, and side-effects. They, however, had negative view on the cost of oriental medical services. 6) In regarding to the priority of improvement of oriental medical system,'expansion of insurance benefit package 'ranked first. 'expansion of insurance benefit Package 'ranked second, 'improvement of scientific methods and diagnostic technique 'third, and 'safety of herbal medicine' fourth in order. 7) The significant factors influencing the utilization of oriental medical services were kindness of oriental medical practitioners, efficacy , travel time, age To be brief, utilization rate of oriental medical services in urban area generally tends to be high. There, however, have been various barriers to limit oriental medical services, such as incomplete benefit package of oriental medical insurance and lack of coordination and referral system between oriental and western medical services, lack of scientific diagnostic procedures, high price etc . For the development of oriental medical services, Much attention to remove these limiting factors should be placed. In addition, kindness of oriental medical practitioners , which is expected to be more important factor in the consumer - focused health care environment than ever, should be kept high consistently. Since this study was conducted for specific residents of an urban city. further research including more sampling in different urban areas should be required to generalize the results of the study.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.5
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• pp.462-472
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• 2017

Sunken vessels on major fairways can cause many problems in terms of maritime safety and the marine environment. In order to prevent secondary marine pollution accidents caused by sunken vessels, information on sunken vessels has been collected, a risk assessment has been conducted, and the relevant vessels are being managed according to the results of each assessment. However, there is still a demand for improvements. The most important of the improvement plans is a paradigm shift. In other words, the management of sunken vessels needs to be transformed according to a new paradigm to manage all sunken vessels within three years from the time of sinking. Legislative improvements are also needed for the reporting system for sunken vessels, risk assessment tools, the implementation of risk mitigation measures, and criteria for the implementation cost of risk mitigation measures. In addition, close coordination between marine pollution response and sunken vessel management efforts is needed. As the division of duties between the Korea Coast Guard and the Ministry of Oceans and Fisheries is vague, collaboration between the two ministries is required. Close collaboration is also needed between the departments of navigation safety management and sunken vessel management. Therefore, it is necessary to more clearly establish the relationship between the two systems and create a synergy effect between the two administrative operations using the results of the risk assessment in the Marine Environment Management Act to determine the navigational risk posed by obstacles with regard to the Maritime Safety Act.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.4
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• pp.293-299
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• 2016

The chemical properties of paddy fields in Gangwon province were monitored every 4 years from 2003 to 2015 in order to provide basic information for soil fertility management of paddy fields. In 2015, the soil chemical properties of paddy fields were 5.9 in pH, $22g\;kg^{-1}$ in organic matter (OM), and $123mg\;kg^{-1}$ in available (Avail.) phosphate $P_2O_5$. Exchangeable (Exch.) potassium (K), calcium (Ca) and magnesium (Mg) were 0.39, 4.8 and $0.9cmolc\;kg^{-1}$, respectively, and Avail. $SiO_2$ was $170mg\;kg^{-1}$. In the long-term analysis, the contents of Avail. $SiO_2$, Exch. K and pH of paddy soils showed increasing tendency. However, Avail. $P_2O_5$, Exch. Ca and Mg tended to decrease, and there were no significant changes in the contents of OM. Soil OM, Avail. $P_2O_5$ and $SiO_2$ were not different among the different topographical sampling sites. However, the mean value of Exch. K and Ca were different among the different topographical sampling sites, and exceeded optimal values in the fluvio-marine plains. Different soil texture resulted in different soil pH, while no difference for OM, Avail. $P_2O_5$ and $SiO_2$. Paddy soil samples within appropriate pH range increased from 65% in 2003 to 77% in 2007, 68% in 2011, and 71% in 2015. In case of Avail. $SiO_2$, soil samples within appropriate range increased from 20% in 2003, to 37% in 2007, 29% in 2011, and 45% in 2015. Meanwhile, Cd and Pb were distributed to less than 5% of soil pollution standards. Cu, As and Zn were distributed to less than 10%, 15% and 20%, respectively. Therefore, paddy soil in Gangwon Province was judged to be safe. As a result, paddy fields with more or less in nutrient level need to be fertilized based on the soil analysis. And the application of silicate fertilizer is strongly recommended to those of paddy fields in need. In addition, soil management including the cultivation of green manure crop or application of rice straw is necessary to increase the organic matter content of paddy soil.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.8 no.1
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• pp.101-112
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• 1997

The purpose of this study was to examine usefulness of KEDI-Individual Basic Learning Skills Test as a diagnostic tool of learning disorders(LD). Learning disorder group consisted of two subgroups, verbal learning disorder group(VLD, n＝34) and nonverbal learning disorder group(NVLD, n＝14). Comparison group consisted of Dysthymia Disorder subgroup(n＝11) and Normal subgroup(n＝20). Performance of intelligence test and achievement test was examined in all 4 subgroups. In KEDI-WISC, VLD subgroup revealed primary problems in vocabulary, information and verbal-auditory attention test. NVLD group revealed primary problems in almost all performance tests such as visual acuity, psycho-motor coordination speed and visual-spatial organizations ability subtest. In KEDI-Individual Basic Learning Test, VLD group revealed primary problems in phonological coding process, word recognition and mathematics. For successful classification of LD children, the importance of achievement test and intelligence test was discussed by discriminant analysis and factor analysis. The results indicate that KEDI-Individual Basic Learning Skills is of considerable usefulness in diagnosing LD, but must be used in subtests, and additional tests must be conducted for thorough exploration of LD.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.10 s.352
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• pp.79-89
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• 2006

TCP is the most widely used transport protocol in Internet applications that guarantees a reliable data transfer. But, in the wireless multi-hop networks, TCP performance is degraded because it is designed for wired networks. The main reasons of TCP performance degradation are contention for wireless medium at the MAC layer, hidden terminal problem, exposed terminal problem, packet losses in the link layer, unfairness problem, reordering problem caused by path disconnection, bandwidth waste caused by exponential backoff of retransmission timer due to node's mobility and so on. Specially, in the mobile ad-hoc networks, discrepancy between a station's transmission range and interference range produces hidden terminal problem that decreases TCP performance greatly by limiting simultaneous transmission at a time. In this paper, we propose a new MAC algorithm for mobile ad-hoc networks to solve the problem that a node can not transmit and just increase CW by hidden terminal. In the IEEE 802.11 MAC DCF, a node increases CW exponentially when it fails to transmit, but the proposed algorithm, changes CW adaptively according to the reason of failure so we get a TCP performance enhancement. We show by ns-2 simulation that the proposed algorithm enhances the TCP performance by fairly distributing the transmission opportunity to the failed nodes by hidden terminal problems.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.46 no.2
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• pp.61-71
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• 2009

In this paper, we propose a low-cost and compact motion capture system which enables to play motion games in PS2(Play Station 2). Recently, motion capture systems which are being used as a part in film producing and making games are too expensive and enormous systems. Now days, motion games using common USB camera are slow and have two-dimension recognition. But PSD sensor has a few good points, such as fast and low-cost. In recently year, 3D motion capture systems using 2D PSD (Position Sensitive Detector) optic sensor for motion capturing have been developed. One is Multi-PSD motion capture system applying stereo vision and another is Single-PSD motion capture system applying optical theory ship. But there are some problems to apply them to motion games. The Multi-PSD is high-cost and complicated because of using two more PSD Camera. It is so difficult to make markers having omni-direction equal intensity in Single-PSD. In this research, we propose a new theory that solves aforementioned problems. It can measure 3D coordination if separated two marker's intensity is equal to. We made a system based on this theory and experimented for performance capability. As a result, we were able to develop a motion capture system which is a single, low-cost, fast, compact, wide-angle and an adaptable motion games. The developed system is expected to be useful in animation, movies and games.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.3
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• pp.167-173
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• 2013

Purpose: The aim of this study is to analyze the series of panoramic radiograph of implant patients using the system to measure peri-implant crestal bone loss according to the elapsed time from fixture installation time to more than three years. Methods: Choose 10 patients having 45 implant fixtures installed, which have series of panoramic radiograph in the period to be analyzed by the system. Then, calculated the crestal bone depth and statistics and selected the implant in concerned by clicking the implant of image shown on the monitor by the implemented pattern recognition system. Then, the system recognized the x, y coordination of the implant and peri-implant alveolar crest, and calculated the distance between the approximated line of implant fixture and alveolar crest. By applying pattern recognition to periodic panoramic radiographs, we attained the results and made a comparison with the results of preceded articles concerning peri-implant marginal bone loss. Analyzing peri-implant crestal bone loss in a regression analysis periodic filmed panoramic radiograph, logarithmic approximation had highest $R^2$ value, and the equation is as shown below. $y=0.245Logx{\pm}0.42$, $R^2=0.53$, unit: month (x), mm (y) Results: Panoramic radiograph is a more wide-scoped view compared with the periapical radiograph in the same resolution. Therefore, there was not enough information in the radiograph in local area. Anterior portion of many radiographs was out of the focal trough and blurred precluding the accurate recognition by the system, and many implants were overlapped with the adjacent structures, in which the alveolar crest was impossible to find. Conclusion: Considering the earlier objective and error, we expect better results from an analysis of periapical radiograph than panoramic radiograph. Implementing additional function, we expect high extensibility of pattern recognition system as a diagnostic tool to evaluate implant-bone integration, calculate length from fixture to inferior alveolar nerve, and from fixture to base of the maxillary sinus.