• Journal of Communications and Networks
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• v.11 no.2
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• pp.104-114
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• 2009

In this paper, a technique is proposed that enables secondary users to evaluate channel availability in cognitive radio networks. Here, secondary users estimate the utilization of channels via predicting the traffic pattern of primary user, and select a proper channel for radio transmission. The proposed technique reduces the channel switching rate of secondary users (the rate of switching from one channel to another) and the interference on primary users, while maintaining a reasonable call blocking rate of secondary users.

• Journal of Preventive Medicine and Public Health
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• v.17 no.1
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• pp.31-36
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• 1984

In order to know about the utilization of health subcenter in a Korean rural community, a study was carried out through analyzing the records on the outpatients in Su-Dong Health Subcenter during 5 years from 1978 to 1982, and the following results were obtained. 1. The annual utilization rate of health subcenter of Su-Dong Myun showed decreasing tendency such as 946.6 in 1978, 886.4 in 1979, 736.5 in 1980, 708.3 in 1981 and 609.1 in 1982 per 1,000 people. 2. In terms of annual utilization rate of health subcenter by sex, utilization rate of female was higher than that of male such as in 1978 (male 908.6, female 986.3), 1979 (male 819.2, female 956.7) and 1981 (male 686.0, female 731.5) except 1980(male 790.0, female 683.3) and 1982(male 632.7, female 585.0). 3. Every year the 5 major diseases of the new patients cared in health subcenter were the same as follows; Diseases of the Respiratory System, Diseases of the Digestive System, Diseases of the Skin and Subcutaneous Tissue, Accident Poisoning and Violence, and Diseases of the Nervous System and Sensory Organ. 4. In terms of annual utilization rate of health subcenter by age, utilization rate of $0{\sim}4$ year group was highest every year such as 3,666.0 in 1978, 3,232.5 in 1979, 2,819.0 in 1980, 2,361.4 in 1981 and 2408.7 in 1982 per 1,000 people. 5. The average visiting times per case to health subcenter were not much different every year such as 1.75 times in 1978, 1.79 times in 1979, 1.69 times in 1980, 1.79 times in 1981, and 1.80 times in 1982. 6. The monthly utilization rates per 1,000 people of health subcenter had two peaks in February(40.9 in 1980 and 86.4 in 1981) and July(84.6 in 1980 and 72.1 in 1981) except 1982. 7. The distribution of new patients by the source of medical fee payment was follows; community health organization member 86.9%, medicaid program 6.5%, and medical insurance 6.6% in 1980 and community health organization member 76.8%, medicaid program 11.4%, and medical insurance 11.8% in 1981 and community health organization member 78.2%, medicaid program 14.8% and medical insurance 13.2% in 1982.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.9A
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• pp.1359-1371
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• 1999

In this paper, we propose an efficient explicit rate (ER) feedback switch algorithm for available bit rate (ABR) flow control. In order to improve the disadvantages of existing ER feedback switch algorithms with congestion avoidance, the proposed scheme adjusts the target utilization dynamically according to the queue length and its growth rate. also, we investigate the performance of the proposed switch algorithm and compare it with ERICA and NIST switches using simulation. Simulation results show that the proposed switch algorithm can control the cell emission rate of a source rapidly according to variations of available link bandwidth by using dynamic adaptation of target utilization. It also exhibits a better performance than the existing ER feedback switches in terms of queue length and link utilization.

• Ocean and Polar Research
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• v.38 no.3
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• pp.195-207
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• 2016

Because the high latitude region in the North Pacific is characterized by high primary production in the surface water enriched with nutrients, it is important to understand the variation of surface water productivity and associated nutrient variability in terms of global carbon cycle. Surface water productivity change or its related nutrient utilization rate during the Northern Hemisphere Glaciation (NHG; ca. 2.73 Ma) has been reported, but little is known about such circumstances under gradual climate cooling since the NHG. Bulk nitrogen isotope (${\delta}^{15}N_{bulk}$) of sedimentary organic matter has been used for the reconstruction of nutrient utilization rate in the surface water. However, sedimentary organic matter experiences diagenesis incessantly during sinking through the water column and after burial within the sediments. Thus, in this study we examine the degree of nitrate utilization rate during the early Pleistocene (2.4-1.25 Ma) since the NHG, using the diatom-bound nitrogen isotope (${\delta}^{15}N_{db}$), which is known to be little influenced by diagenesis, from Site U1343 in the Bering slope area. ${\delta}^{15}N_{db}$ values range from ~0.5 to 5.5‰, which is lower than ${\delta}^{15}N_{bulk}$ values, but they vary with larger amplitude. Variation patterns between ${\delta}^{15}N_{db}$ values and biogenic opal concentration are generally consistent, which indicates that the nitrate utilization rate is closely related to opal productivity change in the surface water. A positive correlation between opal productivity and nitrate utilization rate was observed, which is different from the other high latitude regions in the North Pacific. The main reason for this contrasting relationship is that the primary production in the surface water at Site U1343 is influenced mostly by the degree of sea ice formation. Still, although concerns about diagenetic alteration have been avoided by using ${\delta}^{15}N_{db}$, the effects of the preservation state of biogenic opal and the species-dependent isotopic fractionation on ${\delta}^{15}N_{db}$ should be assessed in the future studies.

• Journal of agricultural medicine and community health
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• v.29 no.1
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• pp.195-206
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• 2004

Objectives: This study was conducted to investigate the patterns of medical utilization and factors affecting medical utilization of population living in islands of province of ChungCheongNam-Do. Methods: Demographic and socioeconomic state, medical utilization of 447 persons were surveyed from Sept. 9th to Sept. 18th, 2002. Results: In elder age group and lower educational group, the rate of medical utilization was high. As subjective health states get lower, the group used medical institution more(p<0.05). The group having more number of chronic diseases showed more medical utilization. And the group who needs 2 to 3 hours to reach to the medical institution showed high medical utilization(p<0.05). The factors having negative effect on using medical institution were economic concern and lack of proper clinic in the neighborhood. Conclusions: The lower economic level and the insufficiency of medical facilities on islands affect the utilization rate negatively. More accessible and effective medical systems for these population are expected.

• Health Policy and Management
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• v.2 no.1
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• pp.147-166
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• 1992

The purpose of this study is to analyze the effects of the health center hospital on the health service utilization pattern of the rural population in a county. Two field studies had been conducted in Yonchon County, Kyunggi Province, on February 1989 and on August 1991 before and after the establishment of the Yonchon health center hospital. This study revealed that Yonchon health center hospital occupied 7.3% of total outpatient visits and 16.8% of hospitalization of the county population and the self-sufficient rate of the outpatient visit and hospitalization of Yonchon County between two field studies increased by 1.7% and 20.9% each. Yonchon health center hospital contributed to the growth of the public health sector but it weakened the role of health sub-centers. For the efficient health service utilization of the population in that County, more investment to health center hospital would be needed and the primary health activities of the health subcenter should be enforced.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.3
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• pp.1113-1135
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• 2018

Existing trust evaluation models for wireless sensor networks can accurately and objectively evaluate trust value of nodes, but the nodes' energy saving problem was ignored. Especially when there are a few malicious nodes in a network, the overall trust value calculation for all nodes would waste lots of energy. Beside that, the network failure caused by nodes death was also not considered. In this paper, we proposed a method for avoiding energy hole which applied trust evaluation models and a trust evaluation method based on information entropy, so as to achieve the purpose of improving nodes utilization. Simulation results show that the proposed method can effectively improve nodes utilization, and it has reasonable detection rate and lower false alert rate compared to other classical methods.

• Journal of the Korea Safety Management & Science
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• v.4 no.4
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• pp.129-136
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• 2002

Utilization rate for the restrictive gate and required time and walking distance to board are to be a measure for the gate management and passenger's convenience estimation. So, the main purpose of the gate management are maximization of utilization rate and increment of airport terminal user's convenience through the efficient gate management. This study intends to maximize the utilization rate on usable gates and minimize the passenger's working distance in terminal by concerning about layout, terminal configuration, local passenger of the airport and formulate the gate assignment problem with integer linear programming problem. Then we obtained solution using optimization software LINGO and analyzed that maximize the number of assignment flights and minimize the passenger's walking distance.

• Journal of Preventive Medicine and Public Health
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• v.19 no.1 s.19
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• pp.137-145
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• 1986

A Nationwide health care utilization survey was conducted from March 11 to September 19, 1985 to assess the level of illness and the magnitude of medical care utilization. A probability sample of 15,427 persons was taken from 180 Enumerated Districts designated by the Economic Planning Board. Of those 4,500 housewives were proxy respondents. A interview was conducted with pre-tested questionnaire schedule which was recorded by well trained interviewers. Age and sex compositions of the study population were similar to those of general population structure in 1985. The major findings of this survey are as follows : 1) A total of 64.5% of the study population lived in city area and 35.5% lived in county area. 2) While no difference was observed in interview rate between city and county area, it showed statistically significant difference in the medical security program coverage rate between the two areas(44.7% and 37.1%, respectively) 3) Morbidity rate was 79 per 1,000 persons during the two week periods. There was difference in age and sex adjusted morbidity rates between city and county area. Furthermore morbidity rates by the status of the program were significantly difference between the two areas. 4) Average ambulatory care utilization rate was 7.2 visits per person per year and average admission rate was 1.8 per 100 persons per year. There was significant difference in average ambulatory care utilization rate by the program. but no significant difference in medical utilization rate between city and country area. 5) The major symptoms of the perceived illness was the respiratory system(44.1%). 6) A total of 50.4% of the perceived illness among the covered group by the program were treated at the hospital and clinics, but those who are not covered used primarily drug stores(61.3%).

• Journal of Preventive Medicine and Public Health
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• v.30 no.4 s.59
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• pp.764-778
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• 1997

To find the medical insurance utilization of workers when suffering from low back pain, an analysis was made toward the data of medical insurance benefits matched with the general characteristics of 10,183 workers, who were registered continuously from 1993 to 1995 at a medical insurance cooperation for industrial workers. The results were as follows; 1. The period prevalence of the medical insurance utilization for low back pain for 3 years from 1993 to 1995 was calculated as 17.1% for male workers and 19.4% for female workers. Most common cause of utilization was other dorsopathies including the herniation of lumbar discs. 2. The utilization rate increased significantly as the present age and the age joining the company got older(p<0.001). As the duration of employment got longer, the utilization rate of the male showed the tendency to increase and that of the female increased significantly(p<0.05). Among male workers employed at cement and concrete manufacturing companies showed higher utilization rate and among female laborers showed significantly higher utilization rate than clerical workers(p<0.01). 3. Annual utilization rate for low back pain didn't show any difference, but the portion of other dorsopathies among cause of utilization showed the tendency to increase from 1993 to 1995. 4. The mean number of claims for outpatient medical care for low back pain differed significantly by age, working duration, type of industries, income level(p<0.05), and the mean of total visiting days for care of low back pain differed significantly by working duration. In conclusion, considering the fact that the medical insurance utilization for low back pain increased annually and other dorsopathies including the herniation of dorsopathies were increasing, an effective preventive or management program for low back pain toward worker employed at industries were required.