• Parasites, Hosts and Diseases
• /
• v.32 no.1
• /
• pp.57-60
• /
• 1994

In order to search the fate of Thelohonellus kitauei spores the extrusion rates of the polar filaments were monitored in uipo chronologically. Preserved spores suspended with various solutions at $-70^{\circ}C$ showed almost the same vigorous pattern as early freezing stages up to 1,750 days after initial preservation. It revealed that the vlabllltles of some spores suspended with 0.45% and 0.9% NaCl solutions and distilled water at $5^{\circ}C$ continued for 1,628 days, 1,614 days and 1,721 days, respectively. And, the life spans of some spores in the previous solutions added with antibiotics at $5^{\circ}C$ were 1,628 days, 1,614 days and 1,714 days, respectively. Key words: TheLohanellus kitnuei, spore, extrusion rate of polar filament, life span

• Tribology and Lubricants
• /
• v.16 no.1
• /
• pp.39-45
• /
• 2000

In this paper, the effects of shaft and bearing flexibilities are investigated for the accurate modeling of a shaft-bearing system supported by ball bearings. Generally, rolling bearings are modeled by simple rigid pin-joint in the mechanical design. However, they can no longer be modeled by ideal boundary conditions in the advanced applications because the rigid pin-joint model cannot satisfy the current trends of mechanical design decreasing mass and reducing volume. Consequently the flexible support model of ball bearing is investigated using the static analysis module developed by A .B. Jones and T. A. Harris. A simple two-bearing system, supported by two deep groove ball bearings and radially loaded on the shaft midway between the bearings, is utilized to validate the coupled model of shaft-bearing system. Numerical computations using the model indicate that the shaft span length, locating/floating bearing arrangements and applied bearing size are significant factors in determining the mechanical behaviors. The flexible support model of ball bearing can be escaped to over-estimate in the bearing fatigue life. The proposed simple design formulation obtained by numerical simulations can approximately predict a rate of bearing life reduction as a function of shaft span length/shaft diameter (L/d).

• Journal of Korea Society of Industrial Information Systems
• /
• v.25 no.1
• /
• pp.1-11
• /
• 2020

Wireless sensor networks consist of a large number of tiny sensor nodes which have limited battery life. In order to maximize the network life span, we propose an optimal transmission radius, R, for control messages. We analyze the transmission radius as a function of the energy consumption of cluster head nodes and the energy consumption of member nodes to find the optimal value of R. In simulations we apply our proposed optimization of transmission range to LEACH-based single-hop and multi-hop networks to show that our proposed scheme outperforms other existing routing algorithms in terms of network life span.

• Korea journal of population studies
• /
• v.14 no.1
• /
• pp.35-46
• /
• 1991

Improvements in various health indices have been ushered in, along with soaring economic growth in the last few decades in Korea. Life span of Koreans at present stands at somewhere around age of seventies. It seems of worth to elucidate some facets of health profile of historic Koreans during Yi dynasty encompassing about five hundreds years between the 14th and 19th century. Datas on health of historic Koreans are meager with exception for sovereigns for whom royal archives have been preserved intact through centuries. Though the health environments for monarchs are, no doubt, incomparable to that of the grassroot levels during the same period, health profile of monarchs would facilitate to assess health indices for historic Koreans during Yi dynasty. Arithmetic average of life span of 25 consecutive Kings(omitted the last two Kings under Japanese control) is 44.6 years of age 81 year old for King Yongjo and 16 year old for King Danjong, representing two extremes. The principal causes of death are septicemia, subsequent to infections of soft tissue and ether organs(8 in number, one-thirds of all). Secondly, both epidemic disease and vascular accidents caused deaths of three Kings each. Two kings succumbed to diabets and one suicide. The causes for the remainder, eight kings are hardly ciarified. The monarchs who contributed in establishment of new Yi dynasty with highspirited and disciplined survied beyond their fifties and sixties. In contrast, those who reigned during mid - era of the dynasty at its culmination succumbed to death in their young adulthood, most likely due to their indulgence in court life.

• Asian-Australasian Journal of Animal Sciences
• /
• v.12 no.5
• /
• pp.815-836
• /
• 1999

The role of animal agriculture for the quality of human life has always been emphasized during 20th century and it is expected to be even more important in terms of food supplies and in providing additional functions in the future. The world human population has almost tripled during a period of half century. The world population of animals has increased 2~3 times (6 times for chicken) during the last 60 years, and the total amount of livestock products has increased 5~6 times (more than 10 times in pork) with higher annual growth rate (9%) in developing countries. Increased personal income certainly encouraged demand for animal products over grains and lower animal production costs resulted from scientific and technological advances. Similarly the production of total grains has more than doubled owing to the advances in agricultural science during the later part of the 20th century. The average life span of world people in 1950s was only 46 years, which will be increased to almost 66 years in the year 2000. Present date clearly indicate that the life span of people is proportional to their income (GNP) and/or animal protein intake. Animals can provide other resources than foods. The increase of human population indicates that the number of animals as well as per capita consumption of animal products will be increased in the 21st century. The other resources we get from animals are drafts, packing, riding, hunting and herding. Guiding the blind, protection and companionship are also examples of what we can expect from animals. In the very near future, animals will become major donors of organs, skin and producers of drugs or special functional foods. It may be concluded that animals are very closely associated and related to the quality of human life, and they are expected to remain the same way in the 21st century.

• Earthquakes and Structures
• /
• v.15 no.6
• /
• pp.583-593
• /
• 2018

Seismic performance is particularly important for life-line structures, especially for long-span transmission tower line system subjected to multi-component ground motions. However, the influence of multi-component seismic loads and the coupling effect between supporting towers and transmission lines are not taken into consideration in the current seismic design specifications. In this research, shake table tests are conducted to investigate the performance of long-span transmission tower-line system under multi-component seismic excitations. For reproducing the genuine structural responses, the reduced-scale experimental model of the prototype is designed and constructed based on the Buckingham's theorem. And three commonly used seismic records are selected as the input ground motions according to the site soil condition of supporting towers. In order to compare the experimental results, the dynamic responses of transmission tower-line system subjected to single-component and two-component ground motions are also studied using shake table tests. Furthermore, an empirical model is proposed to evaluate the acceleration and member stress responses of transmission tower-line system subjected to multi-component ground motions. The results demonstrate that the ground motions with multi-components can amplify the dynamic response of transmission tower-line system, and transmission lines have a significant influence on the structural response and should not be neglected in seismic analysis. The experimental results can provide a reference for the seismic design and analysis of long-span transmission tower-line system subjected to multi-component ground motions.

• Korean Journal of Construction Engineering and Management
• /
• v.6 no.2 s.24
• /
• pp.111-119
• /
• 2005

Although the life-spans of most apartment buildings are over fifty years, they are often demolished and retrofitted only after twenty years, in spite of its remaining life expectancy, resulting in economical waste. The purpose of this paper is to estimate optimum remodeling period of apartment buildings using total cost. In this study it is seen that total sum of running cost of life-span on the buildings is about 4.69 times of initial cost till the fifty years of the life expectancy. The optimum remodeling period of the apartment building is thirty years applying the discount rate of $4.17\%$ and the discount rate should be $6.122\%$ to obtain the forty years of the optimum remodeling period. From the sensitivity analysis based on the change of the discount rates, it is seen that if discount rate decreases the optimum remodeling period can be extended, or vice versa. As a result, a time of the demolished and remodeling can be expected and the basic data can also be established for lengthening life-span of the apartment buildings.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2012.05a
• /
• pp.795-796
• /
• 2012

• 한국도로학회:학술대회논문집
• /
• 2005.03a
• /
• pp.27-34
• /
• 2005

• Journal of Chest Surgery
• /
• v.19 no.3
• /
• pp.522-527
• /
• 1986

There have been several reports of abdominal aortic aneurysm according to increase in life span and greater awareness of the diagnosis in Korea. We had a surgical experience of abdominal aortic aneurysm due to arteriosclerosis in 76 years old male. With abdominal sonogram, he was diagnosed. Aortoiliac bypass was done with double velour Dacron Y graft. Postoperative course was uneventful.