• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.7 no.4
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• pp.221-225
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• 2002

The first laboratory culture of host-parasite system of Prorocentrum minimum- Amoebophrya sp. was established by single cell isolation method. Here, we report the life cycle stages of the parasitic dinoflagellate. Amoebophrya sp. of the red tide dinoflagellate P. minimum as observed by light and epifluorescence microscopy. Infections developed inside the nucleus of P. minimum. The trophont developed to occupy almost all the intracellular space of the host at its late stage. The fully developed trophont finally ruptured through the host cell. “Vermiform stage”, the free-swimming extracellular lift cycle stage is followed by another stage for the sudden release of many individual dinospores. Our laboratory strain of the host-parasite system for P. minimum, a causative species fur the huge red tides in spring and summer in Korean coastal waters, could be a useful living material for the in situ biological control of harmful algal blooms.

• Horticultural Science & Technology
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• v.31 no.5
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• pp.573-579
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• 2013

This study was conducted to investigate optimal harvesting stage and the effects on cut roses of Korean cultivar harvested at different stages. Cut roses are harvested at three different flowering stages. The optimal harvesting stage of cut roses was different depending on varieties. The vase life of standard type 'Pink Song' and spray type 'Peace One' was extended when they were harvested in one and three stages, respectively. The vase life was generally increased when the cut roses were pretreated with a solution containing 2% sucrose + $200mg{\cdot}L^{-1}$ aluminum sulfate + $200mg{\cdot}L^{-1}$ $Mg(NO_3)_2$ + $50mg{\cdot}L^{-1}$ $CaCl_2$ as compared to the control regardless of the harvesting stage. And this pretreatment solution improved the flower quality of cut roses bred in Korea. But the effects of pretreatment were varied depending on the harvesting stage.

• Parasites, Hosts and Diseases
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• v.61 no.1
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• pp.33-41
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• 2023

The discovery of new antimalarial drugs can be developed using asynchronized Plasmodium berghei malaria parasites in vivo in mice. Studies on a particular stage are also required to assess the effectiveness and mode of action of drugs. In this report, we used endoperoxide 6-(1,2,6,7-tetraoxaspiro [7.11] nonadec-4-yl) hexan-1-ol (N-251) as a model antimalarial compound on P. chabaudi parasites. We examined the antimalarial effect of N-251 against ring-stage- and trophozoite-stage-rich P. chabaudi parasites and asynchronized P. berghei parasites using the 4-day suppressive test. The ED₅₀ values were 27, 22, and 22 mg/kg, respectively, and the antimalarial activity of N-251 was verified in both rodent malaria parasites. To assess the stage-specific effect of N-251 in vivo, we evaluated the change of parasitemia and distribution of parasite stages using ring-stage- and trophozoite-stage-rich P. chabaudi parasites with one-day drug administration for one life cycle. We discovered that the parasitemias decreased after 13 and 9 hours post-treatment in the ring-stage- and trophozoite-stage-rich groups, respectively. Additionally, in the ring-stage-rich N-251 treated group, the ring-stage parasites hindered trophozoite parasite development. For the trophozoite-stage-rich N-251 treated group, the distribution of the trophozoite stage was maintained without a change in parasitemia until 9 hours. Because of these findings, it can be concluded that N-251 suppressed the trophozoite stage but not the ring stage. We report for the first time that N-251 specifically suppresses the trophozoite stage using P. chabaudi in mice. The results show that P. chabaudi is a reliable model for the characterization of stage-specific antimalarial effects.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.6
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• pp.1583-1591
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• 1990

Life prediction and residual life prediction of structures of machines are one of the most strongly world wide needed problems as requirement in the stage of slowly developing economy which comes after rapidly and highly developing stage. For the purpose of statistical life prediction, fatigue test was conducted under the 4 stress levels, and for each stress level, about 20 specimens are used. The statistical properties of crack growth parameter m and C in the fatigue crack growth law of da/dN=C(.DELTA.K)sup m/, and the relationship between m and C, and the statistical distribution pattern of fatigue crack growth rate can be obtained by experimental results.

• Journal of Home Health Care Nursing
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• v.12 no.1
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• pp.136-154
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• 2005

Purpose : This study purposed to conduct a comprehensive survey of home care nursing clients' quality of life based on the PRECEDE model. Method : This study selected 74 home care nursing clients registered at a university hospital in Incheon and performed face-to-face interviews by structured questionnaire. The research period was two months from the $2^{nd}$ of February to the $30^{th}$ of March in 2004. Result : According to the result of assessment at each stage of the PRECEDE model, home care nursing clients' quality of life was 13.88 out of 25 points, health level 15.22 out of 21, abilities to perform activities of daily living 29.26 out of 100, cognitive abilities 16.00 out of 30, social support 13.68 out of 20, and satisfaction with home care nursing service 33.26 out of 40. According to the result of stepwise regression in order to identify factors influencing home care nursing clients' quality of life, social support and abilities of daily living were found to be significant variables among the characteristics of each assessment stage. Conclusion : It is necessary to develop nursing intervention strategies for strengthening social support and enhancing abilities to perform activities of daily living in order to improve home nursing clients' quality of life.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.4
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• pp.168-176
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• 2014

The enterprise life cycle derived from the product life cycle consists of introduction, growth, maturity and decline. The enterprise tries to reach the growth stage early and stay at the maturity stage stably through expanding its businesses and investing for the new technology. The public enterprise is not different but its life cycle is more prone to be affected by the national development and policy. A typical example can be found in the case of the quasi market SOC public enterprise which spends massive amount of fund to provide social infrastructure. After the fulfillment of its mandated mission it is exposed to the pressure of a merger or a closure usually because large portion of the debt is directly linked to the national financial stability and credit ratings. This research is focused on the variables that influence the life cycle of the quasi market SOC public Enterprise for its future competitiveness is in connection with its normalization, advancement and rationalization. In this respect, categorical variables system centering on public characteristics and profitability drew eight categorical variables such as policy outcomes, public benefit, finance and business values etc.

• The Korean Journal of Ecology
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• v.8 no.4
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• pp.179-196
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• 1985

By using temperatures as a key variable, a simulation model was constructed to predict the size and developmental speed for the German cockroach population. The following three research steps were conducted to implement the individual simulation technique to represent the basic life system of the cockroach. First, informations on developmental periods and survival rates in each life stage were obtained through rearing experiments at five different temperatures. Secondly, biological parameters needed for modeling were obtained based on these rearing results. The logistic equation was applied to calculating the developmental speed, while the averages of survival rates were utilized as parameters determining population size. And thirdly, a basic life model was constratued in a stimulative framework in FORTRAN for predicting the populating development on the individual basis. For this purpose the biological characteristics, such as life stage, age in days, developmental speed, fecundity, etc., were assigned as an inherent attribute of the transactiion so that they could accompany each individual automatically all through the simulation. This gave the model flexibility and applicability in representing the isnect life system. The save memory space in computer programing, two files were utilized in translocating the individual informations each other as time proceeded. The developed model could be effectively used as a strategic tool in interpreting and managing the cockroach population. It was also suggested in this study that the individual simulation could efficiently serve as a basis to formulate a fundamental framework on which the advanced and complex life process could be built.

• Journal of Hospice and Palliative Care
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• v.26 no.2
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• pp.95-100
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• 2023

With the implementation of Act on Hospice and Palliative Care and Decisions on Life-Sustaining Treatment for Patients at the End of Life, interests of the general public on self-determination right and dignified death of patients have increased markedly in Korea. However, "self-determination" on medical care is misunderstood as decision not to sustain life, and "dignified death" as terminating life before suffering from disease in terminal stage. This belief leads that physician-assisted suicide should be accommodated is being proliferated widely in the society even without accepting euthanasia. Artificially terminating the life of a human is an unethical act even though there is any rational or motivation by the person requesting euthanasia, and there is agreement thereof has been reached while there are overseas countries that allow euthanasia. Given the fact that the essence of medical care is to enable the human to live their lives in greater comfort by enhancing their health throughout their lives, physician-assisted suicide should be deemed as one of the means of euthanasia, not as a means of dignified death. Accordingly, institutional organization and improvement of the quality of hospice palliative care to assist the patients suffering from terminal stage or intractable diseases in putting their lives in order and to more comfortably accept the end of life physically, mentally, socially, psychologically and spiritually need to be implemented first to ensure their dignified death.

• Journal of Life Science
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• v.8 no.3
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• pp.305-311
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• 1998

These studies were undertaken to investigate changes of neutral lipid content and fatty acid composition were determined. Also accumulation process of monoglyceride, diglyceride and triglyceride content, and fatty acid composition were investigated during the development. The results were summarized as follows ; Changes of lipid during development sesame seeds, glycolipid contents which showed the highest in the early ripening stage and after that rapidly decreased, and phospholipid contents showed a similar pattern as glycolipid occurred. In contrast, the content of neutral lipid was rapidly increased by 29.21% 10 days after flowering(DAF), and showed the highest value by 91.84% at 40th day after flower. The neutral lipid, triglyceride content was rapidly increased as the seeds developed, and consisted of over 60% of the neutral lipid since 30 DAF. In the changes of neutral lipid, phospholipid and glycolipid, stearic acid and palmitic acid decreased during the seed ripening. However, oleic acid and linoleic acid increased during the same periods. Linolenic acid, which showed relatively higher value in the early ripening stage, but rapidly decreased as much as 1% at the later ripening stage.

• Transactions of the Korean Society of Mechanical Engineers
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• v.7 no.1
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• pp.28-35
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• 1983

Quantitative analysis have been carried out on the micro-cracks on the surface and into the depth of unnotched smooth mild steel specimen under cyclic stains by rotating bending fatigue tests. Some of the results are; (1) Cracks initiate at the early stage of fatigue life N$_{I}$/ N$_{f}$=10 to 20%, and propagate during the rest of fatigue life. (2) Coalescence of highly crowded small fatigue cracks of random distribution seems to induce the final fracture at higher stress level. (3) The curves of crack initiation and the equal crack length on the graph of stress versus number of cycles are parallel to the S-N curve. (3) The curves of crack initiation and the equal crack length on the graph of stress versus number of cycles are parallel to the S-N curve. (4) The distributions of micro-surface crack length and depth show the composite Weibull distributions which are approximated to two straight lines separated by the value of transient region between stage I and stage II crack.k.k.