• Transactions of Materials Processing
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• 제17권2호
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• pp.124-129
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• 2008

Net shape forging technologies give many effects into the costs and qualities for the finished products. So, the studies to reduce the additional machining amount are very important in forging industry. Specially, there are two main topics in cold forging industry, such as, tool life and precision forging. In this study, new forging technique was proposed to eliminate the machining process for fixing up the length and improve the lead accuracy of gear. The luck-up hub is manufactured through many processes, such as upsetting, piercing and direct extrusion. The gear is formed in direct extrusion process; however, lead accuracy of the gear is over allowance limit. Therefore, the additional sizing process must be added. In this study, process design for closed-die forging of a lock-up hub used for a component of automobile transmission was made using three-dimensional finite element simulations, and the strain distributions and velocity distributions are investigated through the post processor. The rigid-plastic finite-element method for back pressure forging has been used in order to reduce development time and die cost. Using the FEM simulation, we found the optimum value of back pressure. The prototypes of lock-up hub parts were forged into the net-shape. In the experiment, lead precision of tooth are measured by the CCMM(Contact Coordinate Measuring Machine). The dimensional accuracy of forged part was improved up to the 40% when back press was applied.

• ETRI Journal
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• 제39권6호
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• pp.866-873
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• 2017

We propose a multilayered-substrate-based power semiconductor discrete device package for a low switching loss and high heat dissipation. To verify the proposed package, cost-effective, low-temperature co-fired ceramic, multilayered substrates are used. A bare die is attached to an embedded cavity of the multilayered substrate. Because the height of the pad on the top plane of the die and the signal line on the substrate are the same, the length of the bond wires can be shortened. A large number of thermal vias with a high thermal conductivity are embedded in the multilayered substrate to increase the heat dissipation rate of the package. The packaged silicon carbide Schottky barrier diode satisfies the reliability testing of a high-temperature storage life and temperature humidity bias. At $175^{\circ}C$, the forward current is 7 A at a forward voltage of 1.13 V, and the reverse leakage current is below 100 lA up to a reverse voltage of 980 V. The measured maximum reverse current ($I_{RM}$), reverse recovery time ($T_{rr}$), and reverse recovery charge ($Q_{rr}$) are 2.4 A, 16.6 ns, and 19.92 nC, respectively, at a reverse voltage of 300 V and di/dt equal to $300A/{\mu}s$.

• Korean Journal of Agricultural Science
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• 제32권1호
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• pp.71-80
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• 2005

Phytic acid chelates excellently the metallic ions and the positive ions, especially has high affinity with $Fe^{2+}$ and $Ca^{2+}$. Merits of phytic acid can be taked in easily, edibile and harmless to body, so it was investigated that phytic acid can be substituted for EDTA in this study. 1. The Intensificative effect of chelating agent and disinfective osmotic shock of Vibrio vulnificus The number of initial existent fungi measured $1.7{\times}10^6$. The percentages of the survival fungi against the osmotic shock by distillated water were calculated at 1 minute, 3 minute and 5 minute after inoculation. The percentages of the survival fungi in $Mg^{2+}$ were 92.5%, 91.8% and 79.8% at each time, the average percentage was 88%. Also the sudden extinction was observed around 1 minute after inoculation and the survival fungi were not observed from 3 through 5 minute in spite of repeated experimentation. 2. Influence of Vibrio vulnificus on the survival of the mice. The first mouse started to die in 180 minute after inoculation in case that the inoculating number was $2.3{\times}10^7cfu/ml$. All died within 4.5 hour. The average of survival time was 226 minute. The first mouse started to die in 228 minute after inoculation in case that the inoculating number was $0.8{\times}10^6cfu/ml$. All died within 5 hour. The average of survival time was 300 minute and the survival time was 1.3 times high. The tendencies of death in two cases were similar, but the fatal rate were largely dependent on inoculating number.

• Korean Journal of Social Welfare Studies
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• 제41권1호
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• pp.251-279
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• 2010

In 2009 the Ministry of Health and Society reported a new milestone in longevity among people living with HIV and AIDS (PLWHA): An individual was reported to be living and healthy after 24 years with HIV/AIDS. Today, PLWHA who receive treatment are more likely to die as a result of cancer or cardiovascular diseases than HIV/AIDS. However, in Korea the public association between HIV/AIDS and death remains strong and PLWHA live with the feeling of being discarded. While great advances have been made in the treatment of HIV/AIDS, understanding of life with HIV/AIDS is just beginning. This study describes the life experiences of PLWHA after being diagnosed with HIV/AIDS. Phenomenological methods were used to analyze the transcripts of semi-structured interviews with six PLWHA. Time is a constant factor in the life experiences of PLWHA. After being diagnosed, participants were shocked, feeling as though the world was caving in and they were living with a time bomb. Compulsory disclosure left PLWHA with a feeling of disconnection from the world. Participants were fired from their jobs, resulting in poverty, isolation and a sense that they were simply waiting to die. However, health professionals informed participants that HIV/AIDS is a manageable illness. With time, PLWHA came to understand HIV/AIDS differently. In accepting their HIV infection, PLWHA created a new sense of meaning in their lives. To be honest to their loved ones and true to their own identity, PLWHA worked to "come out." The experience of coming out helped them to accept themselves as they were and understand their own strength. The most important influence on their treatment, and living with HIV/AIDS generally, was obtaining correct information about HIV/AIDS from health professionals. After accepting that they were living with HIV/AIDS, participants were able to look beyond themselves to support those around them, including family members, friends, and others who encouraged them to recognize and feel confident in their own identity.

• 한국금형공학회:학술대회논문집
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• 한국금형공학회 2008년도 하계 학술대회
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• pp.203-208
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• 2008

Recently, the modern society in development and industrial growth is investing a lot of time and much effort to improvement and environment of life quality. Thus, the casting tape which uses environmentally friendly and human body friendly water hardening process Polymer is rapidly substituted for the gypsum cast product which has been plentifully used in medical treatment. Until currently, prior researches have a tendency to focusing the analysis about chemical creation expense and reaction quality rather than the issue about optimization of the process for this polymerization. In the polymerization process which has been accomplished with actual same chemical creation expense, there has been a problem which is the possibility of getting a different result. This is because the optimization of respectively control factors is not accomplished which affect at polymerization process. Therefore, this research sees the chemical qualities of casting tape Polymer, consequently selects the polymerization process which is suitable. And, by using a experimental design, this research will evaluate the affects which the respective factors have on remaining NCO and viscosity. futhermore, this research will carry out the process optimization which can get the above results.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.19-20
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• 2006

As the Mobile and Display technology are being developed quickly, new wireless devices are released in great numbers. They reduce existing devices' life time and demand a reduction of developing period of portable devices. With these demands, existing film cutting mold used many films of portable devices, especially LCD Display, needs to be more precise, and cheaper. In this research, we have analyzed machining characteristics of cutter shapes, materials, and cutting conditions for application to other films. Cutter edge was machined by slot cutting method and CAD program to select the cutter shape and cutter angle. Also, we have determined the optimal cutting conditions using high speed machining experiments to improve the productivity.

• Journal of Hospice and Palliative Care
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• 제26권2호
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• pp.80-94
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• 2023

Purpose: This study aimed to identify attitudes toward advance directives (ADs) among female cancer patients and factors related to ADs. Methods: The study was conducted at a university hospital in Seoul from September 19, 2020, to January 20, 2021. The participants were 153 patients diagnosed with gynecological cancer or breast cancer. Data were collected using questionnaires and included general characteristics, disease- and AD-related characteristics, knowledge and attitudes about ADs, and attitudes about dignified death. Data were analyzed using the t-test, analysis of variance, and multiple regression analysis. Results: Only 2% of the participants completed ADs. The mean score for attitudes toward ADs was 3.30, indicating a positive knowledge and attitude toward dignified death. The factors related to attitudes toward ADs were attitudes toward dignified death (𝛽=0.25, P=0.001), experience discussing life-sustaining treatment (𝛽=0.17, P=0.037), preferred time to have a consultation about ADs (𝛽=0.19, P=0.046), intention to write ADs (𝛽=0.15, P=0.038), and Eastern Cooperative Oncology Group Performance Status (𝛽=-0.37, P<0.001). The explanatory power of these variables for attitudes toward ADs was 38.5%. Conclusion: Overall, patients preferred to have a consultation about ADs when they were still active, mentally healthy, and able to make decisions. Education about ADs should be provided to patients on the first day of hospitalization for chemotherapy or while awaiting treatment in an outpatient setting so patients can write ADs and discuss them with family and friends.

• The Mathematical Education
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• 제44권3호
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• pp.409-433
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• 2005

This article is to provide information on school contexts for learning and instruction of mathematics based on the results and data of TIMSS 1999. It is organized around two major topics: teacher and students achievement, instruction and students achievement In this article the following summarizes the major findings. First, about $50\%$ of Korean eight-grade students were taught mathematics by teachers in their 30s, and this was higher than the international average. Most of teachers in Korea had certification of teachers majors in mathematics. Korean teachers reported relatively low confidence to teach mathematics compared to other counties. And Korean students taught by teachers who believes they were well prepared attained low achievement scores in contrast to international result. Second, korean teachers spent about $50\%$ of their formally scheduled school time teaching their subject, but is was below the international average. They spent much more time on administrative duties and other related activities than other countries. Korean students reported that most of their class time were spent lecture style presentations by teacher. Also they reported that teachers showed them how to do mathematics. The percentages of Korean students were placed on the low level of index of emphasis on mathematics reasoning and problem-solving. The students taught by teachers who emphasized reasoning and problem-solving showed low achievement scores in contrast with result of the previous literatures. Korean teachers didn't seem to emphasize homework and assessments. Internationally, teachers frequently used teacher-made objective tests and projects or practical exercises, but Korean teachers die less in most of categories. Based on the above findings, this article presents implications about teacher education, reduction of administrative working in teachers tasks, using everyday life topics, as learning materials, specialization instruction methods for each subject matter. This article is a kind of descriptive and factual in nature, but some attempt has been made to contextualize these results focused on teachers and instruction.

• Journal of Korean Academy of Nursing
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• 제27권1호
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• pp.141-155
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• 1997

The universe has its order of yang and yin : all creation are continuously generated, grow and die, which is the results of the harmonious operation by yang and yin. Among all creation, the human is one of the samjae(three bases of the world, which are heaved earth, and man) and he is from the combined sukhi(a superior khi) of yang and yin. And human life itself is basically a condensed jonghyul (life blood) and at the same time it is only a transient joining of sadae(the four elements of earth, air, fire and water). Yang and yin, the two axes of the world, therefore. are the most crucial and fundamental concept to explain the generation and extinction of alt creation, to understand people in time and space. to find out the reality of human life as an organism, and, at last, to observe the state of human health. If so, what is the most essential idea in yang and yin\ulcorner It is taegeuk(chungkhi) or tao(of one yang and one yin). If the property of heaven and earth is kongon, taegeuk is a khi and tao a principle. And it can be said that a human body is merely a union of hyung and khi, that human life is an essence of sambo, jeongkhishin, that human health is a harmoninzed coordination of yang and yin because it is from the combined sukhi of yang and yin. Hyung. a vessel for sambo, jeongkhishin, is at the bottom and shin is on the top : the personality and the disposition of individuals differ according to their working. Thus. on the basis of the above discussion. the following can be offered as some suggestions for Korean Nursing Theory. Though human beings are part of Nature, they are the most eminent microcosm among all creation. So, as a subjet for nursing, a person should be understood with khijok kyoryu rather than with logical thinking, then mutual trust between the patient and the nurse can be established. The health of a person depends on the harmony of yang and yin. To be healthy, a person should consider harmonization with Nature(including his surroundings) as well as a balanced human relationships in society. Moreover, it is crucial for each person to obtain hoshim as a method of mind control rather than to only treat the symptoms of disease.

• Journal of Korean Academy of Fundamentals of Nursing
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• 제7권2호
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• pp.271-286
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• 2000

This study is designed to investigate what elders think about the meaning of aging. We have used Q-methods to identify meaning of aging from elders, and developed self-referenced surveys to analyze characteristics In this study, we used a non-structured method to select Q sampling. From 183 Q populations, we selected 36 Q sampling. A total of 32 persons sixty-years or older were randomly selected for P samples, When the Q-sorting was complete, we interviewed the participants at both end of the extremes(agree or disagree), and documented their responses. We used PC QUANL to process the data and used principal component analysis for Q factor analysis. There were five subjective types for the meaning of aging by elders. Of the 32 P-samples of elders, 11 were identified as Type 1, 7 as Type 2, 2 as Type 3, 8 as Type 4, and 4 as Type 5. Type 1 : 'Matured elders' Elders wished the well being of their children, thought older persons should maintain good health, worried about becoming senile, and dependent God believing in life after death. Type 2 : 'Assertive-Rights' Elders categorized as Assertive-Rights insisted on their rights to life as a person. Type 2 elders characterized themselves as people who should keep themselves healthy, become weak and lack sexual desires, act selfish like a child, need to be protected, and be financially independent. Type 3 : 'Passive-Dependents' Elders characterize themselves as those who pray for their children's well being, worry about the children even after their death. and becoming senile. Type 4 : 'Hopeless' The 'Hopeless' type of elders characterized aging as a time to pray for their children, insignificant beings, thoughts were selfish and child-like, poor, worried about going senile, regret their life overall, and preferred to die than to live as an old person. Type 5 : 'Attached-Present' The 'Attached-Present' type of elders thought elderly characterized themselves as acting selfish and child-like, wiser, anxious, regret their life, stand aloof of greed and worldly things, being a model for the society, and deserving to be treated with filial respect. Thus far, Korean elders seemed to have a positive and negative meaning of aging due to the current changes in the society, value system, and family structures. The above five subjective meanings of aging confirm that we need to approach and nurse the elderly differently. Years of aging are a part of and a natural process of life with various physical, psychological, and sociological changes. Nurses need to assist elderly to find the positive meaning of their life by providing appropriate physical, psychological, and social support at an earlier stage in nursing. Based on this study, we could derive the following two implication from the perspectives of science of nursing to care for elders. 1) Based on the studies investigating the type of meaning of aging, we could develop tools to assist in nursing intervention programs for elderly. 2) Based on research on the meaning of aging for different developmental stages of life, we could develop a model for roles for different family members in nursing and caring for the elders.