• 한국연소학회:학술대회논문집
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• 한국연소학회 2002년도 제25회 KOSCI SYMPOSIUM 논문집
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• pp.231-235
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• 2002

A theoretical and experimental study on the combustion process in a constant volume micro combustor is described. Unlike in a macro scale constant volume combustor, the heat loss to the wall plays a major role in flame propagation in a micro micro combustor. In order to analyze the effect of heat loss on combustion phenomena, pressure transition from ignition was measured. A number of cylindrical micro combustors with different diameter and depth were used for experiment to study the effect of length scales and shape factor. The diameter of combustor ranged from 7.5mm to 22.5 mm and the height of cylinder was from 1mm to 4mm. Initial pressure was also varied for the experiment. The diagnostic methods were severely limited due to the size of the apparatus and uncertainties of certain quantities to be measured in a small-scale environment. An analytical method to derive physical quantities that are essential for performance prediction from the pressure measurements is described.

• 약학회지
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• 제53권4호
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• pp.179-183
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• 2009

We explored the role of reactive oxygen species (ROS) in LPS-induced bone loss. LPS was shown to increase the concentration of ROS in osteoclast precursors. The antioxidant decreased osteoclast formation by LPS. Furthermore, the antioxidant decreased NFATc1 expression by LPS, suggesting that ROS mediates NFATc1 expression in the regulation of LPS-induced osteoclast formation. Finally, the antioxidant decreased LPS-induced RANKL mRNA expression in osteoblasts. Taken together, these data indicate that LPS mediates ROS to induce bone loss.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제34권5호
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• pp.518-524
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• 2008

Chromosome 18q alteration plays a key role in colorectal tumorigenesis, and loss of heterozygosity at 18q is associated with a poor prognosis in colon cancer. DCC(Deleted in Colorectal Cancer) is a putative tumor- suppressor gene at 18q21 that encodes a transmembrane protein with structural similarity to neural cell adhesion molecule that is involved in both epithelial and neuronal cell differentiation. DCC is implicated in regulation of cell growth, survival and proliferation. Thus, tumor progression in squamous cell carcinoma, stomach cancer, colorectal cancer correlates with downregulation of DCC expression. The mechanism for DCC suppression is associated with hypermethylation of the DCC gene promoter region. Hence, the goal of this study is to identify the promoter methylation responsible for the down-regulation of DCC expression in oral squamous cell carcinoma. 12 of tissue specimens for the study are excised and gathered from 12 patients who are diagnosed as SCC in department of OMS, dental hospital, dankook university. To find expression of DCC in each tissue samples, immunohistochemical staining, RT-PCR gene analysis and methylation specific PCR are processed. The results are as follows. 1. In the DCC gene RT-PCR analysis, 5(41.6%) of 12 specimens of oral squamous cell carcinoma did not expressed DCC gene. 2. In the promoter methylation specific PCR analysis, 5(41.6%) of 12 specimens showed promoter methylation of DCC gene. 3. In the immunohistochemical staining of poor differentiated and invasive oral squamous cell carcinoma, loss of DCC expression was observed. These findings suggest that methylation of the DCC gene may play a role in loss of gene expression in invasive oral squamous cell carcinoma.

• 대한간호학회지
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• 제22권2호
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• pp.157-173
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• 1992

The purposes of study were to investigate the prenatal psychological adaptation and the perception of birth experience, and to identify the relationship between them. The subjects consisted of 162 women who visited the obstetrical outpatient clinic for prenatal examinations and who delivered the in babies at SNUH during the period from June 20 to August 10, 1990. The tools used for measurement were Lederman's Prenatal Self Evaluation Questionnaire and Marut & Mercer's scale of the Perception of Birth. The results are summarized as follows : 1. The orders and item means of psychosocial adaptation in pregnancy were the Acceptance of pregnancy(1.58). Identification of motherhood role(1.63). Relationship with husband(1.65) and Relationship with mother(1.67). The preparation for labor, concern for wellbeing of self and baby, and fear of pain, helplessness and loss of control were found to be less adaptive. 2. The level of the perception of the birth experience was mid-range(item mean : 3.22). The score of the perception of birth experience for primiparas was higher than for multiparas. However there was not a significant difference the groups. There were significant differences in the perception of the birth experience between certain general characteristics, namely, sex of the baby(p＜0.05), type of delivery(p＜0.005), and type of anesthesia(p＜0.005). 3. There were significant differences in the perception of the birth experience between the groups below the mean and above the mean of concerti for wellbeing of self and baby, Fear of pain, Helplessness and loss of control, Relationship with husband and Identification of motherhood role (p＜0.05). The perception of the birth experience was predicted by Fear of pain, Helplessness and loss of control (11%), Type of Delivery(6%), Concern for wellbeing of self and baby(3%), Preparation for labor(1%), sex of baby(1%), Relationship with mother(1%), Parity(1%) and Identification of motherhood role(1%). The Childbirth education should be revised to improve the psychosocial adaptation in pregnancy.

• 한국정보기술응용학회:학술대회논문집
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• 한국정보기술응용학회 2005년도 6th 2005 International Conference on Computers, Communications and System
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• pp.271-275
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• 2005

Queueing models are good models for fragments of communication systems and networks, so their investigation is interesting for theory and applications. Theses queues may play an important role for the validation of different decomposition algorithms designed for investigating more general queueing networks. So, in this paper we illustrate that the batch size distribution affects the loss probability, which is the main performance measure of a finite buffer queues.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 A
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• pp.250-252
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• 1997

Phase difference of external magnetic field and self field is known to do an important role in the generation of the AC loss. This paper analize the AC loss of AC superconducting wire in combined action of an AC transport current and AC magnetic field for various phase differences.

• Bulletin of the Korean Chemical Society
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• 제31권9호
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• pp.2588-2592
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• 2010

The potential energy surfaces (PESs) for the primary and secondary dissociations of the phenylarsane molecular ion (1a) were determined from the quantum chemical calculations using the G3(MP2)//B3LYP method. Several pathways for the loss of $H{\cdot}$ were determined and occurred though rearrangements as well as through direct bond cleavages. The kinetic analysis based on the PES for the primary dissociation showed that the loss of $H_2$ was more favored than the loss of $H{\cdot}$, but the $H{\cdot}$. loss competed with the $H_2$ loss at high energies. The bicyclic isomer, 7-arsa-norcaradiene radical cation, was formed through the 1,2 shift of an $\alpha$-H of 1a and played an important role as an intermediate for the further rearrangements in the loss of $H{\cdot}$ and the losses of $As{\cdot}$ and AsH. The reaction pathways for the formation of the major products in the secondary dissociations of $[M-H]^+$ and $[M-H_2]^{+\cdot}$. were examined. The theoretical prediction explained the previous experimental results for the dissociation at high energies but not the dissociation at low energies.

• The Korean Journal of Physiology and Pharmacology
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• 제26권6호
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• pp.405-413
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• 2022

Hair loss is a common status found among people of all ages. Since the role of hair is much more related to culture and individual identity, hair loss can have a great influence on well-being and quality of life. It is a disorder that is observed in only scalp patients with androgenetic alopecia (AGA) or alopecia areata caused by stress or immune response abnormalities. Food and Drug Administration (FDA)-approved therapeutic medicines such as finasteride, and minoxidil improve hair loss temporarily, but when they stop, they have a limitation in that hair loss occurs again. As an alternative strategy for improving hair growth, many studies reported that there is a relationship between the expression levels of prostaglandins (PGs) and hair growth. Four major PGs such as prostaglandin D2 (PGD2₂), prostaglandin I2 (PGI₂), prostaglandin E2 (PGE₂), and prostaglandin F2 alpha (PGF_2α) are spatiotemporally expressed in hair follicles and are implicated in hair loss. This review investigated the physiological roles and pharmacological interventions of the PGs in the pathogenesis of hair loss and provided these novel insights for clinical therapeutics for patients suffering from alopecia.

• 대한가정학회지
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• 제45권7호
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• pp.61-70
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• 2007

The recent type of dysfunctional family is caused not only by the loss of a family member, which is the traditional type of dysfunction, but also by the absence of a functional aspect. In order for a family to function healthily, it is necessary to have the right child rearing by the parents and the right parental role. Accordingly, this study is to identify the difference in stress from child rearing and the parental role in dysfunctional families, which have been increasing enormously in recent times. With this aim, 45 persons from dysfunctional families owing to divorce, 51 persons from other dysfunctional families, and 48 persons from general families were subject to a test about stress from child rearing and the parental role. As a result, for stress from child rearing, mothers in dysfunctional families perceived stress from child rearing more highly than ones in general families; and also for parental role, the level of parental role was proven lower for mothers in dysfunctional families than ones in general families.

• 한국정보시스템학회지:정보시스템연구
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• 제18권3호
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• pp.327-349
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• 2009

Traditional keyword-based searching methods suffer from low accuracy and high complexity due to the rapid growth in the amount of information. Accordingly, many researchers attempt to implement a so-called semantic search which is based on the semantics of the user's query. Semantic information can be described using a semantic modeling language, such as Topic Map. In this paper, we propose a new method to map a topic map to a traditional Relational Database (RDB) without any information loss. Although there have been a few attempts to map topic maps to RDB, they have paid scant attention to handling multi-role topics. In this paper, we propose a new storage structure to map multi-role topics to traditional RDB. The proposed structure consists of a mapping table, role tables, and content tables. Additionally, we devise a query translator to convert a user's query to one appropriate to the proposed structure.