• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.53-53
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• 2008

Piezoelectric transformers have been widely used such as DC-DC convertor, invertor, Ballast, etc. Because, the y have some merits compared with electro-magnetic transformers such as step-up ratio, high efficiency, small size and lg hit weight, etc. Piezoelectric transformer require high electromechanical coupling factor kp in order to induce a large out put power in proportional to applied electric field. And also, high mechanical quality factor Qm is required to prevent mechanical loss and heat generation. In general, PZT system ceramics should be sintered at high temperatures between 1200 and $1300^{\circ}C$ in order to obtain complete densification. Accordingly, environmental pollution due to its PbO evaporation. Hence, to reduce its sintering temperature, various kinds of material processing methods such as hot pressing, high energy mill, liquid phase sintering, and using ultra fine powder have been performed. Among these methods, liquid phase sintering is basically an effective method for aiding densification at low temperature. In this study, In order to comparis on low temperature sintering and solid state sintering piezoelectric transformers, rosen type transformers were fabricated u sing two PZT ceramics compositions and their electrical properties were investigated.

• The Journal of Internal Korean Medicine
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• v.32 no.4
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• pp.565-583
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• 2011

Objectives : This study investigated the biochemical mechanisms of anti-proliferative and pro-apoptotic effects of the water extract of Dan-Seon-Tang (DST) in human leukemia U937 cells. Methods : U937 cells were exposed to DST and growth inhibition was measured by MTT assay. Results : Exposure of U937 cells to DST resulted in the growth inhibition in a concentration-dependent manner. This inhibitory effect was associated with morphological changes and apoptotic cell death such as formation of apoptotic bodies, increased populations of apoptotic-sub G1 phase and induction of DNA fragmentation. The induction of apoptotic cell death in U937 cells by DST was associated with up-regulation of death receptor 4 (DR4) and down-regulation of Bid, surviving and cellular inhibition of apoptosis protein-2 (cIAP-2) expression. DST treatment also induced the proteolytic activation of caspase-3, caspase-8 and caspase-9, and a concomitant degradation of caspase-3 substrate proteins such as poly (ADP-ribose) polymerase (PARP), phospholipase (PLC)-${\gamma}1$, ${\beta}$-catenin and DNA fragmentation factor 45/inhibotor of caspase activated DNAse (DFF45/ICAD). Furthermore, apoptotic cell death by DST was significantly inhibited by caspase-3 specific inhibitor z-DEVD-fmk, demonstrating the important role of caspase-3. Conclusions : These findings suggest that herb prescription DST may be a potential chemotherapeutic agent for the control of human leukemia U937 cells; further study is needed to identify the active compounds.

• Journal of the Korea Society of Computer and Information
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• v.25 no.10
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• pp.15-22
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• 2020

In this study, we propose an improvement method that can create U-Net model which detect fine concrete cracks by applying a weighted loss function. Because cracks in concrete are a factor that threatens safety, it is important to periodically check the condition and take prompt initial measures. However, currently, the visual inspection is mainly used in which the inspector directly inspects and evaluates with naked eyes. This has limitations not only in terms of accuracy, but also in terms of cost, time and safety. Accordingly, technologies using deep learning is being researched so that minute cracks generated in concrete structures can be detected quickly and accurately. As a result of attempting crack detection using U-Net in this study, it was confirmed that it could not detect minute cracks. Accordingly, as a result of verifying the performance of the model trained by applying the suggested weighted loss function, a highly reliable value (Accuracy) of 99% or higher and a harmonic average (F1_Score) of 89% to 92% was derived. The performance of the learning improvement plan was verified through the results of accurately and clearly detecting cracks.

• Journal of the Korea Fashion and Costume Design Association
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• v.14 no.3
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• pp.51-65
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• 2012

This research was conducted to provide basic data for the formulation of marketing strategies suitable to the increasingly globalizing clothing market for the elderly in the fashion industry, by comparing the clothing behavior and preferences of elderly women aged over 70 years in Korea with those of women in the U.S. The 106 questionnaire responses that were collected in the U.S. and the 235 responses that were collected in Korea were used for the analysis, The major objectives of this study were as follow; 1. It was found that the elderly women of Korea utilize mostly human information as information source when purchasing clothing, whereas women of U.S. utilize mostly media information. Comfort was found to be most important factor both countries, but the Korean women considered the aesthetic aspect of clothing more important than did American women. 2. The clothing preference of Korean elderly women aged over 70 years was concentrated in young and feminine images regardless of items, so it could be seen that they had strong desire for looking young. But American elderly women showed different preference depending on items, so it could be seen that they pursue diverse images depending on clothing items and personality without concentrating in one image. The comparison of the preference style by item of elderly women over 70 years of age between Korea and the U,S. showed significant difference. Accordingly, the designs of the clothes of the Korean and American women should be differentiated and developed according to the clothes item and country.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7331-7333
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• 2013

Aim: To investigate associations of fasting insulin and glucose levels in serum with hepatocellular carcinoma risk. Materials and Methods: This hospital based study was carried out using data retrieved from the register maintained in the Department of Biochemistry of the Nepalese Army Institute of Health Sciences, between 1st December, 2011 and 31st June, 2013. The variables collected were age, fasting plasma glucose, fasting plasma insulin and ALT. Quantitative determination of human insulin concentrations was accomplished by chemiluminescence enzyme immunoassay. Results: Of the total 220 subjects enrolled in our present study, 20 cases were of HCC and 200 were healthy controls. The maximum number of cases of hepatocellular carcinoma in category cutpoints of fasting insulin levels fell in the range of >6.10 ${\mu}U/ml$. The highest insulin levels (>6.10 ${\mu}U/ml$) were seen to be associated with an 2.36 fold risk of HCC when compared with fasting insulin levels of (<2.75 ${\mu}U/ml$). Furthermore, the insulin levels (2.75-4.10 ${\mu}U/ml$) of category cutpoints also conferred a 1.57 fold risk for HCC when compared with lowest fasting insulin levels of (<2.75 ${\mu}U/ml$). Conclusions: The effect of an insulin level in increasing HCC risk appeared consistent, influencing incidence, risk of recurrence, overall survival, and treatment-related complications in HCC patients.

• Archives of Pharmacal Research
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• v.28 no.6
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• pp.685-690
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• 2005

We recently reported that the ginseng saponin metabolite, compound K (20-O-$\beta$-D-glucopyra-nosyl-20(S)-protopanaxadiol, IH901), inhibits the growth of U937 cells through caspase-dependent apoptosis pathway. In this study, we further characterized the effects of compound K on U937 cells and found that, in addition to apoptosis, compound K induced the arrest of the G1 phase. The compound K treated U937 cells showed increased p21 expression; an inhibitory protein of cyclincdk complex. The up-regulation of p21 was followed by the inactivation of cyclin D and the cdk4 protein, which act at the early $G_1$ phase, and cyclin E, which acts at the late $G_1$ phase. Furthermore, compound K induced the activation of JNK and the transcription factor AP-1, which is a downstream target of JNK. These findings suggest that the up-regulation of p21 and activation of JNK in the compound K treated cells contribute to the arrest of the $G_1$ phase.

• Journal of the Korea Safety Management & Science
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• v.10 no.4
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• pp.181-187
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• 2008

The market of air cargo in Korea grows very quickly and diversifies. It is an essential factor in the process of development of Northeast-Asia as a hub for Air Cargo logistics. But the process of air cargo in Korea is complex as compared with other north-east asia nations and it has many problems and causes inconvenience to owners of freight. We emphasize that 4PL(Fourth party Logistics) is the excellent solution from among many alternatives. The wave of 4PL added to strategic consulting based on new IT techniques, for example RFID, with logistics outsourcing through existing 3PL service is a great issue. It is also worthy of notice that EPCglobal network strengthen the role of 4PL. In conclusion, the 4PL system based on EPCglobal network will result in a good success, so it will raise a prestige of air cargo in Korea to a higher position. This study deals with the new logistics system, air cargo logistics system based on u-4PL system, RFID and EPCglobal network, that will bring many advantages. At the end, we verify the u-4PL air cargo logistics system by simulation tool.

• Nuclear Engineering and Technology
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• v.54 no.2
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• pp.523-531
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• 2022

In order to study the sensitivity and the uncertainty of the Moroccan research reactor TRIGA Mark II, a model of this reactor has been developed in our ERSN laboratory for use with the N-Particle MCNP Monte Carlo transport codes (version 6). In this article, the sensitivities of the effective multiplication factor of this reactor are evaluated using the ENDF/B-VII.0, ENDF/B-VII.1 and JENDL-4.0 libraries and in 44 energy groups, for the cross sections of the fuel (U-235 and U-238) and the moderator (H-1 and O-16). However, the quantification of the uncertainty of the nuclear data is performed using the nuclear code NJOY99 for the generation and processing of covariance matrices. On the one hand, the highest uncertainty deviations, calculated using the ENDFB-VII.1 and JENDL4.0 evaluations, are 2275, 386 and 330 pcm respectively for the reactions U₂₃₅(n, f), $ U_{235}(n\bar{\nu})$ and H₁(n, γ). On the other hand, these differences are very small for the neutron reactions of O-16 and U-238. Regarding the neutron spectra, in CT-mid plane, they are very close for the three evaluations (ENDF/B-VII.0, ENDF/B-VII.1 and JENDL-4.0). These spectra present two peaks (thermal and fission) around the energies 0.05 eV and 1 MeV.

• Journal of Animal Science and Technology
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• v.66 no.2
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• pp.279-294
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• 2024

Agriculture has played a significant role in the national economy, contributing to food security, driving economic growth, and safeguarding the dietary habits of the population. Korean agriculture has been compelled to focus on intensive farming due to its limited cultivation area, excessive input costs, and the limitations of agricultural mechanization. In the Republic of Korea (R.O.K), the concept of environmentally friendly animal agriculture began to be introduced in the early 2000s. This concept ultimately aims to cultivate sustainable animal agriculture (SAA) through environmentally friendly production practices, ensuring the healthy rearing of animals to supply safe animal products. Despite the government's efforts, there are still significant challenges in implementing environmentally friendly agriculture and SAA in the R.O.K. Therefore, the objective of this review is to establish the direction that the animal agriculture sector should take in the era of climate crisis, and to develop effective strategies for SAA tailored to the current situation in the R.O.K by examining the trends in SAA in the U.S. The animal agriculture sector in the U.S. has been working towards creating a SAA system where humans, animals, and the environment can coexist through government initiatives, industry research, technological support, and individual efforts. Efforts have been made to reduce emissions like carbon, and improve factors affecting the environment such as the carbon footprint, odor, and greenhouse gases associated with animal agriculture processes for animals such as cattle and pigs. The transition of the U.S. towards SAA appears to be driven by both external goals related to addressing climate change and the primary objectives of responding to the demand for safe animal products, expanding consumption, and securing competitiveness in overseas export markets. The demand for animal welfare, organic animal products, and processed goods has been increasing in the U.S. consumer market. A major factor in the transformation of the U.S. animal agriculture sector in terms of livestock specifications is attributed to environmentally friendly practices such as high-quality feed, heat stress reduction, improvements in reproductive ability and growth period reduction, and efforts in animal genetic enhancement.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.7
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• pp.1074-1085
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• 2009

This study compares the benefits for online clothing purchases between Korean and U.S. consumers. A total of 464 usable questionnaires were obtained from respondents who resided in Korea (n=253) and the United States (n=21l). Data were analyzed by descriptive statistics, factor analysis, and MANOVA. For online clothing purchases, the benefit consisted of five factors: product attribute, transaction services, security, country of origin, and brand symbolism. Results showed that the main effect of nationality and gender on the benefit factors were significant; there was an effect of nationality on product attributes, transaction services, and country of origin. Compared with Korean consumer, U.S. consumers were more likely to consider the benefits of product attributes, transaction services, and country of origin for clothing in online purchases. In addition, there was a gender difference in benefit factors of product attributes, transaction services, country of origin, and brand symbolism. Females were more likely than males to consider the benefits for clothing in online purchases. An interaction effect of nationality and gender was not significant in online purchases for clothing. The managerial implications are discussed for global fashion marketing across the countries.