• Journal of the Korea Society of Computer and Information
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• v.12 no.2 s.46
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• pp.63-70
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• 2007

The Data Encryption Standard (DES) is a block cipher that encrypts a 64 bit block of plaintext into a 64 bit block of ciphertext. The DES has been a worldwide standard for 20 years since it was adopted in 1976. strong. But, due to the rapid development of hardware techniques and cryptanalysis, the DES with 64-bit key is considered to be not secure at the present time. Therefore it became necessary to increase the security of DES. The NG-DES(New Generation DES)[1] is an encryption system which upgrades the encryption security of DES by the key extension and the usage of non-linear f function. It extends not only the size of plaintext and ciphertext to 128 bit but also the Fiestel structure used in each round. This structure has a weak point that the change of each bit of plaintext does not affect all bits of ciphertext simultaneously. In this paper, we propose a modified Fiestel structure of DES and thus increased confusion and diffusion by effectively cross-connecting between outputs in a round and inputs in next round.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.580-589
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• 2019

Indonesia has a very short supply of electricity. As a solution to this problem, plans for construction of thermal power plants are increasing. Thermal power plant require the cooling water system to cool the overheated engine and equipment that accompany power generation, and the circulation water pump chamber among the cooling water system are generally designed according to the ANSI (1998) standard. In this study, the design criterion $20^{\circ}$ for the spreading angle of the ANSI (1998) of the layout of the circulating water pump chamber can not be satisfied on the K-coal thermal power plant site condition in Indonesia. Therefore, 3-D numerical model experiment was carried out to obtain a hydraulically stable flow and stable structure. The Flow-3D model was used as numerical model. In order to examine the applicability of the Flow-3D model, the flow study results around the rectangular structure of Rodi (1997) and the numerical analysis results were compared around the rectangular structures. The longitudinal velocity distribution derived from numerical analysis show good agreement. In order to satisfy the design velocity in the circulating water pump chamber, a rectangular baffle favoring velocity reduction was applied. When the approach velocity into the circulating water pump chamber was occurred 1.5 m/s ~ 2.5 m/s, the angle of the separation flow on the baffle was occurred about $15^{\circ}{\sim}20^{\circ}$. By placing the baffle below the separation flow angle downstream, the design velocity of less than 0.5 m/s was satisfied at inlet bay.

• The Journal of the Convergence on Culture Technology
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• v.5 no.4
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• pp.307-313
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• 2019

In 2019, Single person households became the most common in Korea. For those households, so called 'Mukbang' and 'Cookbang', the 'Food' related TV and internet programs are so popular and even became worldwide trends. This study explored how the characteristics of the food related programs on TV and internet influence the constant single person households viewers of the dietary self efficacy. The perceived usefulness and the ease of use shows meaningful influences to the dietary self efficacy in all of the generation groups. In young adult generation from 20s to 30s old, the joyfulness is also effective variables to affect the dietary self efficacy.

• Journal of the Korean Society for Library and Information Science
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• v.49 no.3
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• pp.253-272
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• 2015

This study analyzed library awareness and anxiety among people in their 20s living in East Asia. The objective is to develop the international library cooperation agenda for life-long education proliferation. User groups in Korea, China, and Japan were investigated to understand the differences in library awareness based on the situational contexts such as preferred resources, use frequency, educational level, and gender. Results of the data analysis showed the correlation between library anxiety and use patterns such as preferred information sources and frequency of use. Specifically, the user group in China has the highest level of library anxiety with every factor. Also, the Korean user group was measured to have the lowest level of library anxiety in terms of digital information factor. Based on these results, the study presents several recommendations for resolving library anxiety such as embracing new information need with regard to environmental change and suggesting a new space policy for libraries.

• Korean Chemical Engineering Research
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• v.56 no.4
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• pp.496-523
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• 2018

The objective of this study is to evaluate the economic feasibility of two fast pyrolysis and biooil upgrading (FPBU) plants including feed drying, fast pyrolysis by fluidized-bed, biooil recovery, hydro-processing for biooil upgrading, electricity generation, and wastewater treatment. The two FPBU plants are Case 1 of an FPBU plant with steam methane reforming (SMR) for $H_2$ generation (FPBU-HG, 20% yield), and Case 2 of an FPBU with external $H_2$ supply (FPBUEH, 25% yield). The process flow diagrams (PFDs) for the two plants were constructed, and the mass and energy balances were calculated, using a commercial process simulator (ASPEN Plus). A four-level economic potential approach (4-level EP) was used for techno-economic analysis (TEA) under the assumption of sawdust 100 t//d containing 40% water, 30% equity, capital expenditure equal to the equity, $H_2$ price of $1050/ton, and hydrocarbon yield from dried sawdust equal to 20 and 25 % for Case 1 and 2, respectively. TCI (total capital investment), TPC (total production cost), ASR (annual sales revenue), and MFSP (minimum fuel selling price) of Case 1 were $22.2 million, $3.98 million/yr, $4.64 million/yr, and $1.56/l, respectively. Those of Case 2 were $16.1 million, $5.20 million/yr, $5.55 million/yr, and $1.18/l, respectively. Both ROI (return on investment) and PBP (payback period) of Case 1(FPBU-HG) and Case 2(FPBU-EH) were the almost same. If the plant capacity increases into 1,500 t/d for Case 1 and Case 2, ROI would be improved into 15%/yr.

• Korean Journal of Hospice Care
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• v.5 no.1
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• pp.50-62
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• 2005

The elderly people was over 8.3% in 2003. This seament is projected to grow to 14.4% by 2019(Aged society) and over 20% by 2026(Super aged society). As the elderly population is increasing and young population is declined social issues around elderly care are emerged in Korea. As a result of that, they are in the condition of poor system of the welfare of the old and it is the worst one in Korea. And because of the worst financial independence and difficulty in Korea, welfare facilities and medical instruments are so insufficient and deteriorated, so the quality of service is getting low. Furthermore the mortality of cancer is rapidely increased in recent years. So it is expected that the number of families who are caring for terminal cancer patient will be increased. We can not solve those problems only with government's policy such as to secure ample budget and to enlarge the aged welfare institutions. Definitely, to acheve the suggetions persistence concern about old people is most important, and family, community and national government should be linked to accomplish to goal. Accordingly, for this study attempts to provide conceptual framework of the respite care, spiritual care and home hospice, nursing home for the elderly. And this study is to discuss the necessity and effect about the construction of housing welfare infrastructure and to make a cooperation and linkage system among the aged welfare institutions, government and the aged welfare programs. As is well known, the issue of the increasing aged people is neither a matter of individuals nor of the family, but rather a complex matter of whol society. Therefore it can be resolved by the active participation of government. Conclusively this study tries to provide an direction of the improvement with regard to the welfare policy for the elderly. The study is as follwos: Chapters 1: The theological base, conception, essentiality, respite care, spiritual care and home hospice, nursing home for the elderly. Chapters 2: Definitions of respite care, spiritual care, hospice, patient of termina cancer and quality of life. And relations between respite care and nursing home. Chapters 3: The necessity of long-term care insurance and the perspectives of spiritual care. Chapters 4: Conclusions and summarizing(The directions of improvement of welfare policy for the elderly). To sum up, the problems of the aged people has not effects only to the aged people. This means that the problems of aged is the problems of the young generation today. Because young generation will be the old generation in the near future.

• Korean Journal of Food Science and Technology
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• v.37 no.5
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• pp.850-855
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• 2005

Model was developed to predict the growth of Listeria monocytogenes in raw pork. Experiment condition for model development was full 5-by-7 factorial arrangements of temperature (0, 5, 10, 15, and $20^{\circ}C$) and time (0, 1, 2, 3, 18, 48, and 120 hr). Gompertz values A, C, B, and M, and growth kinetics, exponential growth rate (EGR), generation time (GT), lag phase duration (LPD), and maximum population density (MPD) were calculated based on growth increased data. GT and LPD values gradually decreased, whereas EGR value gradually increased with increasing temperature. Response surface analysis (RSA) was carried out using Gompertz B and M values, to formulate equation with temperature being main control factor. This equation was applied to Gompertz equation. Experimental and predictive values for GT, LPD, and EGR, compared using the model, showed no significant differences (p<0.01). Proposed model could be used to predict growth of microorganisms for exposure assessment of MRA, thereby allowing more informed decision-making on potential regulatory actions of microorganisms in raw pork.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.04a
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• pp.129-132
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• 2000

The PDP(Plasma Display Panel) barrier rib material on the glass substrate was patterned for fabrication of the PDP cell using Nd:YAG laser(1064 nm) which can generate the second(532 nm) and forth(266 nm) harmonic wave by HGM(harmonic generation modules). At a scan speed of 20 ${\mu}m/s$ with the second harmonic wave(532 nm) of Nd:YAG laser, the etching threshold laser fluence of the PDP material was 6.5 $mJ/cm^2$ and a sample(thickness = 180 ${\mu}m$) on the glass substrate was removed clearly at a laser fluence of 19.5 $mJ/cm^2$. In order to increase the throughput of the fabrication we divided a single-beam into multi-beams by using a metal mask between the sample and the focusing lens. As a result, 10 lines of PDP cell were formed by one laser beam scanning at a scan speed of 200 ${\mu}m/s$ and a laser fluence of 2.86 $J/cm^2$.

• Journal of Korean Academy of Nursing
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• v.38 no.6
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• pp.813-821
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• 2008

Purpose: This study was conducted to develop an instrument measuring awareness of osteoporosis. Methods: The process included construction of a conceptual framework, generation of 86 preliminary items, verification of content validity, selection of secondary items, verification of construct validity and extraction of final items. The 86 items were reviewed for content validity by two groups of experts and were tested to evaluate inter item correlation coefficient by two groups of adult women. From June to August 2007, data were collected from 383 adult women who lived in Seoul and provinces in Korea. Data were analyzed by performing item analysis, Varimax factor analysis and Cronbach's alpha. Results: There were 31 items in the final instrument categorized into 5 factors. The factors were labeled as "preventive behaviors (10 items)", "risk factors (5 items)", "characteristics of osteoporosis (6 items)", "improving bone health (5 items)", and "bone physiology (5 items)". Cumulative percent of variance was 60.92% and eigen values ranged from 1.20 to 12.44. Cronbach's alpha was .948 and ranged from .804 to .917. Conclusion: Validity and reliability of the scale are confirmed in this study showing its utility for measuring awareness of osteoporosis for women. Utilization of the scale will also contribute to designing an appropriate prevention program for osteoporosis.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.10 no.2
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• pp.77-84
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• 2015

According to a recent survey, the sales amount of luxuries and imitations is getting larger. Especially young consumers in 2,30's have a strong desire to own luxuries, so I tried to build a theoretical base on the 20's consuming trend. Meanwhile, targeting university students who represent consumers in 20's, I investigated the recognition of luxuries, shopping experience, main shopping items, monthly spending money, and future purchase intention. I also investigated shopping experience of imitation, main shopping items, purchase reasons, and future purchase intention. I tried to suggest lots of academic and practical implications in marketing strategy building of luxury brand, aiming young consumers in 20's. On the social-psychological view point, young generation have relatively weak sense of control or self-efficacy. So, they are easily submerged in conspicuous consumption by the atmosphere around. As a result of empirical research, I found that Korean students recognized luxuries as excellent in quality, or the world famous brand. In particular, statistically significant gender difference was shown in the luxuries characteristics as the high-quality brand for male students and the world famous brand for female students. Most respondents have experience buying luxuries. And more monthly spending money, more experience they have. Respondents' purchased items were in order of fashion goods, clothing, watches/jewelry, cosmetics/perfume. And the statistically significant differences between gender and monthly spending money were shown. Not many respondents purchased luxuries imitations, and main purchased items were fashion goods. Most of purchase motives are price over quality and economy reason. The phenomena that the respondents of relatively high levels of monthly spending money had lots of luxuries imitations shopping experiences is interesting. Female students showed higher purchase intention for luxuries and imitations than male students. There was no statistically significant difference in grade level, but was found something interesting in monthly spending money. As monthly spending money increased, the purchase intention of luxuries increased, but the purchase intention of luxuries imitations decreased. However, non-linear trend was shown in the specific allowance level. This is replicate of the luxuries imitations purchase experience. Following studies will be needed for the exact interpretation for this. This study is an exploratory and descriptive, but can provide lots of fruitful academic and practical implications in formulating luxuries marketing strategies.