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Block Replacement Scheme based on Reuse Interval for Hybrid SSD System (Hybrid SSD 시스템을 위한 재사용 간격 기반 블록 교체 기법)

  • Yoo, Sanghyun;Kim, Kyung Tae;Youn, Hee Yong
    • Journal of Internet Computing and Services
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    • v.16 no.5
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    • pp.19-27
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    • 2015
  • Due to the advantages of fast read/write operation and low power consumption, SSD(Solid State Drive) is now widely adopted as storage device of smart phone, laptop computer, server, etc. However, the shortcomings of SSD such as limited number of write operations and asymmetric read/write operation lead to the problem of shortened life span of SSD. Therefore, the block replacement policy of SSD used as cache for HDD is very important. The existing solutions for improving the lifespan of SSD including the LARC scheme typically employ the LRU algorithm to manage the SSD blocks, which may increase the miss rate in SSD due to the replacement of frequently used block instead of rarely used block. In this paper we propose a novel block replacement scheme which considers the block reuse interval to effectively handle various data read/write patterns. The proposed scheme replaces the block in SSD based on the recency decided by reuse interval and age along with hit ratio. Computer simulation using workload trace files reveals that the proposed scheme consistently improves the performance and lifespan of SSD by increasing the hit ratio and decreasing the number of write operations compared to the existing schemes including LARC.

Fermentation Characteristics of Makgeolli Containing Aronia (Aronia melanocarpa, Black chokeberry) (아로니아를 첨가한 막걸리의 발효특성)

  • Park, Mi-Jung;Kim, Hyeong-Kook;Choi, Kyong-Kun;Koo, Bon-Yeol;Lee, Si-Kyung
    • Korean Journal of Food Science and Technology
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    • v.48 no.1
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    • pp.27-35
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    • 2016
  • This study was conducted to investigate the quality characteristics of makgeolli containing aronia, (Aronia melanocarpa (0-1.9%)). After an initial decrease in the range of pH from 4.93-5.04 to 3.43-3.61 over a period of 6 days, it gradually increased until 14 days. As the fermentation proceeded, sugar contents and reducing sugar contents initially increased in majority of the samples, and subsequently decreased after 2 days. Total acidity contents increased until 6 days and then became higher as the content of aronia increased. Total acidity levels were within the range of 0.50-0.62%. After 14 days of fermentation, the alcohol contents ranged between 11.97 and 14.13%. Over the same time span, the amino acid content increased from a range of 1.57-2.22 to 5.86-6.92%. The microbial cell count and yeast colony count increased over the initial 4 days and then gradually decreased. Total polyphenol content and total flavonoid of aronia makgeolli were significantly higher than those of the control group. Based on the sensory evaluation, makgeolli with 1.3% aronia demonstrated the highest overall acceptance.

Optimum Mix Proportions of High Fluidity Antiwashout Underwater Concrete Using Ground Granulated Blast Furnace Slag (고로슬래그 미분말을 사용한 고유동 수중불분리성 콘크리트의 최적배합비 도출)

  • Kim, Sung-Wook;Park, Jung-Jun;Bae, Su-Ho;Park, Jae-Im
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.8
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    • pp.3704-3712
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    • 2012
  • Recently, antiwashout underwater concrete has been increasingly used for marine foundations of long span bridges. However, to shorten the construction period of antiwashout underwater concrete used in marine foundations, high fluidity antiwashout underwater concrete should be manufactured largely improving fluidity than the previous one. Thus, the objective of this experimental research is to suggest optimum mix proportions of high fluidity antiwashout underwater concrete. For this purpose, concrete specimens containing ground granulated blast furnace slag were manufactured according to the dosage of antiwashout admixture for unit binder contents of 550 and 600kg/$m^3$, respectively. And then, their quality performances such as slump flow, setting time, underwater segregation resistance, and ratio of compressive strength were evaluated according to the related specification of Korea Concrete Institute. It was observed from the test results that the minimum dosage of antiwashout admixture was necessary to satisfy the related specification.

An Efficient Data Block Replacement and Rearrangement Technique for Hybrid Hard Disk Drive (하이브리드 하드디스크를 위한 효율적인 데이터 블록 교체 및 재배치 기법)

  • Park, Kwang-Hee;Lee, Geun-Hyung;Kim, Deok-Hwan
    • Journal of KIISE:Computing Practices and Letters
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    • v.16 no.1
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    • pp.1-10
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    • 2010
  • Recently heterogeneous storage system such as hybrid hard disk drive (H-HDD) combining flash memory and magnetic disk is launched, according as the read performance of NAND flash memory is enhanced as similar to that of hard disk drive (HDD) and the power consumption of NAND flash memory is reduced less than that of HDD. However, the read and write operations of NAND flash memory are slower than those of rotational disk. Besides, serious overheads are incurred on CPU and main memory in the case that intensive write requests to flash memory are repeatedly occurred. In this paper, we propose the Least Frequently Used-Hot scheme that replaces the data blocks whose reference frequency of read operation is low and update frequency of write operation is high, and the data flushing scheme that rearranges the data blocks into the multi-zone of the rotation disk. Experimental results show that the execution time of the proposed method is 38% faster than those of conventional LRU and LFU block replacement schemes in I/O performance aspect and the proposed method increases the life span of Non-Volatile Cache 40% higher than those of conventional LRU, LFU, FIFO block replacement schemes.

A Study on the Validity of Bamboo-Bundle System and its Improvement - Analysis of the Component Factors of Bamboo-Bundle System - (현행(現行) 죽재결속법(竹材結束法)의 적정분석(適正分析)과 그의 개선(改善) - 결속구성인자(結束構成因子)의 분석(分析)을 중심(中心)으로 -)

  • Lee, Kwang-Nam
    • Journal of Korean Society of Forest Science
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    • v.25 no.1
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    • pp.49-71
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    • 1975
  • The importance of bamboo as raw material for bamboo wares and several kinds of industrial products is highly appreciated at home and abroad. But different kinds of bamboo-bundle systems have been traditionally used in the local areas. There being no reasonable bamboo-bundle system, we have a lot of difficulty in trading bamboo products and executing adrinistmative works. Therefore, a reasonable bamboo-bundle system based on scientific proofs needs to be tested and established for fair trade and administration. This study is carried out to solve the above difficulty with statistical investigation and analysis. The results obtained are as follows. 1. The larger the circles at eye-height become, the more the possibility of the largest internode covering the span between eye-height and 1/4 height increases. 2. The longest internodes are distributed according to a rule without relation to circles at eye-height. 3. The tapering grade of bamboo culms is very high and its form is almost the same without relation to its size. (Form exponent; 0.71-1.05, eye-height form factor; 0.60-0.66, 1/4 becomes, seeing that the circle grade and the percentage of actual volume height form factor; 0.61-0.69). 4. The larger the circles at eye-height are, the lower the percentage of actual volume have negative curve relation to each other. 5. It is considered that the numbers of bamboos bundled in a "Sok" is not decided according to the usefulness of bamboos, judging from the fact that the outputs of bamboo wares per "Sok" in every circle grade are not the same. 6. As the results of the regression analysis, the empirical formulae of several amounts to circles at eye-height and culm length are as follows; Volume, $${\hat{y}}_i=\bar{3}.821874+2.013181log\;C_i+0.839128log\;H_i$$ $$V=0.0066355\;C^{2.013181}\;H^{0.839128}$$ Actual volume, $${\hat{y}}_{ai}=3.915338+0.776549log\;C_i+1.857000log\;H_i$$ $$V_a=0.0082288\;C^{0.776549}\;H^{1.857000}$$ Weight, $$w_i=3.869148+1.936410log\;C_i+0.566904log\;H_i$$ $$W=0.0073986\;G^{1.936410}\;H^{0.565904}$$ 7. Korean Phyllostachys bambusoides Sieb. et Zucc. is almost the same as that of Japan in several amounts, just the same especially in the weight. 8. It is found that the bamboo-bundle systems of Korea and Japan have much closer relation to the weight than other amounts. So It is, therefore, considered that the weight is important factor in deciding bamboo-bundle system. 9. According to the item 8, I should like to propose the appropriate numbers per "Sok" adjusted on the basis of the weight in the Table 18.

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Testing the Reliability of a Smartphone-Based Travel Survey: An Experiment in Seoul (스마트폰 기반 통행 행태 조사 자료 신뢰성 검증: 서울에서 수집된 자료를 바탕으로)

  • Lee, Jae Seung;Zegras, P. Christopher;Zhao, Fang;Kim, Daehee;Kang, Junhee
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.15 no.2
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    • pp.50-62
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    • 2016
  • With programmable applications that utilize sensors, such as global positioning systems and accelerometers, smartphones provide an unprecedented opportunity to collect behavioral data in an unobtrusive and cost-effective manner. This paper assesses the relative accuracy and reliability of the Future Mobility Sensing (FMS), a smartphone-based prompted-recall travel survey. We compared the data extracted from FMS with the data collected from the Korea Passenger Trip Survey (PTS), a traditional self-reported, paper-based travel survey. In total, 46 undergraduate students completed the PTS for seven consecutive days, while also carrying their smartphones with the activated FMS applications for the same time span. After completing the PTS, the participants validated their FMS data on the web-based prompted recall surveys. We then matched the validated FMS data with the PTS-based records. The FMS turns out to be superior in detecting short trips, which are usually under-reported in self-reported travel surveys. The reported PTS travel times are longer than for the FMS, suggesting that participants tend to overestimate their travel time in the PTS. This study contributes to the ongoing development of smartphone-based travel behavior data collecting methods.

Representation of China in Ha Jin's Works and the Controversy over Orientalism (하진의 중국재현과 오리엔탈리즘 논쟁)

  • LEE, Su Mee
    • Cross-Cultural Studies
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    • v.38
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    • pp.191-214
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    • 2015
  • Chinese American Writer, Ha Jin has been writing exclusively about the life in his native Communist China. His stories and poems are almost all about the Chinese people so far. In addition, the distinctive Chinese flavour and the inexorably repressive image of China in his works present an 'Other' to the American culture. Such kind of Chineseness can also be found in Ha Jin's works and his career as a writer. The continued demand for knowledge of China, which is created by China's increasingly important role in the globalized economy, sustains the country's position as an Other for America. In his early four novels, Ha Jin portrays a totally repressive image of Communist China, an image of which functions perfectly as a form of otherness for his American readers. In Ha Jin's portrayal, the Chinese masses are subjected to the Communist authority through its bureaucracy and state-economy mechanism, as well as through the godlike image of Mao Zedong. They are to follow the Communist conscience and subscribe to unity-in-difference. Deviation from the one-party rule is intolerable. In each of the novels, Ha Jin presents a specific system of repression. In In the Pond, confrontation against Party authority is contained by a process of complicity. In Waiting, the Party's power is upheld through a system of surveillance in which people act as agents, resulting in a web of power which paralyses love. The Crazed illustrates a play of power by Party officials which, against the backdrop of the Tiananmen Square Massacre, is full of craze itself, driving people either out of sanity or out of the country. War Trash exposes the Communist power's repression to the extreme by presenting a case of dishonour in those whose life is debased as trash by the Party. The repressive image of China produced in these stories, which span over half a century, makes Ha Jin's China a perfect Other for the West. To sum up, Ha Jin's novels construct a repressive image of China. In his novels, Ha Jin exposes the working of repression in particular systems. Through these systems, he problematizes the notion of personal autonomy for Chinese people and proposes for his western/American readers a solution which eventually turns into a re-presentation of American hegemony.

The Meaning of Dating and Marriage among Well-Educated Korean Couples at the Optimal Marriageable Age (고학력 결혼적령기 커플들의 연애와 결혼에 대한 의미 및 젠더 정체성)

  • Sin, Hye Lim;Joo, Susanna
    • Journal of Family Relations
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    • v.21 no.1
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    • pp.77-98
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    • 2016
  • Objectives: The aim of this study was to explore perceived meanings of dating and marriage among well-educated Korean couples who were in optimal marriageable ages. Particularly, an emphasis was placed on finding out where the traditional gender norms and post-modern contexts intersect on the couples' course of dating and marriage. Method: We undertook a qualitative analysis of 8 couples (age: 26-34) dating. Participants were limited to university graduates of upper-middle rank universities in Seoul, South Korea. The rationale for choosing such sample was based on the idea that characteristics of class is inherent in the act of dating and marriage, and that such characteristics lead to different contextual experiences in dating and marriage. This study was based on interviews conducted over a three-month time span. The interviews were first transcribed into research text and then subjects and key categories were drawn from the transcripts for analysis. Results: Participants sought meanings of joy, learning, and self-improvement in dating, and they were free from traditional gender norms in their romantic relationships. They viewed marriage as having a permanent companionship with their partner, becoming independent from their parents, and/or a social norm to be followed. Participants reported mixed perceptions about marriage in such fashion that they described their parents' relationship in terms of a gendered leader-supporter relationship, while viewing their own relationship as being genderless partners. In transition to parenthood, however, they regressed to traditional gender norms dichotomized as women being a homemaker and men being a breadwinner. In sum, participants displayed expectations that were inconsistent with regard to dating and marriage over the study period. That is, during the course of dating and early marriage, they did not hold separated gender norms; however, when transitioning from being a newly married couple to giving their first childbirth, expectations shifted to traditional gender norms and values. Conclusion: This suggests that it is not marriage, but the experience of childbirth and motherhood, which strengthen traditional gendered norms, engendering regeneration of the gender norms in families. The results indicate that there is a need to promote co-parenting behavior among the newly-married couples and to educate gender equality about parent roles or for parents in South Korea so that they can overcome traditional gendered norms in family.

The Understanding of Folktales for Developmental Approach of Literary Therapy (문학치료의 발달적 접근)

  • Cho, Eun-sang
    • Journal of Korean Classical Literature and Education
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    • no.37
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    • pp.151-184
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    • 2018
  • The purpose of therapeutic approach of humanities, including literary therapy, is ultimately encourage the growth and the development of human being rather than the development of therapeutic techniques for eradicating symptoms. This paper is noteworthy as to the fundamental work for using folktales at therapy sessions. It may be argued that therapy is the process of searching clients' own development history and accepting current challenges in relation to overall context of their own lives and this may lead to the growth clients. In this regard, this paper attempts to set up the selection criteria for folktales to be effectively applied in therapy sessions. The author of the paper argued in her previous paper that folktales may be effective in terms of self-understanding of clients. Folktales can assist clients regarding the objectification of their issues by projecting and exposing their problems. Therefore, this paper argues the method for selecting proper folktales to stimulate of clients" developmental challenges and ultimately to expose them. The first groundwork for this is understand contents of folktale as to general problems of life and view it as the development of one's entire life. The challenge of client is personal and unique but at the same time it is problems of general development process. The author examines the need for developmental approach of literary therapy and attempts to compose a classification framework for understanding folktales as to developmental process. This may use at literary therapy sessions to select proper folktales based on clients' complaining issues and their developmental age. The criteria also can be used as the basis of clients" reaction on folk-tales.

An Empirical Test of the Interactionist Model on the Relationship Between Household Income, Main Caregiver Depression, and Youth Aggression (가구소득, 주양육자 우울, 청소년 공격성 간의 종단적 상호교류관계 검증 : 자기회귀교차지연모델을 이용하여)

  • Kim, Dong Ha;Um, Myung-Yong
    • Korean Journal of Social Welfare Studies
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    • v.47 no.1
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    • pp.151-178
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    • 2016
  • The primary goal of the current study was to investigate the longitudinal relationship between household income, main caregiver depression, and youth aggression from the interactionist perspective. The data were derived by combining the 2006, 2009 and 2012 survey waves from the Korean Welfare Panel Study. This data set covered the full span of adolescence from elementary to high school. The study utilized 561 families as the final sample and conducted autoregressive cross-lagged analysis. As a result, the early income status, main caregiver depression and youth aggression were likely maintained over time. Second, the results provided support for a reciprocal relationship between income and main caregiver depression. On the other hand, the reciprocal relationship between main caregiver depression and youth aggression was not found in the current study. Finally, the mediating effect of main caregiver depression between income and youth aggression was not found in the present study. In conclusion, the results of this study support the interactionist model in that the association between family income and main caregiver depression involves reciprocity and mutual influence across time. These findings have major implications for policy and interventions in regards to low-income families.