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A Feasibility Study on the Use of Liner and Cover Materials Using Sewage Sludge (하수슬러지의 차수재 및 복토재로의 이용타당성에 관한 연구)

  • 유남재;김영길;박병수;정하익
    • Journal of the Korean Geotechnical Society
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    • v.15 no.2
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    • pp.43-71
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    • 1999
  • This research is an experimental work of developing a construction material using municipal wastewater sludge as liner and cover materials for waste disposal landfill. Weathered granite soil and flyash, produced as a by-product in the power plant, were used as the primary additives to improve geotechnical engineering properties of sludge. For secondary additives, bentonite and cement were mixed with sludge to decrease the permeability and to increase the shear strength, respectively. Various laboratory test required to evaluate the design criteria for liner and cover materials, were carried out by changing the mixing ratio of sludge with the additives. Basic soil properties such as specific gravity, grain size distribution, liquid and plastic limits were measured to analyze their effects on permeability, compaction, compressibility and shear strength properties of mixtures. Laboratory compaction tests were conducted to find the maximum dry densities and the optimum moisture contents of mixtures, and their effectiveness of compaction in field was consequently evaluated. Permeability tests of variable heads with compacted samples, and the stress-controlled consolidation tests with measuring permeabilities of samples during consolidation process were performed to obtain permeability, and to find the compressibility as well as consolidational coefficients of mixtures, respectively. To evaluate the long term stability of sludges, creep tests were also conducted in parallel with permeability tests of variable heads. On the other hand, for the compacted sludge decomposed for a month, permeability tests were carried out to investigate the effect of decomposition of organic matters in sludges on its permeability. Direct shear tests were performed to evaluate the shear strength parameters of mixed sludge with weathered granite, flyash and bentonite. For the mixture of sludge with cement, unconfined compression tests were carried out to find their strength with varying mixing ratio and curing time. On the other hand, CBR tests for compacted specimen were also conducted to evaluate the trafficability of mixtures. Various test results with mixtures were assessed to evaluate whether their properties meet the requirements as liner and cover materials in waste disposal landfill.

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An Evaluation of NURI(New University for Regional Innovation): Focusing on Changes in Graduate Employment (졸업생 취업률 변화를 중심으로 본 지방대학혁신역량강화(NURI)사업의 평가)

  • Lee, Sam-Ho;Kim, Hisam
    • KDI Journal of Economic Policy
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    • v.30 no.2
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    • pp.157-183
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    • 2008
  • 'New Universities for Regional Innovation(NURI)' is a financial aid program designed to promote the development of universities as a major component of Regional Innovation System (RIS). In particular, this program emphasizes the role of regional universities to provide the qualified graduates for the regional economy. This paper is to evaluate the effect of NURI, focusing on the change of graduates' employment. The effect of the program can be evaluated by the quality of graduates' accumulated human capital, and graduates' employment performance represents the graduates' quality evaluated in the labor market. This is also believed to be a good performance indicator of the NURI program. We utilize the graduate employment survey of Korean Educational Development Institute (KEDI), and calculate the graduates' employment rates of the departments that received the financial support of NURI (treatment group). We also calculate the graduates' employment rates of the departments that applied for the support of the NURI program but were not selected (comparison group). By using difference-in-differences method, we compare the change of graduates' employment rates in treatment and comparison groups before and after the program came in effect. Compared with the employment rates in 2004 before the NURI program started, the graduates employment rates improved in both groups in 2005 and 2006. The improvement of the employment rates in the treatment group is larger than that in the comparison group. Moreover, the difference of improvement gets larger in the year 2006 than in 2005, which means those students who were affected more years by the NURI program are more likely to be employed. However, the difference is not statistically significant, and we cannot definetely conclude that NURI showed the desired effect on the quality of the college graduates. We calculate employment rates in two ways; whether to treat going on to graduate education as an employment or not. The result was qualitatively the same in both cases. We also tracked quality of employment by investigating the firm size where the graduates of the treatment group were employed. By utilizing data from the Employment Insurance Fund, we measure the firm size by the number of employees. We did not find any deterioration of employment quality between 2005 and 2006, though it deteriorates in 2007. Therefore, the improvement of employment rates until 2006, though not statistically significant, does not seem to come at the cost of employment quality. The interpretation of this result cannot help being very limited. First, this evaluation covers such a short time period. It only covers two years after the program started, 2005 and 2006. Second, the extent of the improvement in employment rates is not satisfactory considering the amount of financial support, even though it can be argued that the employment has improved since the inception of the program. Subsequent evaluation of the program is required to certify the NURI programs' longer term effectiveness.

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The Effects of Salt and Temperature on Changes of Adenosine Triphosphate Related Compounds and Free Amino Acids in Makerel Muscle during Storage (고등어 저장중 염분농도와 저장온도에 따른 Adenosine Triphosphate 관련물질 및 유리아미노산의 변화)

  • 우경자;원등금차
    • Journal of the East Asian Society of Dietary Life
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    • v.6 no.1
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    • pp.93-103
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    • 1996
  • The effects of salt and temperature on changes of K value, IMP, free amino acids and histamine concentration in Makerel muscle during storage were examined. The content of salt was 0, 3, 5 and 10% and storage temperature was at 0, 8, 16 and 2$0^{\circ}C$. 1. Content of IMP was 607.3mg% In raw material and as storage temperature was decreased and as salt content was increased, the rate of decrease in IMP was slow. 2. K value of raw material was 14% and rapidly increased as temperature increased and salt content decreased. 3. The time required to reach at 50% in K value was 13.6-16.6 days at $0^{\circ}C$ and 1.4-3.3 days at 2$0^{\circ}C$ in 0-10% salt content. 4. Except taurine and histidine, the contents of all free amino acids were slowly increased during storage at $0^{\circ}C$ and in high salt content but at 2$0^{\circ}C$ and in 0% salt they were more rapidly increased. The contents of Ala., Glu., Val.., Leu., Lys., and NH$_3$ were rapidly increased than the contents of Phe., Gly. and Ile. 5. Taurine and histidine were rapidly decreased at high temperature and in 0% salt during storage. 6. The storage condition which produced more than 100mg% in histamine was 3 days at 16$^{\circ}C$(180mg%) and 2$0^{\circ}C$(443.5mg%) in 0% salt and was 10days (163.1mg) at 16$^{\circ}C$ in 3% salt.

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Characterization of a new commercial strain 'Goni' by intra-specific hyphal anastomosis in Pleurotus ostreatus (계통간 교잡에 의한 백색느타리 품종 '고니'의 육성 및 그 특성)

  • Yoo, Young Bok;Lee, Sang Cheol;Kim, Eun Jung;Kong, Won Sik;Jang, Kab Yeul;Shin, Pyung Gyun
    • Journal of Mushroom
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    • v.7 no.3
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    • pp.130-134
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    • 2009
  • To develop new white variety of Oyster mushroom, all white varieties which have been collected and kept in the lab were revived and screened their cultural characteristics. 84 intra-specific Oyster mushroom hybrids between the white-colored mutants Suhan and Wonhyeong were developed using hyphal anastomosis technique in 2007. The Po2007-63 ($2842-7{\times}0205-7$) was shown the best cultural characteristics, selected to be a new variety and named as 'Goni'. The new commercial strain, 'Goni' has white pilei and grows well under spring and autumn conditions in Korea. The fruiting bodies of 'Goni' are of an excellent quality in that not only the stipe is thick and long but also the pileus is small and hard. The optimum temperatures for mycelial growth and fruiting body development were $25-30^{\circ}C$ and $10-16^{\circ}C$, respectively. Time period required for the initiation of the first fruiting body is about 3 to 5 days depending on the temperatures. The shape of fruiting body is thin funnel shape. Fruiting body production per bottle was about $91{\pm}13$ g which is almost 97% quantity compared to that of other variety 'Miso'. Relatively low temperature incubation ($11^{\circ}C$) resulted in the development of better quality of 'Goni' mushrooms. When two different media including potato dextrose medium and mushroom complete medium were compared, the growth of mushroom were much faster in mushroom complete medium at $20-25^{\circ}C$, but not at $25^{\circ}C$. Similar results were observed with other variety 'Miso'. Analysis of the genetic characteristics of the new commercial strain 'Goni' showed a major DNA profile as that of the parental Suhan when primer URP 1 was used, but different to 'Miso' that was used as a control. When screens were performed with primer URP 2, DNA patterns were similar both to that of the parents and 'Miso'. This new variety of the white Oyster mushroom has a clean and fresh image that corresponds well to "health food". We therefore expect that this new strain will satisfy the consumers demand for variety and excellent mushrooms.

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Feature Analysis of Metadata Schemas for Records Management and Archives from the Viewpoint of Records Lifecycle (기록 생애주기 관점에서 본 기록관리 메타데이터 표준의 특징 분석)

  • Baek, Jae-Eun;Sugimoto, Shigeo
    • Journal of Korean Society of Archives and Records Management
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    • v.10 no.2
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    • pp.75-99
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    • 2010
  • Digital resources are widely used in our modern society. However, we are facing fundamental problems to maintain and preserve digital resources over time. Several standard methods for preserving digital resources have been developed and are in use. It is widely recognized that metadata is one of the most important components for digital archiving and preservation. There are many metadata standards for archiving and preservation of digital resources, where each standard has its own feature in accordance with its primary application. This means that each schema has to be appropriately selected and tailored in accordance with a particular application. And, in some cases, those schemas are combined in a larger frame work and container metadata such as the DCMI application framework and METS. There are many metadata standards for archives of digital resources. We used the following metadata standards in this study for the feature analysis me metadata standards - AGLS Metadata which is defined to improve search of both digital resources and non-digital resources, ISAD(G) which is a commonly used standard for archives, EAD which is well used for digital archives, OAIS which defines a metadata framework for preserving digital objects, and PREMIS which is designed primarily for preservation of digital resources. In addition, we extracted attributes from the decision tree defined for digital preservation process by Digital Preservation Coalition (DPC) and compared the set of attributes with these metadata standards. This paper shows the features of these metadata standards obtained through the feature analysis based on the records lifecycle model. The features are shown in a single frame work which makes it easy to relate the tasks in the lifecycle to metadata elements of these standards. As a result of the detailed analysis of the metadata elements, we clarified the features of the standards from the viewpoint of relationships between the elements and the lifecycle stages. Mapping between metadata schemas is often required in the long-term preservation process because different schemes are used in the records lifecycle. Therefore, it is crucial to build a unified framework to enhance interoperability of these schemes. This study presents a basis for the interoperability of different metadata schemas used in digital archiving and preservation.

Quality characteristics of farm-made brown rice vinegar via traditional static fermentation (전통정치배양에 의한 농가형 현미식초의 품질특성)

  • Baek, Chang Ho;Jeong, Da-Hee;Baek, Seong Yeol;Choi, Ji-Ho;Park, Hye-Young;Choi, Han Seok;Jeong, Seok-Tae;Kim, Jae Hyun;Jeong, Yong-Jin;Kwon, Joong-Ho;Yeo, Soo-Hwan
    • Food Science and Preservation
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    • v.20 no.4
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    • pp.564-572
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    • 2013
  • We investigated the quality characteristics of brewing brown rice vinegar through a traditional static fermentation process. Accordingly, we decided to compare the physicochemical characteristics of brewing vinegar at different temperatures and filtration methods. In four to five weeks' time, the acetic acid fermentation exhibited the highest titratable acidity and then it eventually decreased. The titratable acidity was affected by the filtration method. It was revealed that the titratable acidity was higher in the forced filtration than the traditional filtration method. Various organic acids were detected in order to initialize the fermentation stage and as the fermentation progressed, only the acetic acid could be detected. The total free amino acid content was higher at a temperature of $30^{\circ}C$ than at $20^{\circ}C$. Moreover, the free amino acid content was dependent on the acetate content during the acetic fermentation process. The main bioactive substance of the ${\gamma}$-aminobutyric acid content was more than twice at a fermentation temperature of $30^{\circ}C$ compared to the fermentation temperature of $20^{\circ}C$. Furthermore, the total amino acid and essential amino acid content at a temperature of $30^{\circ}C$ was excellent. The quality of the brown rice vinegar via forced filtration method at a temperature of $30^{\circ}C$ was the most excellent. Based on these results, the fermentation temperature and the use of nuruks (fermenting agent) affected the quality of the brown rice vinegar, and an appropriate method to consider its purpose is required.

Temperature-dependent Development Model of the Striped Fruit Fly, Bactrocera scutellata (Hendel)(Diptera: Tephritidae) (호박꽃과실파리 온도 발육모형)

  • Jeon, Sung-Wook;Cho, Myoung-Rae;Kim, Yang-Pyo;Lee, Sang-Guei;Kim, So-Hyung;Yu, Jin;Lee, Jong-Jin;Hwang, Chang-Yeon
    • Korean journal of applied entomology
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    • v.50 no.4
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    • pp.373-378
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    • 2011
  • The striped fruit fly, Bactrocera scutellata, damages pumpkin and other cucurbitaceous plants. The developmental period of each stage was measured at seven constant temperatures (15, 18, 21, 24, 27, 30, and $33{\pm}1.0^{\circ}C$). The developmental time of eggs ranged from 4.2 days at $15^{\circ}C$ to 0.9 days at $33^{\circ}C$. The developmental period of larvae was 4.2 days at $15^{\circ}C$, and slowed in temperatures above $27^{\circ}C$. The developmental period of pupa was 21.5 days at $15^{\circ}C$ and 7.6 days at $33^{\circ}C$. The mortality of eggs was 17.1% at $15^{\circ}C$ and 22.9% at $33^{\circ}C$, Larval mortalities (1st, 2nd, 3rd) were 24.1, 27.3 and 18.2%, respectively, at $15^{\circ}C$, Pupal mortalities were 18.2% at $15^{\circ}C$ and 23.1% at $33^{\circ}C$. The relationship between developmental rate and temperature fit both a linear model and a nonlinear model. The lower threshold temperatures of eggs, larvae, and pupae were 12.5, 10.7, and $6.3^{\circ}C$, respectively, and threshold temperature of the total immature period was $8.5^{\circ}C$. The thermal constants required to complete the egg, larval, and pupal stages were 33.2, 118.3, and 181.2 DD, respectively. The distribution of each development stages was described by a 3-parameter Weibull function.

A Study on The Consumer Expectation - Performance according to the Types of Internet Shopping Malls (인터넷 쇼핑몰 유형에 따른 소비자 기대-성과에 관한 연구)

  • Lee, In-Ku;Ryoo, Hak-Soo
    • Korean Business Review
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    • v.17 no.2
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    • pp.63-87
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    • 2004
  • To create and maintain comparative supremacy as a strategic tool of business, many organizations have introduced informational technology and system. By using this system, Some companies got a beneficial value for achieving organizational goals but others could not obtain their effectiveness and efficiency. In particular, a lot of organizations that tried to make strategic supremacy with e-commercial trade are under hard condition because of poor profit. It implies that it is essential to identify and analyse the consumer who uses e-commercial trade. This paper, therefore, focusing on internet shopping malls between business and consumer as one of areas of e-commercial trades, shows the difference between consumer expectation and performance. The results of this study are as follows: First, as for the significant difference of influencing factors to consumer satisfactions according to the types of internet shopping malls, there is a meaningful difference in consumer anxiety and internet usefulness, but not in consumer service. Prior to verify the differences in detail on consumer's anxiety and internet usefulness, we examined that there is any difference between expectation and performance. T-test was used for the variants of consumer anxiety and internet usefulness, and its meaningful probability was 0.000, which means that both showed statistically significant difference. Based on the results, we also found that regardless of the types of internet shopping malls, consumer expectation was greater than performance. although the difference between expectation and performance was not equal according to the internet shopping malls. Second, a regression analysis was performed to understand the relation between consumer service, internet usefulness, consumer anxiety, and consumer satisfaction, it was found that consumer service, internet usefulness, consumer anxiety had significantly effected on consumer satisfaction. Third, To verify the relation between consumer satisfaction and repurchase-intentions, intentions to spread out, Pearson correlation analysis was used. it was found that consumer satisfaction had positive effect on both intentions. This study has some limitations because of the shorts of money and time. since the sample of this study was consumers who have ever bought one or more products via internet shopping mall, this sample was appropriate. but the major parts of sample were college students, and the sample size was so small. therefore this results should carefully be generalized. For further study, it is required to select more precise samples and to include more variables.

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Study on the Influence of Waterbirds Distribution According to the Restoration of Intertidal Zone (조간대 복원이 수조류의 분포에 미치는 영향)

  • Park, Chi-Young;Shin, Man-Seok;Kim, Ho-Joon;Paek, Woon-Kee;Lee, Joon-Woo
    • Korean Journal of Environment and Ecology
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    • v.30 no.5
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    • pp.837-847
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    • 2016
  • In this study, the bird fauna of Sihwa Lake in Gyeonggi Province were investigated from 2009 to 2014 to identify the effect of the restored intertidal zone on bird community. Based upon the analysis of the habitat status and distribution change of water birds in the intertidal zone, the following conclusions were obtained. The number of water bird individuals increased by approx. 40 thousand after the restoration. Most of water bird species increased, but diving ducks decreased. Analysis of the number of individuals of water birds before and after the intertidal zone restoration showed that there was a significant increase in the number of shorebird individuals. There is a habitat use pattern change in the southern tideland intertidal zone that includes the largest area of widened intertidal zone and the inland waters of the intertidal zone. This is related to the change of benthic ecosystem which is the food source of birds. The benthic ecosystem in restoring Sihwa Lake has been stabilized with a decrease in opportunistic species and consistent increase in equilibrium species that are sensitive to pollution. As a result, the environmental conditions for shorebirds have been improved. The restoration of intertidal zone affected the habitat use and distribution patterns of water birds in a short period of time. Compared to before restoration, all the water birds now use the wide area of the intertidal zone with no partiality and it is confirmed that the restoration greatly affected the distribution of shorebirds and swan & geese. This study was conduced to identify the effects of an artificial restoration of intertidal zone due to tidal power generation of bird species. In terms of maintaining and improving biodiversity, the intertidal zone restoration was recognized to be important and still shows positive results. This study is expected to provide a direction when an alternative is required to maintain and improve biodiversity in a similar situation in the future.

Trends in Colorectal Cancer Incidence in Daejeon and Chungcheongnam-do, South Korea (2000-2012) (대전광역시와 충청남도의 13년간(2000-2012) 대장암 발생 추세)

  • Kim, Soon-Young;Kweon, In-Sun;Kim, Jung-A;Lee, Tae-Yong;Nam, Hae-Sung
    • Journal of agricultural medicine and community health
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    • v.40 no.3
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    • pp.115-125
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    • 2015
  • Objectives: Colorectal cancer is one of the major cancers in South Korea. We described the time trends in colorectal cancer incidence in Daejeon, a metropolitan city, and Chungcheongnam-do (Chungnam), a rural province, South Korea. Methods: Using the databases from the Daejeon Cancer Registry (DCR) and the Chungnam Cancer Registry (CCR), age-standardized (to world standard population) rates for incidence (ASRW) were calculated. Average annual percent change (AAPC) was assessed as a trend indicator. The completeness (such as the mortality/incidence ratio) and validity (such as the death certificate only %, microscopic verification %, primary site uncertain %, and age unknown %) were analyzed to examine the data quality of DCR and CCR. Results: Incidence of colorectal cancer showed increasing trend in both sexes. Over the years 2000-2012 in Daejeon, ASRW was increased significantly from 37.2 to 51.7 per 100,000 person-years (AAPC, 3.9%) among men and from 17.1 to 28.4 (AAPC, 3.9%) among women, respectively. In Chungnam, ASRW was also increased from 29.8 to 50.1 per 100,000 person-years (AAPC, 5.1%) among men and from 15.9 to 26.6 (AAPC, 3.2%) among women, respectively. The AAPC for colon cancer was greater than rectal cancer in both Daejeon and Chungnam. The trend of rectal cancer incidence was differ by sex (AAPC in men vs women, 2.7% vs 1.7% in Daejeon; 3.5% vs 0.8% in Chungnam). Indices of completeness and validity showed that the quality control of DCR and CCR was adequate to describe the trends of ASRW. Conclusions: Both Daejeon and Chungnam have had a rapid increase in colorectal cancer incidence. Monitoring and intervention are required on the risk factors which may contribute to this trend.