• Journal of Korean Ophthalmic Optics Society
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• v.15 no.1
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• pp.25-30
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• 2010

Purpose: This study was conducted to estimate the changes of corrected diopter and corrected visual acuity with the change in vertex distance. Also we aimed to provide basic data for refraction test. Methods: Using the trial lens, we measured the corrected diopter and corrected visual acuity after performing binocular balance test. We measured the changes of corrected diopter and corrected visual acuity in change of vertex distance. We analyzed statistical significance and relations between vertex distance and corrected diopter and corrected visual acuity. Results: There was no difference in corrected diopter with the change of vertex distance within -1.00D, but the corrected diopter increased with it over - 1.25D. In particular, the change of diopter was largest when the vertex distance increased 15 mm. At over 11.00D, there was large changes of diopter with the changes of vertex distance at 5 mm, 10 mm and 15 mm. On correlation analysis between the vertex distance and the corrected diopter, there was strong correlation (r=0.999 at 5 mm increase of vertex distance, r=0.982 at 10 mm increase and r=0.957 at 15 mm increase) and also there was significant (p<0.01). At the change of visual acuity in increased of vertex distance, the range of a decrease in visual acuity was large when the changes of vertex distance was largest. On correlation analysis between the vertex distance and the corrected visual acuity, there was strong correlation (r=0.969 at 5 mm increase of vertex distance, r=0.985 at 10 mm increase and r=0.994 at 15 mm increase) and also there was significant (p<0.01). Conclusions: The vertex distance was very important at the refraction test and at wearing spectacle. On correlation analysis between the vertex distance and the corrected diopter, and the corrected visual acuity, there was strong correlation and statistically significant. Therefore, the vertex distance should be kept at the refraction using trial lens, and the best fitting was made not to slipping forward, and so we suggested regular refitting of spectacle and the managing method of spectacle were educated to the spectacle wearers.

• Proceedings of the Korean Geotechical Society Conference
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• 1998.05a
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• pp.35-81
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• 1998

Distinct Element Method(DEM) has a great advantage to model the discontinuous behaviour of jointed rock masses such as rotation, sliding, and separation of rock blocks. Geometrical data of joints by a field monitoring is not enough to model the jointed rock mass though the results of DE analysis for the jointed rock mass is most sensitive to the distributional properties of joints. Also, it is important to use a properly joint law in evaluating the stability of a jointed rock mass because the joint is considered as the contact between blocks in DEM. In this study, a stochastic modelling technique is developed and the dilatant rock joint is numerically modelled in order to consider th geometrical and mechanical properties of joints in DE analysis. The stochastic modelling technique provides a assemblage of rock blocks by reproducing the joint distribution from insufficient joint data. Numerical Modelling of joint dilatancy in a edge-edge contact of DEM enable to consider not only mechanical properties but also various boundary conditions of joint. Preprocess Procedure for a stochastic DE model is composed of a statistical process of raw data of joints, a joint generation, and a block boundary generation. This stochastic DE model is used to analyze the effect of deviations of geometrical joint parameters on .the behaviour of jointed rock masses. This modelling method may be one tool for the consistency of DE analysis because it keeps the objectivity of the numerical model. In the joint constitutive law with a dilatancy, the normal and shear behaviour of a joint are fully coupled due to dilatation. It is easy to quantify the input Parameters used in the joint law from laboratory tests. The boundary effect on the behaviour of a joint is verified from shear tests under CNL and CNS using the numerical model of a single joint. The numerical model developed is applied to jointed rock masses to evaluate the effect of joint dilation on tunnel stability.

• Korean Journal of Food Science and Technology
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• v.37 no.2
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• pp.279-286
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• 2005

Microbial contamination origin of Kimbab was determined using nine types of ready-to-use ingredients, three each from animal, seafood, and vegetable sources. Effect of radiation on microbiological safety was also investigated. Total aerobic bacteria were not detected in seasoned beef, ham, and seasoned burdock, whereas 3.50, 5.41, 8.83, and 5.07 log CFU/g were detected in surimi gel, seasoned and blanched spinach, dried laver, and cucumber, respectively. Total aerobic bacterial and mold numbers were 8.73 and 5.08 log CFU/g in prepared Kimbab. Gamma irradiation reduced level of contaminated aerobic bacteria and mold population in Kimbab and its ingredients, Salmonella mutagenicity assay (Ames test) showed Kimbub ingredients irradiated at 10 kGy did not show any mutagenicity. These results indicate ready-to-use kimbab ingredients were mostly responsible for total aerobic bacteria and mold population of Kimbab, and low dose irradiation and low temperature storage ($10^{\circ}C$) effectively ensured microbiological safety of Kimbab and ready-to-use ingredients.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.1
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• pp.105-116
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• 2017

Murals in villages revitalize communities and spaces, and are economically efficient. Central and local governments are therefore actively undertaking Mural Village Projects but there are some issues and concerns about the projects for the provision of uniformed landscapes for the regions that are the result of a short-term completion of projects, and instead of cohesion, cause destruction of place identities. In addition, the problem of sustainable landscape management that is the result of low community involvement can be pointed out because the murals are products of government-led projects. The study covered the context of landscape and space change processes from a critical perspective, and focused on Ihwa-dong Mural Village, which is considered the first mural village in Korea and has begun to undergo drastic changes due to attention received from media. The purposes of this study are as follows. First, the study provides data about difference of place identity perception and landscape preference between residents and tourists in Ihwa-dong Mural Village. Second, this paper evaluates the current Mural Village Projects and finds alternative directions to improve the projects by using these data. This paper analyzed tourist hot spots in Ihwa-dong Mural Village by using SNS analysis, a field study and focus group interviews. The difference of place identity perception and landscape preference was examined among three groups: residents, new residents who are invited by Mural Village Projects, and tourists. This study showed that many tourists are focused on landscape areas that were not intentionally constructed projects. In addition, the locations of preferred landscapes and stores overlapped. Meanwhile, using qualitative data analysis, it was found that residents perceived the area as being an under-privileged location, while the murals, a non-daily landscape, largely affected place identity perception of new residents and tourists. For landscape preference, tourists preferred outdoor rest areas, while new residents and residents preferred less. Additionally, new residents and tourists preferred an area's night view while residents made no mention of this. Related to the direction of the projects, three groups showed their dependence on the government. This empirical study is significant from a participatory design perspective and in analyzing the issues for mural villages' landscapes, which are spreading across the nation and proceeding without criticism in urban regeneration. Implications for urban planners and suggestions for the future projects are given.

• The Korean Journal of Archival Studies
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• no.23
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• pp.87-139
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• 2010

Unlike in the past, a new paradigm has been presented which the use of records is much more important than the preservation of those in the present. It will be necessary for users to signalizes the value of records and to make themselves easily accessible to records in order that records should be more effectively used. To meet the needs of the times, it is the very 'Contents' that starts to attract public attention. National Archives in England produces and provides contents utilizing multi-media by using digital technology on various sorts of archives which England has. In addition to England, Asian Historical Records center in Japan in Japan makes Archival Contents Service reflecting users' needs and continues to update the latest contents. What is more, National Archives of Korea has recently promoted the introduction of digital archive by the change of archival paradigm in records management, and it is giving an impetus to the development of contents in the digital archive. In fact, it is crucial to keep as many contents as possible and to give service to public, but it will not be possible to get positive response from public and to offer much higher level of archival information service until the quality of contents is highly improved. Accordingly, this manuscript analyzed the feature and type of contents which National Archives of Korea provides with cases of both TNA in England and Asian Historical Records center in Japan, each of which has different characteristics. Also, it dealt with several methods of the usage of contents in those organizations. Furthermore, this study explained what kind of contents and feedback are given to users. Moreover, it divided the components of contents of three institutions as mentioned into three by information provided and evaluated the quality of contents by establishing the details of contents. In addition, there were implications for archives with regard to reference for building contents.

• Ecology and Resilient Infrastructure
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• v.8 no.2
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• pp.79-87
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• 2021

Because active interactions occur among vegetation, hydrology, and geomorphology in riparian systems, any changes in one of these factors can significantly affect the other two. In this study, we evaluated these interactions at four sites (two in Gajeong and two in Hahan) along the Seomjin-gang River that was substantially devastated by an extreme flood in 2020. We examined the relationship between the riparian vegetation and the hydraulic characteristics of the flood using remote sensing, hydraulic modeling, and field surveys combined. The evaluation results showed that the floods caused a record-breaking rise of up to 43.1 m above sea level at the Yeseong-bridge stage gauge station (zero elevation 27.4 m) located between the Gajeong and Hahan sites, with the shear stress being four times higher in Hahan than in Gajeong. Additionally, the water level during the flood was estimated to be a maximum of 1 m higher depending on the location in the presence of riparian plants. Furthermore, both sites underwent extensive biological damage due to the flood, with 78-80% loss in vegetation, with preferential damage observed in large willow species, compared to Quercus acutissima. The above findings imply that all plant species exhibit different vulnerabilities towards extreme floods and do not induce similar behavior towards events causing a disturbance. In conclusion, we developed strategies for effectively managing riparian trees by minimizing flood hazards that could inevitably cause damage.

• Pediatric Infection and Vaccine
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• v.10 no.2
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• pp.153-158
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• 2003

Purpose : The incidence of hepatitis B virus infection has gradually decreased since 1983 when hepatitis B vaccine was firstly produced. This study was performed to evaluate the efficacy of hepatitis B immunization. Methods : The elementary, middle and high school children in Incheon area were enrolled in this study in 1997 and 1998. Hepatitis B virus surface antigen(HBsAg) was measured using reversed passive hemagglutination(RPHA). Results : The results were as follows The positive rates of HBsAg in elementary, middle and high school children were 0.7%(337/46,861), 2.5%(381/15,026) and 3.1%(681/21,938) respectively in 1997 and 0.6%(257/41,946), 2.7%(379/13,652) and 2.4%(628/25,277) respectively in 1998. The positive rates of HBsAg in children under 19 years of age in 1985, 1990 and 1995 were 6.1, 5.2 and 3.5% respectively. Conclusion : The positive rates of HBsAg in elementary school children in 1997 and 1998 has decreased compared with those of the previous studies. The majority of elementary school children were given hepatitis B vaccination. These results suggest that hepatitis B vaccines used in Korea were effective for prevention of hepatitis B infection in school children.

• Korean Journal of Environmental Agriculture
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• v.18 no.1
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• pp.77-82
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• 1999

Three floating islands have been constructed for water quality improvement for a polluted irrigation reservoir. Each floating island consists of 10 segments. Each segment hay an area of $16m^2$(4×4m) and is made of wood frames and floats(polystyrene foam). We planted three species of aquatic macrophytes(Typha angustifolia, Zizania latifolia, and Phragmites australis) in floating island on June, 1998. They grew very well without death. We would like to evaluate Phragmites australis is the most suitable aquatic macrophyte that could be planted in a floating island because it maintained the best balance of its root and shoot among them. During their grown period, net primary productivity of Typha angustifolia was $962gDM/m^2$, Zizania latifolia was $1,115gDM/m^2$, and Phragmites australis was $523gDM/m^2$. From these data, it would be estimated to 5.0Kg uptake of nitrogen by aquatic macrophytes and phosphorus 0.8Kg in 3 floating islands. The floating islands worked well as a habitat of fish and prawns. Many kinds of insect lived on the floating islands. The floating island has not only the function of water quality treatment but also several advantages: improvement of landscape and species diversity; low cost of maintenance; low technology; unnecessary of energy; less susceptible to variations in pollutant loading. It could be evaluated a good measure of water quality improvement for an irrigation reservoir. However, it should be intensively studied to develop more light, strong, durable and low-priced frames for efficient floating islands.

• Korean Journal of Heritage: History & Science
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• v.46 no.1
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• pp.268-289
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• 2013

The Dinosaur tracksite at Jeori, Geumseongmyeon, Euiseonggun, Gyeongsangbukdo, Korea (National Monument No. 373) has been studied in the aspects of location, stratigraphy, sedimentology, fossil occurrence, unique geological records, literature, significance in natural history, preservation, and management. On the basis of these features, the Jeori tracksite has been assessed semiquantitavely. The Jeori tracksite occurs in the Sagok Formation (Albian) of the Euiseong sub-basin, and over 300 footprints forming 12 sauropod trackways, 10 ornithopod trackways, and 1 theropod trackways are preserved in this tracksite. The track-bearing deposits consist of tabular-bedded medium- to fine-grained arkose with mudstone drape, interlaminated fine-grained sandstone to siltstone and mudstone, and shaly mudstone. The dinosaur tracks are preserved in the interlaminated fine-grained sandstone to siltstone and mudstone, and most of them are observed as underprints. The track-bearing deposits are interpreted as sheetflood deposits on the floodplain under a seasonal paleoclimatic condition with alternating of wetting and drying periods. Multiple tension fractures with NE strike were formed in the track-bearing bed, which resulted in that tracks seem to occur in several horizons. The significance in natural history of the tracksite can be summarized as follows: 1) the historical implication of the Jeori tracksite as the firstly designated National Monument of dinosaur fossil sites, 2) the high density of the occurrence of diverse footprints (over 300) within small area (about $1,600m^2$), and 3) the significance of the tension fractures associated with the track-bearing bed as geoeducational records for the understanding the development of fault. In order to share the value of the Jeori tracksite in the aspect of natural history with the community and public, the interpretive panel should be modified to include figures explaining paleoenvironment and tension fault development. In addition it is recommended that a brochure be published briefly explaining the tracksite and to educate the residents about the natural and social significance of the tracksite. For the safety of visitors it would be desirable for the road in front of the tracksite to be moved at least 10 m southward, which could mitigate the shaking of the track bed caused by traffic.

• Journal of Food Hygiene and Safety
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• v.37 no.6
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• pp.400-410
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• 2022

This study was performed to analyze the microbial contamination levels of three non-heated rice cake manufacturers in terms of seasonal manufacturing process and to investigate the effects of summertime soaking on contamination levels and temperature-controlled soaking in water on reduction in microbial levels. The total aerobic bacteria (TAB) ranged from 2.69 log CFU/g to 5.08 log CFU/g in the produce, but the microbial contamination increased sharply during soaking. The levels of TAB and coliforms during summer soaking were 7.01 and 3.96 log CFU/g, respectively, and this was significantly higher than those in other seasons. The contamination level was high in the subsequent freezing, with the TAB level (6.24 log CFU/g) exceeding the legal standard. The temperature of soaking water in summer increased from 19.1℃ to 26.8℃ after 12 h of soaking. The microbial contamination was significantly high commensurate with increased soaking time, and the TAB level in the frozen process exceeded the legal standard from 9 h of soaking. The use of ice packs to prevent the increase in temperature of the soaking water in summer resulted in maintenance of temperature at 20.1℃ for up to 12 h. The average TAB value in the freezing process was 4.42 log CFU/g after 12 h of soaking, and this is 1.77 log CFU/g lower than that before. Based on these results, it was determined that controlling the soaking time and water temperature are essential for the production of a safe unheated frozen rice cake. The safety of the HACCP system could be established by applying these preventive management standards.