• Clinical and Experimental Pediatrics
• /
• v.49 no.6
• /
• pp.653-658
• /
• 2006

Purpose : Because voiding cystourethrography(VCUG) is an invasive method, we studied whether VCUG could be postponed through evaluation of alternative non-invasive tests including renal ultrasonography and $^{99m}Tc$-DMSA renal scan. Methods : We reviewed the medical records of 175 patients initially diagnosed with febrile urinary tract infection during the one year period of 1999, and compared 3-tests : renal ultrasongraphy, $^{99m}Tc$-DMSA renal scan, and VCUG. Results : Renal ultrasonography didn't contribute to the prognostication of pyelonephritis(photopenic areas) or vesicoureteral reflux(VUR). Presentation of photopenic areas in $^{99m}Tc$-DMSA renal scan was related to VUR. If both findings of renal ultrasonography and $^{99m}Tc$-DMSA renal scans were normal, this condition was closely related to normal results in VCUG. And if both examinations were abnormal, the condition was closely related to VUR. But this state could not always guarantee the normal result from VCUG because of low sensitivity in finding VUR. Conclusion : In cases in which acute phyelonephritis is demonstrated by $^{99m}Tc$-DMSA renal scan, VCUG is required. In addition to this, if the conditions of hydronephrosis, vesicoureteral dilatation, increases of renal volume, and changes of echogenesity are shown by renal ultrasonography, VCUG should be performed. If a patient has difficulty undergoing VCUG, temporary postponement of VCUG can be taken into consideration, but only in cases where both examinations of renal ultrasonography and $^{99m}Tc$-DMSA renal scan are normal. Nevertheless, close observation is be advised even in this case.

• Journal of Korean Neurosurgical Society
• /
• v.30 no.3
• /
• pp.272-277
• /
• 2001

Objective : Polymethylmethacrylate(PMMA) is often used to reconstruct the spine after total corpectomy, but the exothermic curing of liquid PMMA poses a risk of thermal injury to the spinal cord. The purposes of this study are to analyze the heat blocking effect of pre-polymerized PMMA sheet in the corpectomy model and to establish the minimal thickness of PMMA sheet to protect the spinal cord from the thermal injury during PMMA cementation of vertebral body. Materials & Methods : An experimental fixture was fabricated with dimensions similar to those of a T12 corpectomy defect. Sixty milliliters of liquid PMMA were poured into the fixture, and temperature recordings were obtained at the center of the curing PMMA mass and on the undersurface(representing the spinal cord surface) of a prepolymerized PMMA sheet of variable thickness(group 1 : 0mm, group 2 : 5mm, or group 3 : 8mm). Six replicates were tested for each barrier thickness group. Results : Consistent temperatures($106.8{\pm}3.9^{\circ}C$) at center of the curing PMMA mass in eighteen experiments confirmed the reproducibility of the experimental fixture. Peak temperatures on the spinal cord surface were $47.3^{\circ}C$ in group 2, and $43.3^{\circ}C$ in group 3, compared with $60.0^{\circ}C$ in group 1(p<0.00005). So pre-polymerized PMMA provided statistically significant protection from heat transfer. The difference of peak temperature between theoretical and experimental value was less than 1%, while the predicted time was within 35% of experimental values. The data from the theoretical model indicate that a 10mm barrier of PMMA should protect the spinal cord from temperatures greater than $39^{\circ}C$(the threshold for thermal injury in the spinal cord). Conclusion : These results suggest that pre-polymerized PMMA sheet of 10mm thickness may protect the spinal cord from the thermal injury during PMMA reconstruction of vertebral body.

• Korean Journal of Heritage: History & Science
• /
• v.48 no.3
• /
• pp.4-29
• /
• 2015

To protect cultural heritages from damage and destruction, evaluating the crime prevention environments is considered extremely important. This study analyzed the crime patterns related to cultural heritages, classified the crime environments by their types, and deduced the elements of the CPTED(Crime Prevention Through Environment Design), aiming to present the indices for evaluating the crime prevention environments. The results of this study can be summarized as follows. First, the crimes related to cultural heritages that must be prevented were identified as the night time trespassing and arson. According to the results of the analysis of external environments based on crime actions, the crime prevention environments of cultural heritages were classified into 10 types. Second, the important evaluation principles of the cultural heritage CPTED were the access control, surveillance reinforcement and the surrounding environment. Third, the access control that cover the internal region, boundary, external region and surroundings were classified into 22 indices. The surveillance reinforcement covers natural, organized and mechanical surveillance with 21 indices. Fourth, the applicability of the CPTED evaluation index was presented according to the types of the cultural crime prevention environments. The results confirmed that the maximum 43 indices were applicable to the seowon(lecture hall), hyanggyo(Confucian school), and gwana(district government office), and the minimum 10 indices, to the ramparts. Finally, the 43 indices were applied to Donam Seowon to validate their applicability. The results confirmed that most of the indices were applicable with the partial supplements. The evaluation index presented in this study is likely to contribute to studies in the cultural heritage CPTED field and to the protection of cultural heritages. Furthermore, this study is considered significant because it unleashed continuous concerns on and developments of CPTED. However, as the field survey to validate the applicability of the indices was limited to only one type, it may require further objective verification such as through an expert's examination of the validity and applicability of the evaluation index. In addition, to accommodate the index in related policies and systems, more precise verifications of the indices by type are considered necessary.

• Journal of Environmental Impact Assessment
• /
• v.28 no.2
• /
• pp.101-112
• /
• 2019

Over the last few years, air pollution ($PM_{10}$, $PM_{2.5}$) in the Seoul metropolitan area (SMA) has emerged as one of the most concerned and threatening environmental issues among the residents. It brings about various harmful effects on human health, as well as ecosystem and industrial activities. Governments and individuals pay various costs to mitigate the level of air pollutants. This study aims to empirically find the willingness to pays (WTP) among the parents from different socio-cultural groups - international and domestic groups to mitigate air pollution ($PM_{10}$, $PM_{2.5}$) in their residential area. Contingent Valuation Methods (CVM) is used with employing single-bounded dichotomous choice technique to elicit the respondent's WTP. Using tobit (censored regression) and probit models, the monthly mean WTP of the pooled sample for green electricity which contributes to improve air quality in the region was estimated as 3,993 KRW (3.58 USD). However, the mean WTP between the international group and domestic group through a sub-sample analysis shows broad distinction as 3,325KRW (2.98 USD) and 4,449 KRW (3.98 USD) respectively. This is because that socio-cultural characteristics of each group such as socio-economic status, personal experience, trust in institutions and worldview are differently associated with the WTP. Based on the results, the society needs to raise awareness of lay people to find a strong linkage between the current PM issue and green electricity. Also, it needs to improve trust in the government's pollution abatement policy to mobilize more assertive participation of the people from different socio-cultural background.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.23 no.1
• /
• pp.89-104
• /
• 2021

Based on the TF-IDF weighted value that evaluates the importance of words that play a key role, the semantic network analysis(SNA) was conducted on the self-introduction letter of freshman at Korea National College of Agriculture and Fisheries(KNCAF) in 2020. The top three words calculated by TF-IDF weights were agriculture, mathematics, study (Q. 1), clubs, plants, friends (Q. 2), friends, clubs, opinions, (Q. 3), mushrooms, insects, and fathers (Q. 4). In the relationship between words, the words with high betweenness centrality are reason, high school, attending (Q. 1), garbage, high school, school (Q. 2), importance, misunderstanding, completion (Q.3), processing, feed, and farmhouse (Q. 4). The words with high degree centrality are high school, inquiry, grades (Q. 1), garbage, cleanup, class time (Q. 2), opinion, meetings, volunteer activities (Q.3), processing, space, and practice (Q. 4). The combination of words with high frequency of simultaneous appearances, that is, high correlation, appeared as 'certification - acquisition', 'problem - solution', 'science - life', and 'misunderstanding - concession'. In cluster analysis, the number of clusters obtained by the height of cluster dendrogram was 2(Q.1), 4(Q.2, 4) and 5(Q. 3). At this time, the cohesion in Cluster was high and the heterogeneity between Clusters was clearly shown.

• Korean Journal of Environment and Ecology
• /
• v.35 no.6
• /
• pp.594-600
• /
• 2021

The purpose of this study is to observe the period of mating calls of cicadas in South Korea to identify the emergence period and geographic distribution for each cicada species. The study sites were 19 protection areas nationwide. The mating calls of cicadas were collected over the 12 months of 2019. A bioacoustics measuring device was installed to record the mating calls of cicadas in WAV, 44,100Hz format for 1 minute every hour. The temperature was recorded once or twice every hour using a micro-meteorological measuring device. Nine species of Korean cicadinae were studied. The start and end periods of mating calls were recorded for each cicada species for the subsequent analysis. The analysis results showed that nine cicada species appeared in the 19 protection areas. The chronological order of mating call periods for each species was as follows: Cryptotympana atrata (7/12 - 9/30), Meimuna opalifera (7/27 - 10/20), Hyalessa fuscata (7/25 - 10/9), Graptopsaltria nigrofuscata (7/28 - 9/5), Platypleura kaempferi (7/3 - 9/29), Suisha coreana (9/14 - 10/30), Leptosemia takanonis (6/26 - 8/2), Auritibicen intermedius (7/27 - 9/28), and Meimuna mongolica (8/8 - 9/11). The mating call period was between 35 (Meimuna mongolica) and 89 (Platypleura kaempferi) days, with the average being 62 days. The elevation above sea level for the habitats of each species was as follows: 5 - 386 m for Cryptotympana atrata, 7 - 759 m for Meimuna opalifera, 7 - 967 m for Hyalessa fuscata, 42 - 700m for Graptopsaltria nigrofuscata, 7 - 700 m for Platypleura kaempferi, 5 - 759 m for Suisha coreana, 7 - 759 m for Leptosemia takanonis, 397 - 967 m for Auritibicen intermedius, and 7 - 42 m for Meimuna mongolica. The average temperature of the habitats of each species was as follows: 23.9℃ for Cryptotympana atrata, 21.8℃ for Meimuna opalifera, 22℃ for Hyalessa fuscata, 23℃ for Graptopsaltria nigrofuscata, 22.9℃ for Platypleura kaempferi, 14.6℃ for Suisha coreana, 20.6℃ for Leptosemia takanonis, 19.3℃ for Auritibicen intermedius, and 24.4℃ for Meimuna mongolica. In terms of the habitat distribution of species, Meimuna opalifera, Hyalessa fuscata, and Platypleura kaempferi were distributed in more than 15 protection sites. Cryptotympana atrata was distributed in the lowlands in the southwest. Graptopsaltria nigrofuscata was distributed in the western area of the Korean Peninsula. Suisha coreana was distributed in areas excluding high mountain areas and parts of the southeast area. Leptosemia takanonis was distributed in areas near the mountains. Auritibicen intermedius was distributed locally in the high mountain areas. Meimuna mongolica was distributed locally in flat wetlands.

• Economic and Environmental Geology
• /
• v.56 no.4
• /
• pp.457-473
• /
• 2023

Asbestos has been produced, imported and used in various industries in Korea over the past decades. Since asbestos causes fatal diseases such as malignant mesothelioma and lung cancer, the use of asbestos has been generally banned in Korea since 2009. However, there are still many asbestos-containing materials around us, and safe management is urgently needed. This study aims to examine asbestos-related trend changes using major asbestos-related keywords based on the asbestos trend analysis using big data for the past 32 years (1991 to 2022) in Korea. In addition, we reviewed both domestic trends related to the production, import, and use of asbestos before 1990 and asbestos-related policies from 2023 to 2027. From 1991 to 2000, main keywords related to asbestos were research, workers, carcinogens, and the environment because the carcinogenicity of asbestos was highlighted due to domestic production, import, and use of asbestos. From 2001 to 2010, the main keywords related to asbestos were lung cancer, litigation, carcinogens, exposure, and companies because lawsuits were initiated in the US and Japan in relation to carcinogenicity due to asbestos. From 2011 to 2020, the high ranking keywords related to asbestos were carcinogen, baseball field, school, slate, building, and abandoned asbestos mine due to the seriousness of the asbestos problem in Korea. From 2021 to present (2023), the main search keywords related to asbestos such as school, slate (asbestos cement), buildings, landscape stone, environmental impact assessment, apartment, and cement appeared.

• Journal of Korean Society of Forest Science
• /
• v.112 no.4
• /
• pp.561-573
• /
• 2023

National forests have an advantage over private forests in terms of higher investment in capital, technology, and labor, allowing for more intensive management. As such, national forests are expected to serve not only as a strategic reserve of forest resources to address the long-term demand for timber but also to stably perform various essential forest functions demanded by society. However, most forest stands in the current national forests belong to the fourth age class or above, indicating an imminent timber harvesting period amid an imbalanced age class structure. Therefore, if timber harvesting is not conducted based on systematic management planning, it will become difficult to ensure the continuity of the national forests' diverse functions. This study was conducted to determine the optimal volume of timber production in the national forests to improve the age-class structure while sustainably maintaining their economic and public functions. To achieve this, the study first identified areas within the national forests suitable for timber production. Subsequently, a forest management planning model was developed using multi-objective linear programming, taking into account both the national forests' economic role and their public benefits. The findings suggest that approximately 488,000 hectares within the national forests are suitable for timber production. By focusing on management of these areas, it is possible to not only improve the age-class distribution but also to sustainably uphold the forests' public benefits. Furthermore, the potential volume of timber production from the national forests for the next 100 years would be around 2 million m³ per year, constituting about 44% of the annual domestic timber supply.

• Korean Journal of Environment and Ecology
• /
• v.37 no.5
• /
• pp.327-336
• /
• 2023

This study aimed to propose an effective method for surveying wild birds by comparing the results of bioacoustic detection with those obtained through a field survey. The study sites were located at Dongbaek-dongsan and a 1100-altitude wetland in Jeju-do, South Korea. The bioacoustic detection was conducted over the course of 12 months in 2020. For the bioacoustic detection, a Song-meter SM4 device was installed at each study site, recording bird songs in 1-min per hour, .wav, and 44,100 Hz format. The findings of the field survey were taken from the 「Long-term trends of Bird Community at Dongbaekdongsan and 1100-Highland Wetland of Jeju Island, South Korea.」 by Banjade et al. (2019). The results of this study are as follows. First, the avifauna identified using bioacoustic detection comprised 29 families and 46 species in Dongbaek-dongsan, and 16 families and 25 species in the 1100-altitude wetland. Second, based on the song frequency, the dominant species in Dongbaek-dongsan were Hypsipetes amaurotis (Brown-eared Bulbul, 33.62%), Horornis diphone (Japanese Bush Warbler, 12.13%), and Zosterops japonicus (Warbling White-eye, 9.77%). In the 1100-altitude wetland the dominant species were Corvus macrorhynchos (Large-billed Crow, 27.34%), H. diphone (19.43%), and H. amaurotis (16.56%). Third, in the field survey conducted at Dongbaek-dongsan, the number of detected bird species was 39 in 2009, 51 in 2012, 35 in 2015, and 45 in 2018, while the bioacoustic detection identified 46 species. In the field survey conducted in the 1100-altitude wetland, the number of detected bird species was 37 in 2009, 42 in 2012, 34 in 2015, and 38 in 2018, while the bioacoustics detection identified 25 species. Overall, 43.6% of the 78 species detected in the field survey in Dongbaek-dongsan (34 species) were identified using bioacoustic detection, and 38.3% of the 47 species detected in the field survey in the 1100-altitude wetland (18 species) were identified using bioacoustic detection. Fourth, the bioacoustic detection identified 9 families and 12 species of birds in Dongbaek-dongsan, and 3 families and 7 species of birds in the 1100-altitude wetland. No results from field survey were available for these species. The identified birds were predominantly nocturnal, including Otus sunia (Oriental Scops Owl) and Ninox japonica (Northern Boobook), passage migrants, including Larvivora cyane (Siberian Blue Robin), L. sibilans (Rufous-tailed Robin), and winter visitors with a relatively small number of visiting individuals, such as Bombycilla garrulus (Bohemian Waxwing) and Loxia curvirostra (Red Crossbill). Fifth, the birds detected in the field survey but not through bioacoustic detection included 18 families and 48 species in Dongbaek-dongsan and 14 families and 27 species in the 1100-altitude wetland; the most representative families were Ardeidae, Accipitridae, and Muscicapidae. This study is significant as it provides essential data supporting the possibility of an effective survey combining bioacoustic detection with field studies, given the increasing use of bioacoustic devices in ornithological studies in South Korea.

• Korean Journal of Environment and Ecology
• /
• v.38 no.2
• /
• pp.204-216
• /
• 2024

Understanding the trade-off effect in ecosystem services and measuring the interrelationships between services are crucial for managing limited environmental resources. Accordingly, in this study, we identified the dominant trends and increases and decreases in ecosystem services derived from changes in land cover over about 30 years and tracked changes in the relationships between ecosystem services that occurred over time. Through it, we determined the relationship between land cover changes and ecosystem service changes, as well as the distinct characteristics of service changes in different areas. The research primarily utilized the InVEST model, an ecosystem service assessment model. After standardizing the evaluation results between 0 and 1, it went through principal component analysis, a dimensionality reduction technique, to observe the time-series changes and understand the relationships between the services. According to the research results, the area of urbanized regions dramatically increased between 1989 and 2019, while forests showed a significant increase between 2009 and 2019. Between 1989 and 2019, the national ecosystem service supply witnessed a 13.9% decrease in water supply, a 10.5% decrease in nitrogen retention, a 2.6% increase in phosphorus retention, a 0.9% decrease in carbon storage, a 1.2% increase in air purification, and a 3.4% decrease in habitat quality. Over the past 30 years, South Korea experienced an increase in urbanized areas, a decrease in agricultural land, and an increase in forests, resulting in a trade-off effect between phosphorus retention and habitat quality. This study concluded that South Korea's environment management policies contribute to improving ecosystem quality, which has declined due to urbanization, and maximizing ecosystem services. These findings can help policymakers establish and implement forestry policies focusing on sustainable environmental conservation and ecosystem service provision.