• Journal of Environmental Impact Assessment
• /
• v.25 no.6
• /
• pp.384-401
• /
• 2016

The vegetation assessment indicator has been developed recently as a biological part of the integrated assessment system for river environment to improve the efficiency of river restoration projects. This study carried out to test the vegetation assessment indicator and to reset its grade criteria on experimental streams. We classified and mapped vegetation communities at the level of physiognomic-floristic composition by each assessment unit. A total of 204 sampling quadrats were set up on the 68 assessment units at 5 experimental streams. By analyzing the vegetation data collected, we examined the appropriate numbers of sampling quadrats, the criteria of vegetation index score, classification of vegetation community, and grade criteria for vegetation assessment. The developed vegetation assessment indicator composed with the vegetation complexity index (VCI), the vegetation diversity index (VDI), and the vegetation naturalness index (VNI) was proved to reflect the current conditions of the streams sufficiently. The contribution of vegetation naturalness index to grading by vegetation assessment indicator was larger, but three indexes were closely correlated to each other. Also there was more clearer discrimination of grading with the application of adjusted criteria of vegetation assessment indicator and the standardized classification of vegetation community, but the stream segment type did not influence the vegetation assessment grade significantly.

• Journal of Conservation Science
• /
• v.36 no.2
• /
• pp.112-122
• /
• 2020

The purpose of this study was to find out the correlation through comparative analysis of used materials and manufacturing techniques such as firing characteristics for sherds excavated from celadon kiln site in Punggil-ri, Jangheung. The color difference of the sherds was very wide, and even in the microstructure of the cross section of the glaze layer and the body layer, the celadons, whitewares, blackware, and stonewares could not be characterized because they did not show distinct differences from each other. As a result of estimating the firing temperature through the analysis of constituent minerals and thermal analysis, most of them were estimated to have been fired at 1000℃, but some were fired at high temperatures above 1200℃. It was difficult to clearly distinguish between celadon and whiteware even in the major compositional content of bodies. In the statistical analysis, glaze could be classified three group according to the type of sherds, but the bodies of celadons, whitewares, and blackware classified into one similar group. It is considered that it is not more likely differences in raw materials but some ingredients were removed or added during the purification process. Conclusionally, in this kiln site was found through scientific analysis that there were technical attempts to produce various ceramics, and that the manufacturing techniques and materials of ceramics were in an early stage that was not stabilized.

• Journal of Astronomy and Space Sciences
• /
• v.25 no.3
• /
• pp.299-320
• /
• 2008

We study on the astronomical calendars that was used in the Silla era. The calendars are deduced from the records in Samguksagi. They were influenced from calendaric system of Tang Dynasty, which are Lin duk calendar(麟德曆), Ta yen calendar(大衍曆) and Sun myung calendar(宣明曆). We analyse them in detail according to the time and duration of use. Water clock system of Unified Silla was used four water vessels for supplying water. We found the model from documents on ancient water clock that are appeared in the old Korean, Chinese and Japanese historical records. We have assumed the model of Unified Silla clepsydra is similar type with Chinese records during Tang dynasty and with Japanese reconstructed water clock in Temple Asoka. After fluid dynamic experiment, we decide the suitable diameter of supplying pipe and volume of the vessels used in the clepsydra. We introduce the experimental instruments and methods for accomplishing the clock. We designed and reconstructed the water clock of Unified Silla and float rods for measuring time, that is based on the Silla's calendaric system.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.43 no.6
• /
• pp.127-137
• /
• 2015

Recent research has shown that university students experience severe stress and depleted directed attention due to study, social relationships, and economic dependency. Based on the stress reduction theory and the attention restoration theory, this study aims to investigate the effects of natural landscape on university students' stress and cognitive performance through a wide array of measurements including GSR(galvanic skin responsse), IBI(interbeat interval), ZIPERS(Zucherman Inventory of Personal Reactions), and mental arithmetic test. The restorative effects of natural landscape were compared with those of urban landscape. 128 university students participated in the study, and the data of 120 students was analyzed. The results showed that natural landscape was more restorative in relieving psychological stress and in enhancing cognitive performance than urban landscape, which evidenced the restorative effects of natural landscape. Therefore, it could be proposed that natural landscaping of the university campus contributes to students' stress reduction and cognitive enhancement. But such effects were not found in the two physiological measures(both GSR and IBI). Moreover, it was analyzed that urban landscape had a more beneficial effect than natural landscape for IBI, which might resulted from the participants' characteristics and the study landscape. Specifically, the young age span of the participants(average 23.8 years old) and the very natural setting of the university where they were enrolled might lead to the conflicting results in physiological measures. Also, the urban landscape used in the study had a sense of "scope", which is one of the Kaplan and Kaplan's restorative characteristics. Based on this opinion, it was suggested that future study should investigate the impact of the landscape type and contents as well as the participants' characteristics on the restorative effects of natural landscape.

• Journal of Microbiology and Biotechnology
• /
• v.23 no.11
• /
• pp.1500-1508
• /
• 2013

Ebosin, a novel exopolysaccharide produced by Streptomyces sp. 139, has obvious antirheumatic arthritis activity in vivo, and its biosynthesis gene cluster (ste), consisting of 27 open reading frames, has been identified. This paper reports our study of the gene functionality of ste8, the predicted protein product of which is homologous to some bacterial chain length determinant Wzz proteins. For characterization of Ste8, ste8 was cloned and expressed in the mutant strain E. coli 086:H2 (${\Delta}wzz$). The functional complementation of wzz by ste8 was demonstrated by the restoration of wild-type lipopolysaccharide biosynthesis and increased levels of serum resistance of E. coli 086:H2 (${\Delta}wzz$) (pET30a-ste8). To examine the function of ste8 in ebosin biosynthesis, the gene was knocked out with a double crossover via homologous recombination. The molecular weight of the ebosin derivative EPS-8m produced by the mutant Streptomyces sp. 139 ($ste8^-$) was much lower than that of ebosin, and the binding activity of EPS-8m for IL-1R decreased significantly compared with ebosin. These results demonstrate that ste8 encodes a chain length determinant (Wzz) that functions in ebosin biosynthesis.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.32 no.4
• /
• pp.324-331
• /
• 2010

The radial forearm free flap (RFFF) has become a workhorse flap as a means of reconstructing surgical defects in the head and neck region. We have transferred 12 RFFFs with fasciocutaneous type on oral cavity defects in 12 patients after cancer resection and submucous fibrotic lesion ablation from 2005 to 2007 at Department of oral and maxillofacial surgery, Pusan National University Hospital. We reviewed retrospectively patients' charts and followed up the patients. Clinical analysis on the cases with RFFFs focusing on flap morbidity, indications and available vessels was done. The results of study are follows: 1. RFFF could be applied for all kind of defects after resection of tongue, floor of mouth, buccal mucosa, denuded bone of palate, maxilla, and mandible. 2. All free flaps could be used for primary reconstruction. The survival rate of 12 RFFFs was 92%. Partial marginal loss of the flaps was shown as 3 cases among 12 cases. Large size-vessels like superior thyroid artery, facial artery, internal jugular vein were favorable for microvascular anastomosis. 3. Parenteral nutrition instead of nasal L-tube also can be favorable for postoperative a week for better healing of the flap if the patients couldn't be tolerable with nasal tubing. 4. Donor sites with thigh skin graft were repaired with wrist band for 2 weeks. The complications included scarring, abnormal sensation on hand, and reduced grip strength in few patients, but those didn't induce major side effects. 5. Most RFFFs were well healed even if mortality rate of cancer patients was shown as 50% (5/10 persons). The mortality of patients was not correlated with morbidity of the flaps. We could identify the usefulness of RFFF for restoration of oral function, esthetics if the flap design, tissue transfer indications, and well controlled operation are proceeded.

• The Journal of Korean Academy of Prosthodontics
• /
• v.46 no.6
• /
• pp.561-568
• /
• 2008

STATEMENT OF PROBLEM: Currently, many implant systems are developed and divided into two types according to their joint connection: external or internal connection. Regardless of the connection type, screw loosening is the biggest problem in implant-supported restoration. PURPOSE: The purpose of this study is to assess the difference in stability of abutment screws between the external and internal hexagonal connection types under cyclic loading. MATERIAL AND METHODS: Each of the 15 samples of external implants and internal abutments were tightened to 30 N/cm with a digital torque gauge, and cemented with a hemispherical metal cap. Each unit was then mounted in a $30^{\circ}$ inclined jig. Then each group was divided into 2 sub-groups based on different periods of cyclic loading with the loading machine (30 N/ cm - 300 N/cm,14 Hz: first group $1{\times}10^6$, $5{\times}10^6$ cyclic loading; second group $3{\times}10^6$, $3{\times}10^6$ for a total cyclic loading of $6{\times}10^6$) The removal torque value of the screw before and after cyclic loading was checked. SPSS statistical software for Windows was used for statistical analysis. Group means were calculated and compared by ANOVA, independent t-test, and paired t-test with ${\alpha}$=0.05. RESULTS: In the external hexagonal connection, the difference between the removal torque value of the abutment screw before loading, the value after $1{\tims}10^6$ cyclic loading, and the value after $1{\times}10^6$, and additional $5{\times}10^6$ cyclic loading was not significant. The difference between the removal torque value after $3{\times}10^6$ cyclic loading and after $3{\times}10^6$, and additional $3{\times}10^6$ cyclic loading was not significant. In the internal hexagonal connection, the difference between the removal torque value before loading and the value after $1{\times}10^6$ cyclic loading was not significant, but the value after $1{\times}10^6$, and additional $5{\times}10^6$ cyclic loading was reduced and the difference was significant (P < .05). In addition, in the internal hexagonal connection, the difference between the removal torque value after $3{\times}10^6$ cyclic loading and the value after $3{\times}10^6$, and additional $3{\times}10^6$ cyclic loading was not significant. CONCLUSION: The external hexagonal connection was more stable than the internal hexagonal connection after $1{\times}10^6$, and additional $5{\times}10^6$ cyclic loading (t = 10.834, P < .001). There was no significant difference between the two systems after $3{\times}10^6$, and additional $3{\times}10^6$ cycles.

• Journal of Preventive Medicine and Public Health
• /
• v.29 no.2 s.53
• /
• pp.347-357
• /
• 1996

Although occupational low back pain accounts for $20\sim40%$ of all occupational illness and injury, there are limited numbers of studies regarding the effectiveness of back school program. The objective of this study was to evaluate the economic benefit of back school program for early return to work of occupational low back pain patients in the current occupational injury compensation and management system. The cost-benefit analysis in this study was conducted to evaluate the relative magnitude of benefit to cost. The total cost was estimated by calculating the value of components in back school program according to governmental budget protocol. The back school program was consisted of three major approaches, pain center, work-hardening program and funcional restoration program and each of components had various facilities and experts. The total amount of cost was estimated as 250,866,220 won per year. The most promising type of back school program were quite intensive (a 3 to 5-week stay in a specialized center), therefore, if we adopted the 5-week stay course, 10 courses could be held in a year. Following to the medical act, 20 patients per doctor could participate in a each course, ie, total 200 patients in a year. As a result, we could estimate the cost of 1,254,331 won a patient. We estimated the benefit by using data of a few local labor offices about average medical treatment beneficiary and off-duty beneficiary of 46 occupational low back pain patients in 1994. Ullman and Larsson (1977) mentioned that the group of chronic low back pain patients who participated in back school program needed less time to recover by 48.4% of beneficiary duration. And in the trying to estimate the benefit, we asked 10 rehabilitation board certificate doctors about reduction proportion of treatment cost by introducing back school program. The answered reduction proportions were in the range of $30\sim45%$, average 39%. As a final result, we could see that the introduction of back school program in treatment of chronic occupational low back pain patients could produce the benefit to cost ratio as 3.90 and 6.28. And we could conclude that the introduction of back school program was beneficial to current occupational injury compensation and management system.

• Korean Journal of Plant Taxonomy
• /
• v.43 no.4
• /
• pp.274-284
• /
• 2013

This study presents a survey on the bryophytes in Dongbaek-dongsan located at Seonheul Gotjawal on the north-eastern face of Mt. Halla in Jeju Island, Korea. A total of 85 taxa belonging to the Bryophyta (22 families 44 genera 62 species), Marchantiophyta (12 families 16 genera 23 species) were found. Among them, 3 moss species, Diphyscium perminutum Takaki, Racomitrium japonicum Dozy & Molk., and Isopterygium minutirameum (M$\ddot{u}$. Hal.) A. Jaeger. were new additions to the bryophyte flora of Korea. The liverwort index was 27.0%. Predominant life-form was weft. The rates for the bryophytes dominating in mesic to hygric sites were higher than for the bryophytes mainly observed in xeric habitats. We considered that the composition and distribution of species are affected by the different environmental factors according to the evergreen broad-leaved forests, wetlands and exposed spaces. Moreover, the rocks were the substrate type that play a major role in providing the micro-habitats for bryophytes in this area. Particularly, the bryophytes of swamps in this area were very unique and various for its limited space and showed plant communities with mosaic spatial pattern, along with vascular plants. We suggest more detailed and comprehensive studies on the swamps where endemic fern Mankyua chejuense B. -Y. Sun, M. H. Kim & C. H. Kim inhabits to provide valuable information for the conservation and restoration of the species and habitats.

• The Journal of the Acoustical Society of Korea
• /
• v.37 no.5
• /
• pp.378-386
• /
• 2018

The present paper suggests the original form of the bell pavilion for the King Song-Dok bell which is one of the precious national treasure of Korea. In order to this, many literatures were reviewed including both historical and acoustical references. As the results, the model of the bell pavilion for the King Song-Dok bell is suggested as follows considering acoustical characteristics of the King Song-Dok bell and the traditional Korean bells ; 1) The bell pavilion has the rumbling puddle beneath the bell on the ground floor for resonance of sound 2) Many lumbers are used for columns and beams rather than boards since natural frequencies of the bell are 64 Hz and 168 Hz so that the sound absorption of the low frequency sound may not be occurred. 3) Only some boards may be used for the area between upper and middle molding of lintel in order to prevent of direct sunlight and sea breeze since this type of structure were used for bell pavilion of the same age. 4) Square form with the odd number of 3 or 5 Kans is adopted for bell pavilion considering the weight and the size of the bell which had been used traditionally 5) Finally, half-hipped structure is used for the roof of the bell pavilion which was the predominant form of the age.