• Journal of the Korean Institute of Landscape Architecture
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• v.26 no.2
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• pp.54-61
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• 1998

The subsurface environment of the root zone area can set the stae for "do or die" of the turfgrass plant. The good condition of the greens is verified by their physical properties. Therefore, this study was carried to evaluate on the existing green of Hwasan C.C. by undisturbed soil Core Anaysis. We completed the ISTRC SYSTEM BenchMarking of the undisturbed core samples taken from Green #1, Green #5, Green #9-"Best" area, and Green #9-"Stressed" area for the Hwasan C.C.. It was also our understanding that the greens were in "good" to "very good" conditioni. THe exception might be Green #9-"Stress" area, which was the stressed area. The stressed area was confined to a ridge across Green #9. The organic content test results comfirmed the development of organic layering in depth 0-2.5cm. For the amount of compaction in the upper root zones and te development of the green's respective organic layers, the infiltration rates were high in Green #1, Green #5, and Green #9 "Stressed" area. The depicted aerificaton hole might be the probable cause of the relatively high infiltraton rate. Green #9-"Best" area had a tested infiltration rate of 18.75cm/hr. Either this area had not been aerified, or the undisturbed sample did not contain a aerification cavity. The water retention capacity of the undisturbed samples was good. When the greens were first constructed, the original root zone mix had been relatively low water retention properties. And the bulk density and the porosity of the undisturbed samples were good. In the result, all the greens were similar except for the infiltration. Thus, we supposed that Green #9-"Stressed" area might be ainly influenced by the amount of irrigation water and the configuration of the green's surface. There had been a reduction in the amount of irrigation water as the water retention capacity in the greens was promoted. Especially, it had gradually become more of a problem as the green had matured in Green #9-"Stressed" area. Because Green #9-"Stressed" area was a ridge area. The reduction in the amount of irrigation water might be the probable cause of the stress in Green #9-"Stressed" area. Our final observation related to the soil texture and the particle size distribution of the sand. Though and sand contant of all the tested greens were good, the gravel content of them exceeded ISTRC Guidelines. In particle size distribution of the sand, the very coarse and the coarse content of all the tested greens exceeded, but the rest was insufficient. The stability is a function of the material retained on the 0.25mm mesh screen. But, the content of all the tested greens was very insufficient. Though all the greens was serviceable, the coarse root zone sands, such as the sand in the tested greens, tended to be "unstable". Thus, we recommend using a topdressing/aerification sand which should be more in line with ISTRC/USGA Guidelines.;unstable". Thus, we recommend using a topdressing/aerification sand which should be more in line with ISTRC/USGA Guidelines.ines.

• The Korean Journal of Ecology
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• v.16 no.2
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• pp.191-198
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• 1993

The relationships between microbial activity and disturbance level of soil were investigated from 15 parks in Seoul and undisturbed area. The physico-chemical characteristics of soil and dehydrogenase activity(DHA) as an index of soil microbial activity were analysed. There were ranges of 3.84~7.37 in pH, 9.63~40.33% in moisture content, 3.41~21.49% in organic matter, 0.36~0.79g/g in water holding capacity and 0.03~0.53% in total nitrogen investigated sites. DHA values of soil were 8.64~$146.76{\mu}g/g$ in park soil and 545.14~$1, 198.80{\mu}g/g$ in undisurbed area. DHA of park soil with high traffic density and contamination source from human activities was much lower than that of undisturbed area. DHA was positively correlated with moisture content, organic matter, water holding capacity and total nitrogen.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.10a
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• pp.331-336
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• 1999

A great deal of attention has been given in recent years to large diameter specimen for evaluation of soft soil characteristics, and many studies and developments of the apparatus for obtaining large diameter undisturbed soil samples are in progress attempting to minimize the disturbance of samples for precise strength and consolidation tests in the laboratory. This paper introduces a new large diameter sampler(over 300mm diameter), which can take prefectly undisturbed sampling at any depths applying a new sampling technique. By comparing the results of consolidation tests it is shown that the samples obtained by this new apparatus are of a superior quality to that of samples obtained by conventional sampler(Nx, 75mm dia.) at the same depths.

• Journal of the Earthquake Engineering Society of Korea
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• v.28 no.1
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• pp.67-75
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• 2024

In the case of the Pohang earthquake, which had a magnitude of 5.4 in 2017, geotechnical damages such as liquefaction and ground settlement occurred. The need for countermeasures has emerged, and experimental research in the Pohang area has continued. This study collected undisturbed samples from damaged fine-grained soil areas where ground settlement occurred in Pohang. Cyclic tri-axial tests for identifying the dynamic characteristics of soils were performed on the undisturbed samples, and the results were analyzed to determine the cause of ground settlement. As a result of the study, it was determined that in the case of fine-grained soils, ground settlement occurred because the seismic load as an external force was relatively more significant than the shear resistance of the very soft fine-grained soils, rather than due to an increase in excess pore water pressure.

• Journal of Wetlands Research
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• v.3 no.1
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• pp.1-17
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• 2001

The flora, vegetation structure, distribution of the vascular plants, physico-chemical characteristics of sediment, and nutrient contents of palnts were investigated in the ten disturbed and undisturbed wetlands around the littoral zone of Namgang, Jinju-si, Gyongsangnam-do, Korea from August 7 to August 15 in 1999. 217 taxa of the vascular plants distributed into 2 formas, 26 varieties, 189 species belong to 142 genera under 52 families were sampled or recorded. Dominant species of the undisturbed and the disturbed area were Persicaria thunbergii and Ambrosia artemisiifolia var. elatior, of which importance values were 13.86, and 15.81, respectively. Among 26 species of the naturalized plants, importance value of Ambrosia artemisiifolia var. elatior was highest as 9.54. The ranges of species diversity indices (H') were 1.370~1.819, and highest in the site 1 of the undisturbed area. The ranges of eqitability (J') were 0.779~0.902, and highest in the site 8 of the disturbed area. The ranges of community similarity indices ($CC_s$) were 0.341~0.578 among the ten wetlands, and highest between site 1 and site 2 which were the undisturbed area. The ranges of sediment properties such as pH, conductivity, organic matter, total phosphorus, and total nitrogen were 5.17~7.35, $24.67{\sim}74.33{\mu}mhocm^{-1}$, 1.09~3.82%, 0.0008~0.0034 mg/100g, and 0.06~0.15%, respectively. Nutrient contents of plants such as total nitrogen and total phosphorus were 1.52~2.65% and $0.010{\sim}0.039mg100g^{-1}$, respectively. It was recommended that the establishment of the conservation area was necessary to ensure the habitat for wild life and to maintain the diversity of the vascular hydrophytes and hygrophytes.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.353-356
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• 2002

In this study, the clay samples collected in the area Mokpo carry out laboratory soil test. Under three different curing $temperature-20^{\circ}C,\;50^{\circ}C,\;80^{\circ}C$ and 4 terms of curing day -1day, 7days, 14days, 40days for each, the remolded and reconsolidated samples had been made. To find out an aging effects and geotechnical characteristics between undisturbed samples and reconsolidated samples, laboratory tests were preformed. In the results, it was found that mechanical properties of undisturbed natural samples were similar to high temperature reconsolidation clay. The curing temperature influence on simulating aging effect more than the curing day does and the best curing condition are $80^{\circ}C$, 27days.

• Korean Institute of Interior Design Journal
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• no.2
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• pp.22-28
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• 1994

The restaurant is regarded as the place of association and rest, and is the commercial facilities required the space of delightful and comfortable in mentality as well as the visual satisfaction for the users. The customers have their tendency to avoid the visual and physical contact between the strangers in the restaurant. Therefore, it is required to arrange the undisturbed space from strangers through the appropriate guest seats arrangement by understanding such mental basement. In this study, we have examined the way of space application between the people in the space and the mental mechanism, and we made study and analysis on the conciusness & behavior of the users of the restaurant actually. As the result, the theoretical study was connected to the customers conscious or unconscious behavior and the same results was come out from the paper-and-pencil test and observation research, and its appropriateness was clarifed. To put it briefly , the people have been showing their trends to prefer the place where have a fine view, undisturbed from others and may keep to the private area. On the whole , they prefer the visual variation somewhat rather than the simple, and they are fond of the space of open and comfortable. and also showing that the mental environment could be established by the control of physical environment. Therefore, we can say that the restaurant is required to fulfill this spatial desire of the users through the guest seats arrangement and other visual factors.

• Journal of The Korean Society of Agricultural Engineers
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• v.51 no.5
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• pp.51-58
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• 2009

The total recovery ratio test on undisturbed clay soil sampling in the field and the finite element method analysis on modified static state of penetration process were conducted for the purpose of deciding the most important factor among the shape factors of thin wall tube. The adhesion between tube wall and soil did not decrease although internal clearance ratio of tube increased within the little change of tube area ratio. The most part of disturbance occurred in the tip of sampling tube during the penetration. The longitudinal displacement was larger than the lateral displacement because soil was confined laterally after being entered into tube, and also the longitudinal displacement was larger in the upper part of the sample tube than in the lower part.

• ALGAE
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• v.23 no.3
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• pp.177-186
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• 2008

The present paper consists of 42 taxa belonging to 7 genera of desmids (green algae) collected from two districts of Garhwal region of Uttarakhand (Western Himalayas). The district Haridwar is located 29° 55’to 29° 59’N latitude and 68° 5’to 68° 30’E longitude covering about 2360 km2 area and Dehradun district is situated between 77° 34’to 78° 18’E longitude and 29° 58’to 30° 58’N latitude. Seven genera of desmids are (with number of taxa in parenthesis): Closterium Nitzsch. (9), Cosmarium Corda ex Ralfs (25), Euastrum Ehr. (2), Spondylosium Breb. (1), Micrasterias Ag. (1), Staurastrum Meyen (3), Arthrodesmus Ehr. (1). All these taxa constitute new records for the area. The algal localities are relatively cleaner than those of majority of urban areas. A rich assemblage of desmids shows that water bodies of these hilly areas are still undisturbed and need protection for preservation of algal biodiversity.

• Journal of the Korean Geotechnical Society
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• v.20 no.9
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• pp.155-166
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• 2004

The characteristics of soft clays are very important for the land development plan. This study is to investigate correlations between the engineering properties and the characteristics of clay minerals of the undisturbed clay samples obtained from Sihwa area. This study included X-Ray diffraction analysis, X-Ray fluorescence spectrometer analysis, scanning electron microscopy analysis and energy dispersive X-Ray spectrometer analysis. The correlations between the clay mineral properties and the laboratory and field testing results were investigated. The characteristics of soft clay in Sihwa area were compared with those in Yangsan and Kunsan area.