• Journal of Korean Society of Forest Science
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• v.39 no.1
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• pp.64-68
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• 1978

Thirty nine clones of ${\times}$Populus alba glandulosa were selected tentatively and planted in Hwasung in Kyunggi-do, Jinju in Kyungnam-do, Myongju in Kangweon-do. Height measurements after tree growing seasons, indicated significant differences between clones and locations. Interaction between clones and locations were not significant statistically. Among 39 clones, 65-29-19, 65-11-106, 67-47-10, 66-14-149, 64-6-44 were best performing clones. Height measurements in Hwasung Kyunggi, and Jinju Kyungnam were 3.83m, 4.02m respectively, while that in Myongju Kangweon was only 1.06m. Myongju plantation in Kangweon-do is located in altitude of 800m and its average annual temperature was $6.2^{\circ}C$. Retarded growth in this plantation is caused high altitude and low temperature of the plantation which resulted from nearly three monthes shorter growing period than two other plantations. It is also recommended that straightness of stem, branching, wood quality and insect and disease-resistance have to be considered as selection criteria along with growth performance.

• Journal of Korean Society of Steel Construction
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• v.12 no.5 s.48
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• pp.495-502
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• 2000

In this study, the wind tunnel test for Kwangju World Cup Stadium with long span roof was carried out and its results were considered in the two roofs: one is the case of one roof, and the other is the case of two roofs which are identical. In this experiment, a 1/400-scale model was used. As a result of measuring wind pressure in the case of one roof and then two, when two roofs are set up, wind load for structural frame decreases by 35%, compared to that of one roof. These results show that the current criteria for wind loadings, which specify that wind pressure on the roof depends only on the altitude, have limitations for adoption, and a wind tunnel test is essential to design.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.6
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• pp.73-83
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• 2015

The objective of this study is to establish implications for forest restoration planning in North Korea by analyzing spatio-temporal forest changes and detecting bio-physical factors driving forest degraded. We measured the relationship and spatial distribution between shifting cultivation and sparse forest. We also analyzed between degraded forest land and ecological variables by binary logistic regression to find biophysical drivers of forest degradation and deforestation in North Korea. Between the sparse forest and the shifting cultivation, a positive relationship is found (r=0.91) and scattered discontinuously throughout the country (Moran's I = -1, Z score = -13.46 (p=0.000)). The sparse forest showed a negative relationship with the warmest month(bio 9), the coldest month(bio10), and the minimum of soil water contents (swc_min), while the shifting cultivation had a negative relationship with the warmest month(bio 9) and the minimum of soil water contents(swc_min). However, the most critical drivers convert forests into sloping farmland were the three months rainfall in summer(bio8) and the yearly mean of soil water contents. Such results reflect the growth period of crops which overlaps with the rainy season in North Korea and the recent land reclamation of uplands where the soil water contents are maintained with a dense forest. When South Korea aids forest restoration projects in North Korea, in consideration of food shortage due to North Korea's cropland deficiency, terrace farmlands where soil water contents can be maintained should be excluded from the priority restoration area. In addition, an evaluation method for selecting a potential restoration area must be modified and applied based on multiple criteria including altitude and socio-economic factors in the respective regions.

• Journal of Mushroom
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• v.16 no.2
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• pp.65-69
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• 2018

Mushrooms growing spontaneously in the Juwangsan National Park were surveyed from April to October 2017 for supporting management of higher fungi and creating a bio-diversity database of the park. In total, two divisions, eight classes, 21 orders, 85 families, 225 genera, and 503 species were detected. Among them, 247 species belonged to order Agaricales, which occupied 48.8% of the population, followed by members of orders Polyporales and Russulales. The mushrooms were abundant in August, and an altitude of 300-400 m above sea level was optimal for their growth, such as those found at Sanguijigu, Deajeonsa, and Geodaeri semgoal areas. Furthermore, Macrolepiota procera and Sarcodon aspratus, which belong to criteria of climate change, were detected in this survey.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.8 no.4
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• pp.43-51
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• 2005

Due to rapid and reckless economic development, natural resources of the national land have been damaged and polluted. Accordingly, the necessity for environment-friendly development has been on the rise and many have made efforts to assess the environmental value of the national land. This study divides the conservation areas by means of using relative elevation, slope, and development of housing land based on environmental evaluation of the national land. The relative elevation is obtained by the difference of altitude at the edge of the forest patch extracted from the land cover classification map based on the ridgeline, and the slope is obtained by environment-oriented land suitability analysis. The development of housing land is classified in accordance with the progress of each project. Twenty-six evaluation criteria are divided into five different grades using the minimal indicator approach and then sub-divided into ten grades by means of using the following two scenarios. The first one uses the weight of input materials while the second one relies on the size of patches that are emphasized in landscape ecology. Consequently, such a study demonstrated the following results. The method relying on the weight of input materials revealed the limitation of emphasizing input materials excessively, whereas the method of considering the size of patches resulted in the division of conservation areas that embody regional characteristics. This study is meaningful in that it classifies the conservation areas by reflecting the regional characteristics and the ecological values of animals and plants.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.441-447
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• 2002

KSR-III(Korea Sounding Rocket - III), which is being developed by Space Technology R&D Division of KARI(Korea Aerospace Research Institute) will be launched in late 2002. It is a three-stage, liquid propellant rocket which can reach 250 km altitude and will carry out observation of ozone layer and scientific experiments, such as microgravity experiment, and atmospheric measurement. KSR-III is believed to be an intermediate to the launch vehicle capable of carrying a satellite to its orbit. Space Test Department of KARI performed GVT(Ground Vibration Test) fer KSR-III EM at Rocket Test Building of KARI. GVT is very important for predicting the behavior of rocket in its operation, developing flight control program and performing aerodynamic analysis. This paper gives an introduction of rocket GVT configuration and information on test procedures, techniques and results of It. In this test. to simulate free-free condition, test object hung in the air laterally by 4 bungee cords specially devised. For the excitation of test object, pure random signal by two electromagnetic shakers was used and total 22 frequency response functions were achieved. Polyreference parameter estimation was performed to identify the modal parameters with MIMO(Multi-Input-Multi-Output) method. As the result of the test, low frequency mode shapes and modal parameters below 60Hz were identified

• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.4
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• pp.41-49
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• 2012

The objective of this study is to investigate the characteristics of the location and prospects of the bear shelves built by Asiatic black bears in the Jirisan National Park. Previous researchers have been analyzed bear shelves in terms of places for resting and eating, but we are going to analyze based on the prospect-and-refuge theory. Characteristics of the sites of bear shelves are measured through field survey and topographic analysis by using digital elevation model (DEM). The normalized difference vegetation index (NDVI) is used to evaluate the optimum location of bear shelves in terms of crown density. Man-made objects are identified by viewshed analysis based on geographical information system (GIS). Findings of this paper can be summarized as follows. First, most bear trees are located deep inside of the mountainous national park, slopes of 30~40 degrees, altitude of 400~1,200m, and relatively low vegetation density with NDVI value of 0.4~0.6 compared to the average NDVI of the park. Second, the average height of bear shelves is 12.44m, or 74% of the average height of bear trees. They are located at suitable places to observe nearby trails and other park facilities. Third, man-made objects within the 100m radius of bear trees include lodge, bear training center, beekeeping camp, and hiking trails. Thus we may temporarily conclude that one of the main criteria of the bear tree selection in the park has been to identify optimum places for the monitoring of human activities in their habitat.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.7B
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• pp.719-726
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• 2002

In WRC-2000, Resolution 734 was adopted to study the use of high altitude platform station(HAPS) operating in the bands above 30GHz. Therefore, frequency sharing feasibility between a new HAPS systems and an existing terrestrial fixed-service(FS) system should be analyzed primarily. In this paper, interference effects from the HAPS system into the radio-relay station are analyzed in terms of two cases; one is the interference distribution from the power-flux density(PFD) of HAPS airships, and the other the interference power from the ground stations. In conclusion, the new PFD criteria different from the exiting satellite system should be required, and the coordinated distance between the HAPS nadir and the radio-relay station should be 60km ∼ 253km for P$\sub$HG/ = -50dBW/MHz of transmitting power spectral density to share the new HAPS system into the existing FS system.

• Korean Journal of Environment and Ecology
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• v.29 no.2
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• pp.250-262
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• 2015

This study aims to investigate the characteristics of the vegetation structure in the sectin stretching between the Jilmoi wetlands and the Donghae Observatory and to set the criteria for the basic data for a management plan including restoration afterwards. 12 plots($10m{\times}40m$, $20m{\times}20m$) were set up to analyse the vegetation structure. The analysis of the classification by TWINSPAN and ordination by DCA, importance percentage and property, distribution of diameter of breast height, growth increments of major woody species, species diversity and the physicochemical properties of soil were all analyzed. Vegetation classes were divided into 3 communities, which are community I (Pinus densiflora community), community II (Quercus mongolica community) and community III (Quercus mongolica-Tilia amurensis community). The P. densiflora community declined when competing with Q. mongolica and Fraxinus rhynchophylla and Q. mongolica competed with T. amurensis on an understory layer in Q. mongolica community. Q. mongolica competed with T. amurensis on both canopy and understory layers in Q. mongolica-T. amurensis community. P. densiflora declined and it was assumed to succeed to F. rhynchophylla or T. amurensis through Q. mongolica based on the importance percentage and distribution of the diameter of the breast height of small and middle sized trees. The age of P. densiflora was between 47 to 51 years old and Q. mongolica was 61years old. T. amurensis was 61 years old and the growth of Q. mongolica slowed a little. As the result of Shannon's index of species diversity, community I ranged from 0.9578 to 1.1862, community II ranged from 0.7904 to 1.2286 and community III ranged from 0.8701 to 1.0323. The contents of organic matter and cation were low compared to uncultivated mountain soil and it were analysed to be inappropriate for tree growth.

• Journal of the Korean Institute of Landscape Architecture
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• v.29 no.1
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• pp.80-91
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• 2001

The purpose of this research is to provide a basic knowledge to open up for undeveloped park in process of the park policy establishment by setting up the priority of park development and valuation factor, valuation index as well as building a basic material to undeveloped neighborhood park in Daegu Metropolitan City. Thirteen urban neighborhood parks(1,841,663$m^2$) in the Daegu Metropolitan City were selected for this study. Analyzing and reviewing the previous research and literature review were conducted, and the evaluation index and analysis criteria were constructed to decide the development priority of parks. The results of this research are as follows; 1) Following to the result of the expert questionnaire test in order to estimate weight of valuation factors. It had a high score in available population, and estimated amount of the gross compensation, unpurchased land rate. On the other hand park rate of autonomous district, altitude, rate of population increase in autonomous district and a low score. 2) Generally, most f the plain type parks had a high score in the Sea level, land using pattern, an estimated amount of the gross compensation, but hill type parks had a high score the rate of green covered, park area for one person of administration building. 3) Daebong, Soosung, Dosan, 2.28 youth, Kyungnam parks were selected high priority. Soochang, Donsibong, Janggi, Dongin parks were selected middle priority. Bokhyun, Galsan, Manchon, Gusoosan parks, which were selected low priority. This research for undeveloped park is a basic research step to open up. Three many difficult things in shortage of the basic material for building valuation factor and measuring of the method measurement. The application of weight which make a decision importance among the valuation factor should have ore reasonable study and more scientific research from now because there still remains a lot of shortage of positive materials in there.