• Journal of Korean Society of Forest Science
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• v.83 no.4
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• pp.545-555
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• 1994

The objective of the study was to provide the useful scientific data on the early rehabilitation of the legging road after timber harvesting in the forest area. This study was carried out at logging roads which were constructed during 1989 and 1994 in Mt. Baekwoon. The field survey was conducted in July, 1991. Judging from the analysis of soil bulk density, time required for recovery as the undisturbed forest soil condition was more than 10 years in the road which was left, and the regression equation is as follows, $$Y_1=1.4195-0.0744{\cdot}X(R^2=0.91)$$ $$Y_2=1.4673-0.0688{\cdot}X(R^2=0.73)$$ (X : elapsed year after road construction. $Y_1$, $Y_2$ : soil bulk density($g/cm^3$) at 0~7.5cm, and 7.5~15.0cm, respectively) Especially soil bulk density with buffer strip-woods was $0.890-0.903g/cm^3$, so it was 20% lower than that of logging road surface without buffer strip-woods. Among the 7 factors, location, sand content, and soil hardness had statistically significant effect on the soil bulk density in logging road surface. The pioneer species on logging road surface were Rhus cratargifolius, Prunus chinensis, and Lespedeza cyrtobotrya, etc. in woody species, and Pteridium aquilinum, Arundinella hirta, and Lysimachia clethroides, etc. in herb species. So, in process of year, average plant coverage were 70% on cutting and banking slope and 20% on logging road surface which elapsed 6 years after logging road construction. Through this research, buffer strip-woods must be remained for environmental conservation of forest conditions, and from the time to be closed the road, planting, seeding, and grazing works could be effective to the soil condition and vegetation recovery.

• Economic and Environmental Geology
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• v.36 no.5
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• pp.321-328
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• 2003

The epithermal gold and base metal deposit of the Tanggeung district of West Java consists of four major veins(Celak, Cigodobras, Cilangkap and Pasirbedil) with NS to N10$^{\circ}$∼20$^{\circ}$E and N75$^{\circ}$W strikes. The veins occur within fractures cutting the crystal and lithic tuff of Jampang Formation(Oligo-Miocene) in and around the Mt. Subang of the western Java, Indonesia. The ore mineralization is characterized by the occurrence of pyrite, sphalerite, galena, chalcopyrite, and small amounts of bornite and Fe-oxides. Hydrothermal alteration, associated with the mineralization, was dominantly silicified and enveloped by the phyllitic(sericitic), argillic and propylitic alteration containing the disseminated pyrite. Gangue minerals consist of interstratified smectite-illite, chlorite, sericite, and minor kaolinite. The presence of vapor-rich fluid inclusions in quartz veins suggests that boiling occurred locally throughout ore deposition. Fluid inclusion studies suggest that the ore fluid evolved from initial high temperatures(〓34$0^{\circ}C$) to later lower temperatures(〓19$0^{\circ}C$). Salinities range from 0.0 to 8.3 wt percent NaCl equiv. The relatively high increase in salinity(up to 8.3 wt percent NaCl equiv) might be explained by a local boiling and by a participation of magmatic fluids, supported by the sulfur isotope results. Evidence of fluid boiling suggests that the pressure decreased from 200 bars to 120 bars. This corresponds to the depths of approximately 750 to 1,200 m in a hydrothermal system that changed from lithostatic to hydrostatic conditions. Using homogenization temperatures and paragenetic constraints, the calculated $\delta$$^{34}$ S values of $H_2S$ in ore fluid are -0.2 to 1.8 permil close to the 0 permil isotopic value of magmatic sulfur.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.1
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• pp.11-20
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• 2004

This pot experiment was conducted to investigate the effects of combined micronutrient application($T_1$;control, $T_2$; Fe, $T_3$; Fe＋Mn, $T_4$: Fe＋Mn＋Cu, $T_5$ ; Fe＋Mn＋Cu＋Zn, $T_6$ ; Fe＋Mn＋Cu＋Zn＋Mo, $T_7$ ;Fe＋Mn＋Cu＋Zn＋Mo＋B) on forage performance of pure and mixed cultures of orchardgrass and white clover. This 4th part was related to the changes in the contents of micronutrients(Fe, Mn, Cu, Zn, Mo, and B) in forages. The results obtained are summarized as follows: 1. General differences have been showed in the contents of micronutrients based on the treatments, forage species, pure/mixed culture, cutting order, and additional fertilization, especially N. Compared to pure culture, orchardgrass showed relatively high contents of Mn and Zn, and low contents of B and Fe in mixed culture. White clover, however, tended to be exactly opposed to the above trends. The contents of Cu and Mo did not show any differences between pure and mixed cultures. 2. In relative comparison, the $T_7$ influenced negatively on the contents of Cu, Zn, and Mo in orchardgrass. The $T_7$ also influenced negatively on the contents of Mo in white clover. However, the $T_7$ influenced positively on the contents of Mn in orchardgrass, and also influenced positively on the contents of Fe, Mn, and Cu in white clover. Because of the antagonism between Fe and Mn, the Fe contents in both forages were significantly decreased by the $T_3$. Under the various conditions, the differences among Fe contents tended to be more significant in white clover than in orchardgrass. 3. At the $T_6$ and $T_7$, the Mo contents in both forages tended to be relatively high. The Mo contents, however, were somewhat decreased by the $T_7$ 7/. The Mo-toxicity, which was caused by the high Mo-contents, tended to be diminished, and was likely to be prevented by the optimum B/Mo ratio and B application($T_7$ ).

• KEPCO Journal on Electric Power and Energy
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• v.6 no.3
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• pp.305-313
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• 2020

The use of cable tunnels for electric power transmission as well as their construction in difficult conditions such as in subsea terrains and large overburden areas has increased. So, in order to efficiently operate the small diameter shield TBM (Tunnel Boring Machine), the estimation of advance rate and development of a design model is necessary. However, due to limited scope of survey and face mapping, it is very difficult to match the rock mass characteristics and TBM operational data in order to achieve their mutual relationships and to develop an advance rate model. Also, the working mechanism of previously utilized linear cutting machine is slightly different than the real excavation mechanism owing to the penetration of a number of disc cutters taking place at the same time in the rock mass in conjunction with rotation of the cutterhead. So, in order to suggest the advance rate and machine design models for small diameter TBMs, an EPB (Earth Pressure Balance) shield TBM having 3.54 m diameter cutterhead was manufactured and 19 cases of full-scale tunneling tests were performed each in 87.5 ㎥ volume of artificial rock mass. The relationships between advance rate and machine data were effectively analyzed by performing the tests in homogeneous rock mass with 70 MPa uniaxial compressive strength according to the TBM operational parameters such as thrust force and RPM of cutterhead. The utilization of the recorded penetration depth and torque values in the development of models is more accurate and realistic since they were derived through real excavation mechanism. The relationships between normal force on single disc cutter and penetration depth as well as between normal force and rolling force were suggested in this study. The prediction of advance rate and design of TBM can be performed in rock mass having 70 MPa strength using these relationships. An effort was made to improve the application of the developed model by applying the FPI (Field Penetration Index) concept which can overcome the limitation of 100% RQD (Rock Quality Designation) in artificial rock mass.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.35 no.1
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• pp.10-24
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• 2017

The research takes note of the formation process and settling period of Gwandong-Palkyung(關東八景, Eight Sites of Eastern Korea), the representative palgyeong(prominent eight sites) and jipgyeong(集景, landscape collection of scenic beauty), and investigates the time of formation regarding the palkyung and jipgeyong of Gwandong's scenic beauty through the analysis and interpretation of bibliographic data, and reference data. The result of the study is as follows. As the first document that records the terminology of "Gwandong-Palkyung" is "Daphongeunggil(答洪應吉)" of Yi, Hwang(李滉), Gwandong-Palkyung is inferred to be settled within the recognition of the people even before the 16th century. The geographic analysis result including "Sinjeung Donggukyeojiseungram(新增東國輿地勝覽)", Gwandong-Palkyung expanded as Gwandong-Sipkyung in early to middle of the 16th century. The first confirmed landscape collection regarding Gwandong-Palkyung in this study is confirmed in Shin Zup(申楫)'s "Yeonggwandong-Palkyung(詠關東八景)", thus, the terminology of Gwandong-Palkyung existed before 16th century at the latest. The settlement time of current "Palkyung" collection is estimated to be early 17th century at the latest. Poetries regarding Gwandong-Palkyung, and the frequency on the appearance of Gwandong scenic beauties are analyzed as making clear of the concentrated phenomenon on the sceneries of Gwandong-Palkyung. On the other hand, the collection of Gwandong-Palkyung in the domain of arts is confirmed initially in the ${\ll}$Gwandongpalkyungdobyeong(關東八景圖屛)${\gg}$ of Heo, Pil(許泌). Gwandong-Palkyung, expressed as the actual scene landscape painting shows similar tendencies of the conditions in the jipgyeong from the poetry, but the appearance rate of the painting subject was more prominent in visual solidarity and cohesion due to the reflection of the importance on icon(圖像) of the art works produced with particular meaning in the case of fixed ideal system. From late Joseon to modern times, ${\ll}$palpokbyeongpung(八幅屛風)${\gg}$ of various forms of folk painting is a corroborative evidence notifying that the cultural phenomenon of Gwandong-Palkyung has entered the universal period of embrace. Also, the 13 scenic beauties of Gangwon-Do appearing in the games of Namseungdo and Myeongseungyuramdo include Gwandong-Palkyung, which confirms the settlement of Gwandog-Palkyung even within the culture of games in late Joseon. Such results demonstrate the existence of awareness regarding Gwandong-Palkyung from the first half of the 15th century, which is presumed to have completely settled in the 17th century through the continuous development of formative process in the 16th century. Ultimately, Gwandong-Palkyung is the concrete formation of regional scenic beauties that individually gained its reputations as scenery from the Koryo Dynasty to late 17th century. Gwandong-Palkyung of the scenic beauty of Gwandong is a unique cultural scenery of the region that have germinated and formed through the process of cutting and polishing of long time to collect the best eight of scenic beauty from the many participation of sightseeing culture.

• Horticultural Science & Technology
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• v.33 no.1
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• pp.70-82
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• 2015

This study was conducted to establish an efficient screening system to identify melon resistant to Fusarium oxysporum f. sp. melonis. F. oyxsporum f. sp. melonis GR was isolated from infected melon plants collected at Goryeong and identified as F. oxysporum f. sp. melonis based on morphological characteristics, molecular analyses, and host-specificity tests on cucurbits including melon, oriental melon, cucumber, and watermelon. In addition, the GR isolate was determined as race 1 based on resistance responses of melon differentials to the fungus. To select optimized medium for mass production of inoculum of F. oxysporum f. sp. melonis GR, six media were tested. The fungus produced the most spores (microconidia) in V8-juice broth. Resistance degrees to the GR isolate of 22 commercial melon cultivars and 6 rootstocks for melon plants were investigated. All tested rootstocks showed no symptoms of Fusarium wilt. Among the tested melon cultivars, only three cultivars were susceptible and the other cultivars displayed moderate to high resistance to the GR isolate. For further study, six melon cultivars (Redqueen, Summercool, Superseji, Asiapapaya, Eolukpapaya, and Asiahwanggeum) showing different degrees of resistance to the fungus were selected. The development of Fusarium wilt on the cultivars was tested according to several conditions such as plant growth stage, root wounding, dipping period of roots in spore suspension, inoculum concentration, and incubation temperature to develop the disease. On the basis of the test results, we suggest that an efficient screening method for melon plants resistant to F. oxysporum f. sp. melonis is to remove soil from roots of seven-day-old melon seedlings, to dip the seedlings without cutting in s pore s uspension of $3{\times}10^5conidia/mL$ for 30 min, to transplant the inoculated seedlings to plastic pots with horticulture nursery media, and then to cultivate the plants in a growth room at 25 to $28^{\circ}C$ for about 3 weeks with 12-hour light per day.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.57 no.1
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• pp.57-68
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• 2021

In order to collect basic data for the improvement of fishing systems in coastal improved stow net fishery, a questionnaire survey and on-site hearing were conducted from May 10 to June 11, 2019 on the basic items of coastal improved stow net fishery and safety accidents that occurred during fishing operation. The questionnaire for the survey on the actual conditions of coastal improved stow net fishery consisted of a survey on basic matters (six questions) and a questionnaire (six questions) on safety accidents occurring during fishing operation. The results of the survey on basic items were analyzed by region (Incheon, Seocheon, Gunsan and Mokpo), by the captain's age (less than 50 years of age, 50 to 60 years and more than 60 years of age), by the captain's career (less than 20 years, 20 to 30 years, 30 to 40 years and more than 40 years) and by the age of fishing vessel (less than 10 years, 10 to 20 years and more than 20 years). According to the survey on basic items of coastal improved stow net fishery such as the captain's age, the captain's career, the age of fishing vessel, the fishing nets in use, the crews on board and the operation days per voyage by region, the average captain's age was 55.7 years, the average captain's career was 20.5 years, the average age of fishing vessels was 9.0 years, the average numbers of nets used by fishing boats was 14.0 sets, the average numbers of crew on board a fishing boat was 4.4 persons and the average numbers of operation days per voyage was 4.9 days (p < 0.05). As a result of the survey on safety factors during fishing operations, such as experience of ship accidents, major causes of ship accidents experienced, causes of ship accidents (first priority), experience of human accidents, major causes of human accidents, and causes of human accidents (first priority), more than 96% of the respondents experienced ship accidents including collisions with other vessels or fishing gear during fishing operations. The most significant cause of the accident was the other's fishing gear installed in the fishing grounds. The first possible causes of ship accidents during fishing operations were found to be other fishing gear installed in fishing grounds, steering or engine failure, and inability to avoid accidents during casting and hauling nets. The survey of the experience of human accidents, such as injuries or sea falls, showed that more than 90% of the respondents experienced human accidents during fishing operations. The most important cause of accidents experienced during fishing operations was stucked in a fishing gear during casting and hauling nets. The first important causes of accidents during fishing operations were movement of the fishing gear during casting and hauling nets, damage of the fishing gear such as rope cutting. The results are expected to be provided as a basic data to prevent safety accidents occurring during fishing operation and improve the fishing system in the coastal improved stow net fishery.

• Journal of Korean Society of Forest Science
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• v.111 no.4
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• pp.567-582
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• 2022

Chainsaw use for motor-manual timber harvesting in South Korea is associated with worker safety issues. However, forestry operations such as timber harvesting have already been mechanized to reduce hazards to workers and increase productivity. This study analyzed the productivities and costs of felling and processing, felling and processing using an excavator-based stroke harvester for Pinus rigida and Quercus mongolica stands. To efficiently operate the stroke harvester, we developed a regression equation to estimate the productivities of felling and processing, felling, and processing operations,and we conducted sensitivity analysis of the operation costs using DBH and machine utilization. The felling and processing productivity was 6.53 and 4.02 m³/SMH for P. rigida a nd Q. mongolica, respectively, and the cost was 17,983 and 29,210 won/m³, respectively. The felling productivity for P. rigida a nd Q. mongolica wa s 40.9 and 23.0 m³/SMH, respectively, and the cost was 2,667 and 4,743 won/m³, respectively. The processing productivity for P. rigida and Q. mongolica was 8.25 and 7.75 m³/SMH, respectively, and the cost was 15,296 and 16,283 won/m³, respectively. In the developed regression equation, the DBH, traveling distance, and number of cuttings were found to be important factors (p<0.05). Therefore, it is necessary to construct a DB considering the various conditions and species associated with harvester operations, and further research is needed to increase the accuracy of predicting operation productivity and costs.

• Journal of Practical Agriculture & Fisheries Research
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• v.16 no.1
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• pp.193-206
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• 2014

The objectives of the project are to increase farmers' income through GAP and to reduce the loss of agricultural produce, for which the Korean partner takes a role of transferring needed technologies to the project site. To accomplish the project plan, it is set to implement the project with six components: construction of buildings, installation of agricultural facilities, establishment of demonstration farms, dispatching experts, conducting training program in Korea and provision of equipments. The Project Management Committee and the Project Implementation Team are consisted of Korean experts and senior officials from Department of Agriculture, Myanmar that managed the project systematically to ensure the success of the project. The process of the project are; the ceremony of laying the foundation and commencing the construction of training center in April, 2012. The Ribbon Cutting Ceremony for the completion of GAP Training Center was successfully held under PMC (MOAI, GAPI/ARDC) arrangement in SAl, Naypyitaw on June 17, 2012. The Chairman of GAPI, Dr. Sang Mu Lee, Director General U Kyaw Win of DOA, officials and staff members from Korea and Myanmar, teachers and students from SAl attended the ceremony. The team carried out an inspection and fixing donors' plates on donated project machineries, agro-equipments, vehicles, computers and printer, furniture, tools and so forth. Demonstration farm for paddy rice, fruits and vegetables was laid out in April, 2012. Twenty nine Korean rice varieties and many Korean vegetable varieties were introduced into GAP Project farm to check the suitability of the varieties under Myanmar growing conditions. Paddy was cultivated three times in DAR and twice in SAl. In June 2012, vinyl houses were started to be constructed for raising seedlings and finished in December 2012. Fruit orchard for mango, longan and dragon fruit was established in June, 2012. Vegetables were grown until successful harvest and the harvested produce was used for panel testing and distribution in January 2013. Machineries for postharvest handling systems were imported in November 2012. Setting the washing line for vegetables were finished and the system as run for testing in June 2013. New water tanks, pine lines, pump house and electricity were set up in October 2013.