• Korean Journal of Environment and Ecology
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• v.36 no.5
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• pp.496-506
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• 2022

The growth of trees planted through transplantation rapidly decreases immediately after planting due to extreme disturbances such as root cutting and crown damage. Although the growth rate is recovered as time elapses, the time required to restore the original growth varies by species. Therefore, it is necessary to set an appropriate tree management period for survival after transplantation by analyzing each species' annual growth change. In this study, we analyzed the growth amount of deciduous broad-leaf species planted in the area where the riparian ecological belt was formed and proposed the management period based on the results. Slowed growth immediately after planting is a common phenomenon due to root cutting and pruning, the pre-works performed to increase tree survival rate during the transplantation process. Afterward, the original growth rate is recovered as time passes, but the time required may vary depending on the species and planting environment. Most of the trees showed a rapid decrease in growth immediately after transplantation. After that, although it is different for each species, most of them showed a gradual recovery from 2 years onwards. The analysis of the growth rate by tree species confirmed that it took 2 to 4 years, depending on the tree species, to recover the growth level before transplantation after a rapid decrease in growth immediately after transplantation. The results suggest that improving the defect rate of planted trees is necessary to meet the project objectives: ecological restoration and pollutant reduction. It requires setting a tree management period of at least two years and creating an appropriate base environment.

• Journal of Practical Agriculture & Fisheries Research
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• v.5 no.1
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• pp.64-76
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• 2003

This study was conducted in order to find out the basic data and informations for the accidents for repairing of agricultural machines. This study was summarized as fellows : 1. Among the total repair work, the ratio of repair accident was 68.9% and the accident ratio with power tiller, tractor, and combine was 84.8%. The accident occurred frequently in April to May and September to October because of frequent use of machines during this months. The accidents occurred often of ten to eleven and two to three afternoon in a day. 2. The 36.3% of the accident types was farming machines and the 60.4% of the accident occurred in yard of repair shop. The 34.4% of accident was caused by people, 26.2% by machines, 24.9% by environmental factors, and 14.5% by others. 3. In accident damage, human damage was 98.4% and economic damage was 43.6%. There was only 40.2% in having agricultural machinery insurance and 22.5% of research applicant answered that they would not have insurance in the future. 4. The 58.2% of the injured parts occurred in fingers, hands, wrists, or arms and the 74.4% of the damage types were bruise, prick or abrasion. The damaged parts of machinery were belt of power transmission device, chains, sharpened knives, narrow mechanism or cultivating knives for rotary. 5. The average days of medical treatment for casualty was 15.5 days and the average expense of medical treatment per person was 189,200 won. The days of temporary rest and the economic damage per person due to accident were 12.8 days and 469,300 won.

• Korea Trade Review
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• v.43 no.4
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• pp.155-175
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• 2018

This study estimates the technical efficiency and total factor productivity(TFP) of and analyzes the relationship between TFP and exports for Korean manufacturing companies from 2000 to 2016. Specially, TFP is decomposed into Technical Change(TC), Technical Efficiency Change (TEC), and Sale Effect(SE), and compared between large and small enterprises. First, in the case of technical efficiency, the Korean economy has been very vulnerable to external shocks, such as the sharp decline following the 2008 financial crisis. The efficiency of the electronics, automobile, and machinery sectors is low and needs to be improved. In addition, the technological efficiency of large enterprises is higher than that of SMEs in most manufacturing sub-sectors except for non-ferrous metals. In the case of TFP, most changes are due to TC, and the effective combination of labor, capital and the effect of scale have little effect, suggesting that improvement of internal structure is urgent. In addition, volatility due to the impact of the financial crisis in 2008 was much larger in SMEs than in large companies, so external economic impacts are more greater for SMEs than large enterprises. The relationship between TFP decomposition factors and exports shows that TC has a positive effect only on exports of SMEs. Therefore, in order to increase exports, in the case of SMEs, R&D support to promote technological development is needed. In the case of large companies, it is necessary to establish differentiated strategies for each export market, competitor company, and item to link efficiency and scale effect of exports.

• Journal of the Mineralogical Society of Korea
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• v.15 no.4
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• pp.329-344
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• 2002

Mineralogical and chemical characterization of some domestic bentonites, such as quantitative XRD analysis, chemical leaching experiments, pH and CEC determinations, were done without any separation procedures to understand their relationships among mineral composition, characteristics, and cation exchange properties. XRD quantification results based on Rietveld method reveal that the bentonites contain totally more than 25 wt% of impurities, such as zeolites, opal-CT, and feldspars, in addition to montmorillonite ranging 30～75 wt%. Cation exchange properties of the zeolitic bentonites are deeply affected by the content of zeolites identified as clinoptilolite-heulandite series. Clinoptilolite is common in the silicic bentonites with lighter color. and occurs closely in association with opal-CT. Ca is mostly the dominant exchangeable cation, but some zeolitic bentonites have K as a major exchangeable cation, The values of cation exchange capacity (CEC) determined by Methylene Blue method are comparatively low and have roughly a linear relationship with the montmorillonite content of the bentonite, though the correlated data tend to be rather dispersed. Compared to this, the CEC determined by Ammonium Acetate method, i.e.‘Total CEC’, has much higher values (50～115 meq/100 g). The differences between those CEC values are much greater in zeolitic bentonites, which obviously indicates the CEC increase affected by zeolite. Other impurities such as opal-CT and feldspars seem to affect insignificantly on the CEC of bentonites. When dispersed in distilled water, the pH of bentonites roughly tends to increase up to 9.3 with increasing the alkali abundance, especially Na, in exchangeable cation composition. However, some bentonites exhibit lower pH (5～6) so as to regard as ‘acid clay’. This may be due to the presence of $H^{＋}$ in part as an exchangeable cation in the layer site of montmorillonite. All the works of this study ultimately suggest that an assesment of domestic bentonites in grade and quality should be accomplished through the quantitative XRD analysis and the ‘Total CEC’measurement.

• Korean Journal of Community Nutrition
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• v.15 no.3
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• pp.308-328
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• 2010

As the older adult period $({\geq}65y)$ is increasing, it is needed to investigate the trend of aging-dependent anthropomeric index and nutrient intake, and establish the more specific dietary guide for the different stages of aging period. To find the difference in nutrient intake among the Koreans aged 50-64, 65-74 and 75 years and older, and also any characteristics of dwellers in longevity area, we recruited 1,083 subjects (385 male and 698 female) aged 50-95 years (mean age, 71.3 yrs) living in Kugoksoondam area (Kurye, Goksung, Soonchang and Damyang counties), known as a longevity-belt region in Jeonlaprovince, Korea. We measured some anthropometric index and collected 2 day-dietary record. Nutrient intakes were analyzed by using DW24 program. The mean height and weight of subjects aged 75 years and older were lower than Korean national reference. BMI and obesity $({\geq}25kg/m^2)$ prevalence were significantly decreasing with aging. Underweight $(BMI<18.5kg/m^2)$ prevalence was also increasing with aging, especially in males, and it was slightly higher than national average, but similar to that in some other rural area. Obesity prevalence of male subjects was lower compared to national prevalence, but abdominal obesity prevalence $(waist{\geq}80cm)$ was very high in females (about 89%). In both genders, the average proportional contribution of carbohydrate, protein and fat to energy intake was not different between 65-74 years and 75 years and older. On overall, nutrient intake and quality of diet of females were inferior to those of males so that many of females aged 75 years and older assumed to be at risk of malnourished status. Fiber, folate and vitamin E intakes were substantially higher compared to those in 2007 KNHNES and other some studies in rural area. While almost nutrient %EAR was significantly decreased with aging in females, there was no significant difference in %EAR for protein, vitamin A, $B_1$, $B_6$, $B_{12}$, niacin, Ca and Zn between 65-74 years and 75 years and older in males. Vitamin $B_2$ for male aged 50-64 years, vitamin $B_2$ and Ca for male aged 65 years and over and female aged 50-74 years, and vitamin $B_2$, vitamin C, Ca and folate intake for female aged 75 years and older were assessed to be at risk to undernutrition based on the prevalence of intake below EAR. MAR of 13 nutrients and the number of nutrients consuming below EAR were significantly decreasing with aging in both genders, however, the number of nutrients of INQ < 1 and the average mini-nutritional assessment score were not significantly different between 65-74 years and 75 years and older. Taken together, decreasing tendency of nutrients intake and the quality of diet with aging was more evident in females than in males, and it is unique that our subjects consumed substantially higher fiber, folate and vitamin E compared to not only urban but also some other rural areas.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.56-63
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• 2018

The management of Combined Sewer Overflows(CSOs) and Separated Sewer Overflows(SSOs) discharge directly to the effluent system in an untreated state, which occurs when the facility capacity is exceeded due to heavy rain, has become an important issue in recent years as the heavy rain becomes a regular phenomenon. Despite the continuous development of filtration technology, targeting densely populated urban areas, CSOs are rarely applied. Therefore, this study was carried out to optimize the process to apply CSOs in a pilot-scale horizontal flow filtration system with a rope-type synthetic fiber. The research was carried out in two steps: a preliminary study using artificial samples and a field study using sewage. In the preliminary study using an artificial sample, head loss of the filter media itself was analyzed to be approximately 1.1cm, and the head loss was increased by approximately 0.1cm as the linear velocity was increased by 10m/hr. In addition, the SS removal efficiency was stable at 81.4%, the filtration duration was maintained for more than 6 hours, and the average recovery rate of 98% was obtained by air backwashing only. In the on-site evaluation using sewage, the filtration duration was approximately 2 hours and the average removal efficiency of 83.9% was obtained when belt screen (over 450 mesh) was applied as a pre-treatment process to prevent the premature clogging of filter media. To apply the filtration process to CSOs and SSOs, it was concluded that the combination with the pre-treatment process was important to reinforce the hydraulic dimension for the stable maintain of operation period, rather than efficiency. Compared to the dry season, the quality of incoming sewage was lower in the rainy season, which was attributed to the characteristics of the drainage area with higher sanitary sewerage. In addition, the difference in removal efficiency according to the influent quality of the wet season and dry season was small.

• The Journal of Korean Society for Radiation Therapy
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• v.23 no.1
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• pp.13-19
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• 2011

Purpose: It's essential to minimize the tumor motion and identify the exact location of the lesions to achieve the improvement in radiation therapy efficiency during SBRT. In this study, we made the established compression belt to reduce respiratory motion and evaluated the usefulness of clinical application in SBRT. Materials and Methods: We analyzed the merits and demerits of the established compression belt to reduce the respiratory motion and improved the reproducibility and precision in use. To evaluate the usefulness of improved compression belt for respiratory motion reduction in SBRT, firstly, we reviewed the spiral CT images acquired in inspiration and expiration states of 8 lung cancer cases, respectively, and analyzed the three dimensional tumor motion related to respiration. To evaluate isodose distribution, secondly, we also made the special phantom using EBT2 film (Gafchronic, ISP, USA) and we prepared the robot (Cartesian Robot-2 Axis, FARARCM4H, Samsung Mechatronics, Korea) to reproduce three dimensional tumor motion. And analysis was made for isodose curves and two dimensional isodose profiles with reproducibility of respiratory motion on the basis of CT images. Results: A respiratory motion reduction compression belt (Velcro type) that has convenient use and good reproducibility was developed. The moving differences of three dimensional tumor motion of lung cancer cases analyzed by CT images were mean 3.2 mm, 4.3 mm and 13 mm each in LR, AP and CC directions. The result of characteristic change in dose distribution using the phantom and rectangular coordinates robot showed that the distortion of isodose has great differences, mean length was 4.2 mm; the differences were 8.0% and 16.8% each for cranio-caudal and 8.1% and 10.9% each for left-right directions in underdose below the prescribed dose. Conclusion: In this study, we could develop the convenient and efficient compression belt that can make the organs' motion minimize. With this compression belt, we confirmed that underdose due to respiration can be coped with when CTV-PTV margins of mean 6 mm would be used. And we conclude that the respiratory motion reduction compression belt we developed can be used for clinical effective aids along with the gating system.

• Journal of the Mineralogical Society of Korea
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• v.32 no.4
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• pp.235-247
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• 2019

The Central South Sea Mud (CSSM), developed in the Seomjin River estuary, is known to be supplied with sediments from Heuksan Mud Belt (HMB) and Seomjin River. However, in order to form a mud belt, more sediments must be supplied than supplied in the above areas. Therefore, research on additional sources should be conducted. In this study, clay minerals, major elements analyzes were performed on cores 16PCT-GC01 and 16PCT-GC03 in order to investigate the transition in the provenance and transport pathway of sediments in CSSM. The Huanghe sediments are characterized by higher smectite and the Changjiang sediments are characterized by higher illite. Korean river sediments contain more kaolinite and chlorite than those of chinese rivers. Korean river sediments have higher Al, Fe, K concentraion than Chinese river sediments and Chinese rivers have higher Ca, Mg, Na than those of Korean rivers. Therefore, clay minerals and major elements can be a useful indicator for provenance. Based on our results, CSSM can be divided into three sediment units. Unit 3, which corresponds to the lowstand stage, is interpreted that sediments from Huanghe were supplied to the study area by coastal or tidal currents. Unit 2, which corresponds to the transgressive stage, is interpreted to have a weaker Huanghe effect and a stronger Changjiang and Korean rivers effect. Unit 1, which corresponds to the highstand stage when the sea level is the same as present and current circulation system is formed, is interpreted that sediments from Changjiang and Korean rivers are supplied to the research area through the current.

• Journal of the Korea Society of Computer and Information
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• v.24 no.12
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• pp.51-57
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• 2019

In this paper, we analyzed the performance of IoT based smart wearable mine detection device. There are various mine detection methods currently used by the military. Still, in the general field, mine detection is performed by visual detection, probe detection, detector detection, and other detection methods. The detection method by the detector is using a GPR sensor on the detector, which is possible to detect metals, but it is difficult to identify non-metals. It is hard to distinguish whether the area where the detection was performed or not. Also, there is a problem that a lot of human resources and time are wasted, and if the user does not move the sensor at a constant speed or moves too fast, it is difficult to detect landmines accurately. Therefore, we studied the smart wearable mine detection device composed of human body antenna, main microprocessor, smart glasses, body-mounted LCD monitor, wireless data transmission, belt type power supply, black box camera, which is to improve the problem of the error of mine detection using unidirectional ultrasonic sensing signal. Based on the results of this study, we will conduct an experiment to confirm the possibility of detecting underground mines based on the Internet of Things (IoT). This paper consists of an introduction, experimental environment composition, simulation analysis, and conclusion. Introduction introduces the research contents such as mines, mine detectors, and research progress. It consists of large anti-personnel mine, M16A1 fragmented anti-mine, M15 and M19 antitank mines, plastic bottles similar to mines and aluminum cans. Simulation analysis is conducted by using MATLAB to analyze the mine detection device implementation performance, generating and transmitting IoT signals, and analyzing each received signal to verify the detection performance of landmines. Then we will measure the performance through the simulation of IoT-based mine detection algorithm so that we will prove the possibility of IoT-based detection landmine.

• The Journal of the Petrological Society of Korea
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• v.7 no.2
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• pp.77-97
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• 1998

We analyzed geochemical and radiogenic isotope data to investigate the genesis and source characteristics of the Onjeongri granite in the northern part of the Gyeongsang Basin. Field observation and K-Ar ages confirm late Cretaceous intrusion (ca. 87 Ma) of the Onjeongri granite. The hornblende geobarometery gives less than 2 kbar for the emplacement pressure of the Onjeongri granite. Geochemical and isotopic compositions suggest that the Onjeongri granite was formed in a relatively immature arc system. $SiO_2$ contents show a negative linear relationship with initial $^{87}Sr/^{86}Sr$ ratios, and an apparent positive correlation with $^{207}Pb/^{204}Pb$ ratios, suggesting an incomplete mixing or assimilation. However, the isotopic data known for any exposed rocks of the study area do not fit as an endmember, implying that the contaminant might reside in the lower crust. A review of published isotopic ages, geochemical, and Sr and Nd isotopic data for the Cretaceous to Tertiary granites in the Gyeongsang Basin indicates the followings. 1) Granitic magmatism in the Gyeongsang Basin were episodic. 2) Granitic rocks in the basin were derived from young (< 0.9 Ga) lower crust, and their isotopic signatures reflect heterogeneous source region. Geochemical and isotopic signatures of granitic rocks in the basin are difficult to explain by upper crustal contamination. 3) Granites in the Gyeongsang Basin have closely related to those in the San in Belt of the Inner Zone of Southwest Japan in terms of age, petrography, and isotopic and geochemical composition. 4) Sr-Nd isotopic signatures of the Onjeongri granite are relatively primitive compared with granitic rocks in the other parts of the Gyeongsang Basin and in the Inner Zone of Southwest Japan.