• Journal of Biosystems Engineering
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• v.4 no.1
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• pp.48-57
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• 1979

In order to obtain a standard reference for designing an adequate power rice transplanter, the cutting forces depending upon variety of seedling, sowing density, seedling age and soil moisture content of mat-type seedling were measured by the rice transplanter installed with force measuring device of dynamic strain gage system in the laboratory. The result of this study are summarized as follows : 1. Cutting velocity and acceleration transplanting hoe obtained from jinematic analysis of planting mechanism was 1.32m/sec and 81.5m/$sec^2$ when planting crank-shaft rpm was 160. 2. Little difference between cutting forces on 30-days old seelings of japonica and Indica type was observed, as the cutting forces determined were 2.0kg per hill for Japonica type and 2.1kg per hill for Indica type. 3. Cutting forces determined on 40-days old seedlings were 2.5kg, 2.3kg, 3.1kg and 2.9kg per hill for Milyang No.15, Tongil, Akibare and Milyang No.23 compared to the other varieties. 4. The cutting force was not greatly affected by the sowing densities , only five percent of differences were observed epending upon the sowing densities. 5. Cutting forces were 2.7kg and 2.0kg per hill on 40-days old seedlings and 30-days old seedlings respectively. About 38 percent of more forces was required in cutting 40-days old seedling than in cutting 30-days old seedlings. 6. More cutting forces were required as soil moisture content of mat-type seedling was decreased. 7. Root length after cutting by the planting hoe and their relationships with soil moisture content on 30-days old seedlings, are as follows ; $y=4.147-11.384x+ 28.854x^2$ where , $y$=root length after cutting. (cm) , $x$=soil ture content of mat type seedlings.(%, d.b.) 8. Cutting forces were varied with the width of cuttings ; those on 40-days old mat type seedlings were 2.7kg and 2.2kg per hill when cutting with 14 mm and 10mm of width respectively, about 32 percent of more forces was required when cuting with 14mm of width compared to 10mm of width.

• IE interfaces
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• v.19 no.4
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• pp.316-323
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• 2006

In this study, based on Weibull proportional age reduction model and age replacement policy, we analyze economic life of cutting tool which allows re-grinding. Re-grinding task, usually for high-priced machining tools(e.g., broaching tool), is a kind of preventive maintenance activities to extend tool life at the completion of a lot production. The numerical results are also presented. Among the parameters of Weibull proportional age reduction model, the re-grinding effect parameter and Weibull shape parameter have a strong effect on economic tool life, and in the cost parameters, shortage cost is most sensitive. With further study on the parameter estimation of tool life process and cost function, this study can be expected to give more practical contribution to management of general machining tools.

• Journal of Korean Society of Forest Science
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• v.103 no.3
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• pp.408-421
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• 2014

This study was carried out to investigate flora and vegetation in cutting slope along a construction age sequence (2007, 2009, 2010, 2011, 2012) of forest roads in Yongchiri, Younghyunmyon, Sacheonshi, Geyongsangnamdo. Mean slopes of the cutting and banking slopes of forest roads constructed were ranged from $42^{\circ}$ to $54^{\circ}$. Soil texture in the cutting and banking sides of forest roads constructed in 2012 was loam, while sandy loam in the cutting and banking slopes of forest roads constructed between 2007 and 2011. Vegetation cover percentage was higher in the banking slopes (66%) than the cutting slopes (49%) of forest roads. Total flora were higher in the banking slopes (50 species) than the cutting slopes (46 species) of forest roads. Species diversity was generally higher in the banking slopes than in the cutting slopes in all forest roads. In addition, the species diversity index was the highest in the cutting slopes (1.4015) of forest roads constructed in 2011, while the highest in the banking slopes (1.5603) of forest roads constructed in 2012. The results indicate that evenness index in the cutting and banking slopes of recent construction roads was high compared with old construction roads because of the distribution of simple plant species.

• Archives of Plastic Surgery
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• v.47 no.3
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• pp.250-255
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• 2020

Background Rosenthal et al. classified female, habitual, non-suicidal wrist cutters as a group and introduced the concept of wrist-cutting syndrome. We investigated the characteristics of wrist-cutting patients at our institution in comparison with results reported previously. Methods We conducted a retrospective study involving 115 patients who had cut their wrists and been examined at the emergency department of a single hospital in Seoul, Korea, between March 2014 and August 2018. Results There were more women (73 patients; 63.5%) than men (42 patients; 36.5%), and the women (mean age, 34.42 years) were significantly younger than the men (mean age, 50.07 years). The patients who had cut their wrists repeatedly were mainly women (22 of 26 patients; 84.6%); however, men caused more severe damage than women. Substance use before a suicide attempt did not significantly increase the severity of wrist cutting. Our institution planned and implemented a suicide prevention intervention program to improve the continuity of outpatient care. The number of patients who continued psychiatric treatment increased significantly after program completion. Conclusions We confirmed that most patients were young women who were not suicidal in the true sense because their wounds were not severe. Our study showed a protective role of the barrier tendons (flexor carpi radialis, palmaris longus, flexor carpi ulnaris), and we suggest careful repair of the barrier tendons to protect neurovascular structures against subsequent cutting events. We found that it was possible to improve the continuity of patient counseling by managing patients through a psychiatric treatment program.

• Journal of Korean Society of Forest Science
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• v.109 no.4
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• pp.468-476
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• 2020

we developed a stand density management diagram for Quercus variabilis in order to predict the final cutting ages of coppice forests based on management objectives. The sample data were classified into two groups: 603 data points for analysis and 113 data points for verification. Using these data, a stand density management diagram was constructed and a goodness-of-fit test was performed. The explanatory power (R2) of the constituent models for the stand density management diagram was 0.732 for the equivalent height curve and 0.990 for the equivalent diameter curve. According to the analysis of the final cutting age rangeof the highest production, the final cutting ages for 900 buds remaining per hectare was 42-44 years, and that for the 1,800 buds remaining per hectare was 38-42 years. With the third-grade log set as the production target, the final cutting age range with site index 16 and 14 was 25-28 years and 29-33 years, respectively. The results of this study provide baseline data for establishing a management plan for Q. variabilis coppice stands.

• Journal of Environmental Science International
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• v.13 no.3
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• pp.181-187
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• 2004

In case an average accumulation of the investigated area is 200$m^{3}$/ha with cutting age of 80 years applied, annual workload will be 77ha and require 5 teams; each team consisting of 5 persons, enabling stabled supply of lumbers of 15,500$m^{3}$ every year. If one cutover is less than 2ha with cutting age of 80 years applied, it's possible to protect the peculiar ecology and secure stabled labor, workload and lumbering. It may become model forest out of tropical forest management which is controversial all over the world. Of course this presupposes construction of access roads.

• Proceedings of the Korea Contents Association Conference
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• 2008.05a
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• pp.717-721
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• 2008

Gems are using in jewelry, accessory and culture goods etc. in the contemporary jewelry and beads jewelry are made of natural and synthetic are generalize and popularize regardless of age gaining popularity. But in spite of enlarging the scale of gems for beads market, design of them rely on foreign cutting skills. Therefore, in this thesis, we developed usable cutting gems for beads wedding, culture goods and local souvenir as well as beads jewelry. we make growing more and more interested in gem design and contribute activation of gems and jewelry industry proposing various design gems for beads.

• Journal of Korean Society of Forest Science
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• v.76 no.4
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• pp.390-396
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• 1987

The model and its example were provided to predict wood production for a district forest planning. The method of Gentan probability is widely accepted for the prediction of wood production. The suggested model is different in the decision of cutting age distribution from that of Prof. Suzuki; the former can use either Weibull distribution or Gamma distribution, but the latter is possible only by Gamma distribution. This developed system can be used not only for establishing a district forest planning, but also for providing forest management information, such as periodic harvest volume, growing stock, labor requirement, and so forth.

• Korean Journal of Agricultural Science
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• v.4 no.2
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• pp.344-390
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• 1977

The purpose of this paper was to schedule optimum cutting strategy which could maximize the total yield under certain restrictions on periodic timber removals and harvest areas from an industrial forest, based on a linear programming technique. Sensitivity of the regulation model to variations in restrictions has also been analyzed to get information on the changes of total yield in the planning period. The regulation procedure has been made on the experimental forest of the Agricultural College of Seoul National University. The forest is composed of 219 cutting units, and characterized by younger age group which is very common in Korea. The planning period is devided into 10 cutting periods of five years each, and cutting is permissible only on the stands of age groups 5-9. It is also assumed in the study that the subsequent forests are established immediately after cutting existing forests, non-stocked forest lands are planted in first cutting period, and established forests are fully stocked until next harvest. All feasible cutting regimes have been defined to each unit depending on their age groups. Total yield (Vi, k) of each regime expected in the planning period has been projected using stand yield tables and forest inventory data, and the regime which gives highest Vi, k has been selected as a optimum cutting regime. After calculating periodic yields and cutting areas, and total yield from the optimum regimes selected without any restrictions, the upper and lower limits of periodic yields(Vj-max, Vj-min) and those of periodic cutting areas (Aj-max, Aj-min) have been decided. The optimum regimes under such restrictions have been selected by linear programming. The results of the study may be summarized as follows:- 1. The fluctuations of periodic harvest yields and areas under cutting regimes selected without restrictions were very great, because of irregular composition of age classes and growing stocks of existing stands. About 68.8 percent of total yield is expected in period 10, while none of yield in periods 6 and 7. 2. After inspection of the above solution, restricted optimum cutting regimes were obtained under the restrictions of Amin=150 ha, Amax=400ha, $Vmin=5,000m^3$ and $Vmax=50,000m^3$, using LP regulation model. As a result, about $50,000m^3$ of stable harvest yield per period and a relatively balanced age group distribution is expected from period 5. In this case, the loss in total yield was about 29 percent of that of unrestricted regimes. 3. Thinning schedule could be easily treated by the model presented in the study, and the thinnings made it possible to select optimum regimes which might be effective for smoothing the wood flows, not to speak of increasing total yield in the planning period. 4. It was known that the stronger the restrictions becomes in the optimum solution the earlier the period comes in which balanced harvest yields and age group distribution can be formed. There was also a tendency in this particular case that the periodic yields were strongly affected by constraints, and the fluctuations of harvest areas depended upon the amount of periodic yields. 5. Because the total yield was decreased at the increasing rate with imposing stronger restrictions, the Joss would be very great where strict sustained yield and normal age group distribution are required in the earlier periods. 6. Total yield under the same restrictions in a period was increased by lowering the felling age and extending the range of cutting age groups. Therefore, it seemed to be advantageous for producing maximum timber yield to adopt wider range of cutting age groups with the lower limit at which the smallest utilization size of timber could be produced. 7. The LP regulation model presented in the study seemed to be useful in the Korean situation from the following point of view: (1) The model can provide forest managers with the solution of where, when, and how much to cut in order to best fulfill the owners objective. (2) Planning is visualized as a continuous process where new strateges are automatically evolved as changes in the forest environment are recognized. (3) The cost (measured as decrease in total yield) of imposing restrictions can be easily evaluated. (4) Thinning schedule can be treated without difficulty. (5) The model can be applied to irregular forests. (6) Traditional regulation methods can be rainforced by the model.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.33 no.3
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• pp.59-66
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• 2022

Objectives: This study aimed to investigate the clinical characteristics of adolescents hospitalized through the emergency room for intentional self-harm or suicide attempts. Methods: This retrospective study used data from the Korean National Hospital Discharge In-depth Injury Survey conducted between 2006 and 2018 for individuals aged 10-24 years. The clinical characteristics of the patients were analyzed and compared across sex and age groups using the Rao-Scott chi-square tests and multiple logistic regression analysis for complex survey data. Results: The most common psychiatric diagnosis was mood disorder (22.0%), and more female patients were diagnosed with it than male patients (p=0.010). The 19-24 years age group was diagnosed with mood disorder the most compared to other younger groups (p=0.012). Male patients used lethal methods more than female patients (p=0.008), and the 19-24 years age group used more drug poisoning and cutting or piercing (p<0.001) for intentional self-harm or suicide attempts than younger groups. Conclusion: Adolescents hospitalized for intentional self-harm or suicide attempts showed significant differences in clinical characteristics across sex and age groups. These findings suggest that measures for preventing self-harm or suicide attempts need to be differentiated according to the sex and age of adolescents.