• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.4
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• pp.125-134
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• 2001

The purpose of this study is to provide basic information for a future countermeasure municipal and to establish several wastes policy after investigating solid wastes from Sunchon City. In addition, this research can be supported to manage of recycling plant and to reuse plant of each wastes. Results are as bellows after checking up and analysis type of waste in Sunchon city Unit solid waste generation rate from single family is $0.50kg/person{\cdot}day$, and total solid wastes are 41.9ton/day. Unit solid waste generation rate from apartments is $0.45kg/person{\cdot}day$, and solid wastes generation is 55.5ton/day. Unit solid waste generation rate from agricultural is $0.22kg/person{\cdot}day$ and total solid wastes are 13.5ton/day. That show total amount of municipal solid wastes from residential are 110.9ton/day. Unit solid waste generation rate from traditional markets is $1.85kg/person{\cdot}day$, and solid waste total volume is 5,400kg/day. Unit solid waste generation rate from small store is $2.03kg/person{\cdot}day$, and solid waste total are 25,101kg/day. Therefore, this show that total wastes are 30.50kg from downtown and commercial area. Solid waste quantity from Industrial area (Factory region) is 8.5ton and in case of school and hospitals are 7.2kg/day and 3.0kg/day. Solid waste amount from Institutional is 6.6kg/day. Food wastes were eliminated from municipal solid wastes as standard 63.4ton/day, and combustible wastes were 126.9ton/day. If it schedule about 5 years (by 2006) as durable year for food wastes treatment plant, it is expected 42.5ton/day for treatment capacity. We can judge that it is effective to be set 2 lines equipment ${\times}25ton/day$ as treatment ability under considering unexpected working condition such as any repair, trouble and an electrical load. If it schedule about 10 years (by 2011) as durable year for food wastes treatment plant, it is expected 150 ton/day for treatment capacity. We can conclude that it is effective to be set 2 lines equipment ${\times}80ton/day$ as treatment ability under considering working condition such as low loaded operating and the repair for incineration.

• Applied Chemistry for Engineering
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• v.22 no.2
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• pp.196-202
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• 2011

In this paper, a series of alkyl succinic acid esters for base oil were synthesized by condensation reaction of succinic anhydride and fatty alcohol. The structures of the synthesized esters were confirmed by $^1H-NMR$, FT-IR spectrum and GC analysis. Basic properties of esters such as kinematic viscosity (KV), refractive index (RI), total acid number (TAN) and pour points were measured and lubricating properties such as SRV wear scar diameter (SRV WSD), fraction coefficient (COF) and 4-ball wear (4-ball WSD) were also evaluated. As the results of basic properties, KV, RI and pour point of synthetic esters increased as the carbon chain of the esters increased. Measurement value of total acid number (TAN) was indicated between 0.2~4 mgKOH/g, and that metal working fluids and pressure working oils are acceptable to use as base oil. Also, lubricating properties of the esters showed as follows: 0.391~0.689 mm of SRV WSD, 0.110~0.138 of SRV COF and 0.49~0.55 mm of 4-ball WSD depended on the structure of the esters. In a comparison on the lubrication capacity of the SRV test based on polyester TMPTO, SRV WSD result showed that a better performance caused by the alkyl group. On the other hand, SRV COF test was not influenced of the alkyl group which the capacity of the lubricant was sightly diminished than the comparison material, regardless of the alkyl group.

• Journal of Korean Society of Forest Science
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• v.20 no.1
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• pp.1-44
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• 1973

Needless to say, the management of national forest in all countries is very important in view of the national mission and management purposes. Korean national forest is also in particular significant in promoting national economy for the continuous increasing of the demand for wood, conservation of the land and social welfare. But there's no denying the fact that the leading aim of the Korean forest policy has been based upon the conservation of forest resources and recovery of land conservation function instead of improvement of the forest productive capacity. Therefore, the management of national forest should be aimed as an industry in the chain of the Korean national economy. And the increment of the forest productive capacity based on rationalized forest management is also urgently needed. Not only the increment of the timber production but also the establishment of the good forest in quality and quantity are to bring naturally many functions of conservation and other public benefits. In 1908 Korean national forest was historically established for the first time as a result of the notification for ownership, and was divided into two kinds in 1911-1924, such as indisposable national forest for land conservation, forest management, scientific research and public welfare, and the other national forest to be disposed. Indisposable forest is mostly under the jurisdiction of national forest stations (Chungbu, Tongbu, Nambu), and the tother national forests are under custody of respective cities and provinces, and under custody of the other government authorities. As of the end of 1971, national forest land is 19.5% (1,297,708 ha) of the total forest land area, but growing stock is 50.1% ($35,406,079m^3$) of the total forest growing stock, and timber production of national forest is 23.6% ($205,959m^3$) of the year production of total timber in Korea. Accordingly, it is the important fact that national forest occupies the major part of Korean forestry. The author positively affirms that success or failure of the management of national forest controls rise or fall of forestry in Korea. All functions of forest are very important, but among others the function of timber production is most important especially in Korea, that unavoidably imports a large quantity of foreign wood every year (in 1971 import of foreign wood-$3,756,000m^3$, 160,995,000 dollars). So, Korea urgently needs the improvement of forest productive capacity in national forest. But it is difficult that wood production meets the rapid increase of demand for wood to the development of economy, because production term of forestry is long, so national forest management should be rationalized by the effective investment and development of forestry techniques in the long view. Although Korean national forest business has many difficulties in the budget, techniques and the lack of labour due to outflow of rural village labour by development of national economy, and the increase of labour wages and administrative expenses etc. the development of national forest depends on adoption of the suitable forest techniques and management adapted for social and economical development. In this view point the writer has investigated and analyzed the status of the management of national forest in Korea to examine the irrational problems and suggest an improvement plan. The national forestry statistics cited in this study is based on the basic statistics and the statistics of the forest business as of the end of 1971 published by Office of Forestry, Republic of Korea, and the other depended on the data presented by the national forest stations. The writer wants to propose as follows (seemed to be helpful in improvement of Korean national forest management). 1) In the organization of national forest management, more national forest stations should be established to manage intensively, and the staff of working plan officials should be strengthened because of the importance of working plan. 2) By increasing the staff of protection officials, forest area assigned for each protection official should be decreased to 1,000-2,000 ha. 3) The frequent personnel changes of supervisor of national forest station(the responsible person on-the-spot) obstructs to accomplish the consistent management plan. 4) In the working plan drafting for national forest, basic investigations should be carefully practiced with sufficient expenditure and staff not to draft unreal working plan. 5) The area of working-unit should be decreased to less than 2,000 ha on the average for intensive management and the principle of a working-unit in a forest station should be realized as soon as possible. 6) Reforestation on open land should be completed in a short time with a debt of the special fund(a long term loan), and the land on which growing hardwood stands should be changed with conifers to increase productivity per unit area, and at the same time techical utilization method of hardwood should be developed. 7) Expenses of reforestation should be saved by mechanization and use of chemicals for reforestation and tree nursery operation providing against the lack of labour in future. 8) In forest protection, forest fire damage is enormous in comparison with foreign countries, accordingly prevention system and equipment should be improved, and also the minimum necessary budget should be counted up for establishment and manintenance of fire-lines. 9) Manufacture production should be enlarged to systematize protection, processing and circulation of forest business, and, by doing this, mich benefit is naturally given for rural people. 10) Establishment and arrangement of forest road networks and erosion control work are indispensable for the future development of national forest itself and local development. Therefore, these works should be promoted by the responsibility of general accounting instead of special accounting. 11) Mechanization of forest works should be realized for exploiting hinterlands to meet the demand for timber increased and for solving lack of labour, consequently it should promote import of forest machines, home production, training for operaters and careful adminitration. 12) Situation of labour in future will grow worse. Therefore, the countermeasure to maintain forest labourers and pay attention to public welfare facilities and works should be considered. 13) Although the condition of income and expenditure grows worse because of economical change, the regular expenditure should be fixed. So part of the surplus fund, as of the end of 1971, should be established for the fund, and used for enlarging reforestation and forest road networks(preceding investment in national forest).

• Childhood Kidney Diseases
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• v.4 no.1
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• pp.69-76
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• 2000

Purpose: The Pathogenesis of primary noctllrnal enuresis(PNE) is still controversial. Genetic factor and maturational delay of micturition reflex including arousal disorder, lack of nocturnal Arginine Vasopressin(AVP) release and functional bladder capacity have been suggested. We analyzed the risk factors of PNE. Methods: Fifty five children with PNE (20 enuretics diagnosed at school physical examination of the first grade students at Mok-Dong Elementary School and 35 enuretics (Age 6-7 year) diagnosed at Ewha Womans University Mok Dong Hospital) and 221 control students without PNE at school physical examination were included. Genetic, stress and developmental factors, arousability, water intake, urine volume, maximun voiding volume and daytime voiding dysfunction were compared. Results: 1) There was no significant difference between PNE and control group in sex ratio, birth order, percentage of working mothers, parental and child personality, age to start walking, school record and duration of sleep. 2) Family history in the PNE group was significantly higher than control group ($20.0\%\;vs\;2.7\%$)(P<0.05). 3) The difficulty in arousal in the PNE group was significantly more common than the control group ($70.9\%\;vs\;54.3\%$)(P<0.05). 4) Nocturnal water intake in the PNE group was significantly greater than the control group ($330{\pm}158.2\;mL\;vs\;235{\pm}129.5\;mL$). Nocturnal urine volume in the PNE group was significantly greater than the control group ( $390{\pm}61.5\;mL\;vs\;140{\pm}43.2\;mL$)(P<0.05). Daily water intake and daily urine volume did not significantly differ between the two groups. 5) Maximum urine volume per void in the PNE group was significantly lower than the control group ($107{\pm}35.9\;mL\;vs\;236{\pm}41.3\;mL$). Daytime voiding dysfunction in the PNE group was significantly more common than the control group ($80.0\%\;vs\;57.9\%$). The voiding frequency in the PNE group was significantly greater than the control group ($7.0{\pm}3.6\;vs\;5.4{\pm}1.6$)(P<0.05). Conclusion: In addition to genetic factors and maturational delay of micturition reflex (difficulty in arousal, nocturnal polyuria and decreased functional bladder capacity) nocturnal polydypsia was found to be the important risk factors fur PNE. So nocturnal fluid restriction should be encouraged as the first-line management of PNE.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6C
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• pp.395-406
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• 2006

Drilled shafts are a common foundation solution for large concentrated loads. Such piles are generally constructed by drilling through softer soils into rock and the section of the shaft which is drilled through rock contributes most of the load bearing capacity. Drilled shafts derive their bearing capacity from both shaft and base resistance components. The length and diameter of the rock socket must be sufficient to carry the loads imposed on the pile safely without excessive settlements. The base resistance component can contribute significantly to the ultimate capacity of the pile. However, the shaft resistance is typically mobilized at considerably smaller pile movements than that of the base. In addition, the base response can be adversely affected by any debris that is left in the bottom of the socket. The reliability of base response therefore depends on the use of a construction and inspection technique which leaves the socket free of debris. This may be difficult and costly to achieve, particularly in deep sockets, which are often drilled under water or drilling slurry. As a consequence of these factors, shaft resistance generally dominates pile performance at working loads. The efforts to improve the prediction of drilled shaft performance are therefore primarily concerned with the complex mechanisms of shaft resistance development. The shaft resistance only is concerned in this study. The nature of the interface between the concrete pile shaft and the surrounding rock is critically important to the performance of the pile, and is heavily influenced by the construction practices. In this study, the influences of asperity characteristics such as the heights and angles, the strength characteristics and elastic constants of surrounding rock masses and the depth and length of rock socket, et. al. on the shaft resistance of drilled shafts are investigated from elasto-plastic analyses( FLAC). Through the parametric studies, among the parameters, the vertical stress on the top layer of socket, the height of asperity and cohesion and poison's ratio of rock masses are major influence factors on the unit peak shaft resistance.

• Journal of the Korean housing association
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• v.20 no.1
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• pp.59-70
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• 2009

The purpose of the study is to suggest the amount of space for each behavior according to the classification of behavior in the housing to plan the optimal floor space of the elderly housing. The method for calculating space for behavior begins with classifying behaviors, identifying them and then taking pictures of the model of elderly people who reproduce each behavior. Based on the pictures, body parts which are necessary for each behavior are assembled and the formula for behavioral space is created. The space for behavior is produced considering the body dimensions of Korean elderly in their sixty's as well as the furniture size and the psychological distance between people. 3D modeling is used to verify the result. Human behaviors can be classified into individual-related, housework-related, family-related, reception-related and other behaviors. These five behaviors are subdivided into more specific behaviors. The area for each specific behavior is calculated with the anthropometric data of the elderly, preferred furniture dimension and psychological area. As a result the required area for specific behaviors is as follows: the behavior of sleeping in a bed needs $4.3m^2$; the behavior of changing clothes on a chair, $1.7m^2$; the behavior of watching TV on the floor $1.3m^2$, the behavior of working and reading using a desk, $2.1m^2$, the behavior of exercise, $2.5m^2$; the behavior of showering on a chair, $1.3m^2$ and showering using a wheelchair, $1.9m^2$; the behavior of toileting using a wheelchair, $2.3m^2$; the behavior of washing up using a wheelchair, $1.9m^2$; the behavior of eating using a table for four persons, $4.4m^2$; the behavior of cooking and washing dishes, $0.9m^2$ per counter-top; the behavior of washing clothes using a washing machine, $0.9m^2$; the behavior of ironing on the floor $1.4m^2$; the behavior of reception(three persons) on the floor considering personal space, $4.0m^2$; the behavior of taking on and off shoes on a chair, $1.3m^2$. The result of the study is utilized as quantitative data to calculate optimal floor space for elderly housing. In addition, qualitative data such as characteristics of housing preference, spacial usage and storage capacity are necessary to produce the floor space which can provide convenient and safe living environment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.536-544
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• 2020

This study provides basic data for finding a plan for future teacher education in the future society by conducting an IPA-analysis of the abilities required for early-childhood who will become talented persons of the future society and the perceptions of early-childhood teachers about the era of the 4th-Industrial-Revolution. The study was conducted with 194 childhood teachers working in early-childhood educational institutions located in Jeju. It used a questionnaire of the demand survey for teacher education development for early-education based on the 4th-Industrial-Revolution. In the era of the 4th-Industrial-Revolution, the capabilities needed for early-childhood were revised and supplemented in 2016 at the World Economic Forum "Jobs Future Report". The frequencies and percentages were calculated to analyze the characteristics of each subject's background variables, the perceptions of early-childhood teachers and teacher education needs, and a t-test was conducted for each item to analyze the difference in importance and performance of early-childhood's competence. In the importance of competence required for infants who become talents for the future, the results showed that early-childhood teachers chose to have a high level of caring-sharing and curiosity-interesting ability. In the performance, they have a high level of caring-sharing and cooperation-communication ability.

• Journal of the Korean Geosynthetics Society
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• v.18 no.4
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• pp.273-286
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• 2019

A derelict bridge called WoljungGyo was restored in Gyeongju, the capital city of ancient Silla. WoljungGyo was originally built in 760AD, and later rebuilt in 1280AD during the Goryeo Kingdom. The bridge lasted in working condition for at least 520 years. The bridge was uncovered to the remains of both abutments and four piers, with only one or two steps remaining. One of the foundation for piers showed evidence of partial settlement. The cause of the partial settlement is important for the successful restoration of the bridge so that an extensive investigation was carried out, which includes layer stratification by boring, 2-D stiffness profiling by surface-wave tests, and large scaled-plate load test for evaluating capacity. In addition to the field studies in the Woljunggyo bridge, 3-D finite element analysis was also conducted. Based on the results of the site investigation and the numerical analysis, it was concluded that the further ground improvement to build the piers was not necessary so that the gravels were placed and leveled underneath the existing pier stones to compensate partial settlement before the restoration.

• Journal of Advanced Marine Engineering and Technology
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• v.41 no.1
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• pp.99-104
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• 2017

This study evaluated the heating performance of a hybrid heat pump system. The system was installed in a $100-m^2$ greenhouse to utilize surplus solar energy. A hybrid heat pump system was installed at Jocheon-ri, Jeju Island, for an empirical evaluation of the performance. The system consists of a heat storage tank and plate heat exchangers for several heat exchanges between the greenhouse and heat pump or storage tank. The system uses R410a as the working fluid and is controlled automatically by a defined set temperature of the greenhouse. This system incorporates two kinds of heat sources: outdoor air and a storage tank that collects heat from the topside of the greenhouse. The results showed that the heating capacity was 19.9 kW in the outdoor air source mode and 21.4 kW with direct heating from hot water in the thermal storage tank. These results are very similar to those of a previous study.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.3
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• pp.229-235
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• 2011

This research aims todevelopa compression/absorption hybrid heat pump system using an $NH_3/H_2O$ as working fluid.The heatpump cycle is based on a combination of compression and absorption cycles. The cycle consists of two-stage compressors, absorbers, a desorber, a desuperheater, solution heat exchangers, a solution pump, a rectifier, and a liquid/vapor separator. The compression/absorption hybrid heat pump was designed to produce hot water above $90^{\circ}C$ using high-temperature glide during a two-phase heat transfer. Distinct characteristics of the nonlinear temperature profile should be considered to maximize the performance of the absorber. In this study, the performance of the absorber was investigated depending on the capacity, shape, and arrangementof the plate heat exchangers with regard tothe concentration and distribution at the inlet of the absorber.