• Korean Journal of Soil Science and Fertilizer
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• v.12 no.4
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• pp.169-178
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• 1980

Ammonium nitrate explosion technique was applied to seek a convenient method for the establishment of orchard on the undulating to rolling land or hill side of Pogog clay loam soil (Fine Aquic Fragiudalfs : Planosols) having high bulk density and low permeability. Explosions were made by three ammonium nitrate explosives placed in the bottom of 90cm deep auger hole with every 2m interval (Explosion I) and 4m interval (Explosion II) respectively. The effect of the explosion on physical properties of the soil was investigated and compared with the effect induced by manual digging, excavation of $1m{\times}1m$ in diameter and depth (Manual digging I) and trenching of $1m{\times}1m{\times}25m$ in width, depth, and length (Manual digging II) respectively. The results investigated after 7 months from the treatments are summarized as follows : 1. The explosion or manual digging reduced bulk density and hardness, whereas the treatments increased porosity, hydraulic conductivity, and available moisture-holding capacity of the soil. 2. The explosion of 4 m interval improved physical properties of the soil to optimum level up to 70cm of the distance from the explosion core in the range of depth 0-60cm, while in the case of depth from 60 to 100cm the optimum level was achieved only within 50cm radius. 3. When exploded in 2 m interval, the effect in the 0-60cm depth was overlapped between two explosion cores. The effect in the depth between 60 and 100cm, however, was found to be independent of the explosion intervals. 4. The manual digging was only costly and laborious but effective only within the work-up zone. 5. For the soils having bulk density higher than $1.4g/cm^3$ after the treatments, the field capacity determined 72 hours after a heavy rain was lower than the laboratory estimate at the suction of 1/3 atm. 6. The top growth of apple tree for the first year revealed that the explosion seemed better treatment than the manual digging, even though the difference was insignificant.

• Journal of Korean Society of Disaster and Security
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• v.9 no.2
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• pp.63-75
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• 2016

For safe water supply, residual chlorine has to be maintained in tap-water above a certain level from drinking water treatment plants to the final tap-water end-point. However, according to the current literature, approximately 30-60% of residual chlorine is being lost during the whole water supply pathways. The losses of residual chlorine may have been attributed to the current tendency for water supply managers to reduce chlorine dosage in drinking water treatment plants, aqueous phase decomposition of residual chlorine in supply pipes, accelerated chlorine decomposition at a high temperature during summer, leakage or losses of residual chlorine from old water supply pipes, and disappearances of residual chlorine in water storage tanks. Because of these, it is difficult to rule out the possibility that residual chlorine concentrations become lower than a regulatory level. In addition, it is concerned that the regulatory satisfaction of residual chlorine in water storage tanks can not always be guaranteed by using the current design method in which only storage capacity and/or hydraulic retention time are simply used as design factors, without considering other physico-chemical processes involved in chlorine disappearances in water storage tank. To circumvent the limitations of the current design method, mathematical models for aqueous chlorine decomposition, sorption of chlorine into wall surface, and mass-transfer into air-phase via evaporation were selected from literature, and residual chlorine reduction behavior in water storage tanks was numerically simulated. The model simulation revealed that the major factors influencing residual chlorine disappearances in water storage tanks are the water quality (organic pollutant concentration) of tap-water entering into a storage tank, the hydraulic dispersion developed by inflow of tap-water into a water storage tank, and sorption capacity onto the wall of a water storage tank. The findings from his work provide useful information in developing novel design and technology for minimizing residual chlorine disappearances in water storage tanks.

• Journal of the Korean Electrochemical Society
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• v.15 no.3
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• pp.172-180
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• 2012

The $LiMn_2O_4$ cathodes for lithium ion battery were synthesized from various precursors of manganese oxides and manganese hydroxides. As the first step, nanosized precursors such as ${\alpha}-MnO_2$ (nano-sticks), ${\beta}-MnO_2$ (nano-rods), $Mn_3O_4$ (nano-octahedra), amorphous $MnO_2$(nano-spheres), and $Mn(OH)_2$ (nano-plates) were prepared by a hydrothermal or a precipitation method. Spinel $LiMn_2O_4$ with various sizes and shapes were finally synthesized by a solid-state reaction method from the manganese precursors and LiOH. Nano-sized (500 nm) octahedron $LiMn_2O_4$ showed high capacities of 107 mAh $g^{-1}$ and 99 mAh $g^{-1}$ at 1 C- and 50 C-rate, respectively. Three dimensional octahedral crystallites exhibit superior electrochemical characteristics to the other one-dimensional and two-dimensional shaped $LiMn_2O_4$ nanoparticles. After 500 consecutive charge discharge battery cycles at 10 C-rate with the nano-octahedron $LiMn_2O_4$ cathode, the capacity retention of 95% was observed, which is far better than any other morphologies studied in this work.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.6
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• pp.24-36
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• 2019

This study shows that the role of residents in landscape management is becoming increasingly important. The purpose of this study is to suggest elements that can continue the operation of landscape agreements and directions for promoting them. Therefore, 1)the operational elements considering the sustainability of the landscape agreements were proposed by way of literature research, expert interviews, and surveys. 2)The sustainable operation of elements of the landscape agreement were applied and best practices were developed through interviews with participants and literature analysis. 3)The final plan operational elements considering the sustainability of the landscape agreements and the directions for implementation were presented. As for the results, it was first presented that the elements of continuous operation of the landscape agreement, consisted of 3 major categories, 10 subcategories, and 25 details. These include resident awareness, practical applicability, effectiveness of administrative means, securing the budget, maintenance, public relations, expert support, dedicated support organization, sustainability of participation, and resident participation and communication methods. It is a detailed list of items that should be considered in the preparation phase, maintenance phase, and conclusion phase. Second, it suggested the direction for the sustainable operation of the landscape agreements be highly backed by the residents, and after reaching consensus on a landscape agreement, it is necessary that the agreement is based on contents that the residents can execute themselves. In addition, it was found that there is a need for a system to prepare the basis for securing the budget for the continuity of work, preparation of the landscape agreements, and consultation and activity costs during the maintenance phase. In addition, continuous exchanges and capacity building among residents have signed landscape agreements, and step-by-step support from experts in accordance with the level of involvement of residents is necessary. Third, even if a landscape agreement is concluded in connection with public projects, it is understood that the residents have the capacity to participate and can continue to support the administration and experts to enable the continued operation of the landscape agreement.

• Tuberculosis and Respiratory Diseases
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• v.49 no.4
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• pp.466-473
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• 2000

Background : Patients with locally advanced non-small cell lung cancer are often treated with radiation alone or in combination with chemotherapy. Both modalities have a potentially damaging effect on pulmonary function. In order to examine changes in the cardiopulmonary exercise function of patients with locally advanced non-small cell lung cancer before and after conventional radiotherapy, we conducted a prospective study involving patients with such cancer, that had received radiation therapy. Method : Resting pulmonary function test, thoracic radiographic finding and cardiopulmonary exercise test(CPET) were assessed prior to and 4 weeks following radiation therapy in 11 male patients with locally advanced non-small cell lung cancer. Patient with endobronchial mass were excluded. Results : The forces vital capacity (FVC), forced expiratory volume in 1 second ($FEV_1$ and maximal voluntary ventilation (MVV) did not decreased between before and 4 weeks after radiation but the diffusing capacity (DLCO) had decreased by 11% 4 weeks after radiation, which was not statistically significant. No changes in maximal oxygen consumption ($VO_2$max), carbon dioxide production ($VCO_2$), exercise time and work load were attributed to radiation therapy. Follow up cardiopulmonary exercise testing revealed unchanged cardiovascular function, ventilatory function and gas exchange. No difference in cardiopulmonary exercise test performance was observed between pre- and post-radiation. Conclusion : Cardiopulmonary exercise function did not decrease within the short-term after the radiation of patients with locally advanced non-small cell lung cancer.

• Journal of the Korean GEO-environmental Society
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• v.20 no.6
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• pp.5-13
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• 2019

The international trend in soil nailed wall design has been evolved from the allowable stress design to limit state design and it is still currently ongoing. The design guidelines in Korea and Hong Kong still adopts the allowable stress design philosophy while those in others mostly do the limit state design. In this study, four soil nail design methods presented in the major design guidelines (U.S. FHWA GEC 7 (2015), Clouterre in France (1991), Soil nailing - best practice guidance in U.K. (CIRIA, 2005), Geoguide 7 in Hong Kong (2008) and Design standard for slope reinforcement work in Korea (KDS 11 70 15 f: 2016)) are described and analyzed in brief. The factor of safety and CDR (Capacity-to-Demand Ratio) which is used to measure the degree of conservatism of a design guide are obtained for the two cases. One is the design example presented in CIRIA (2005) and the other is in-situ loading test performed on the top of backfill of the soil nail wall to investigate the conservatism of design guidelines. It is revealed that the design method in overall stability of soil nail walls in domestic design method (CDR=0.78) is the most conservative and those by Clouterre (CDR=0.99, 1.09), Geoguide 7 (CDR=1.13, 0.97), U.S. FHWA (CDR=1.09, 1.07) and CIRIA (CDR=1.40, 1.16) in order from the second most conservative to the least conservative for the design example presented in CIRIA. For the in-situ loading test performed on the top of backfill of the soil nail wall, the order of conservatism is identical except that the places of Geoguide 7 (CDR=0.66, 0.72) and FHWA (CDR=0.73, 0.72) are changed. However, the results obtained among U.S. FHWA (2015) and Clouterre (1991) and Geoguide 7 (2008) are not so different.

• Korean Chemical Engineering Research
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• v.60 no.4
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• pp.606-612
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• 2022

Relatively high indoor CO₂ concentration (>1,000 ppm) has a negative impact on human health. In this work, indoor CO₂ adsorbent was developed by impregnating KOH or K₂CO₃ on commercial activated carbon, named as KOH/AC and K₂CO₃/AC. Commercial activated carbon (AC) showed relatively high BET surface area (929 m²/g) whereas KOH/AC and K₂CO₃/AC presented lower BET surface area of 13.6 m²/g and 289 m²/g. Two experimental methods of TGA (2,000 ppmCO₂, weight basis) and chamber test (initial concentration: 2,000 ppmCO₂, CO₂ IR analyzer) were used to investigate the adsorption capacity. KOH/AC and K₂CO₃/AC exhibited similar adsorption capacities (145~150 mg_CO2/g), higher than K₂CO₃/Al+Si supports adsorbent (84.1 mg_CO2/g_sample). Similarly, chamber test also showed similar trend. Both KOH/AC and K₂CO₃/AC represented higher adsorption capacities (KOH/AC: 93.5 mg_CO2/g K₂CO₃/AC: 94.5 mg_CO2/g_sample) K₂CO₃/Al+Si supports. This is due to the KOH or K₂CO₃ impregnation increased alkaline active sites (chemical adsorption), which is beneficial for CO₂ adsorption. In addition, the regeneration test results showed both K-based adsorbents pose a good regeneration and reusability. Finally, the current study suggested that both KOH/AC and K₂CO₃/AC have a great potential to be used as CO₂ adsorbent for indoor CO₂ adsorption.

• Journal of the Korean Wood Science and Technology
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• v.15 no.3
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• pp.44-55
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• 1987

In order to study the effect of sawdustboard combined with plastic chips, 0.5mm($T_1$), 1mm($T_2$), 1.4mm($T_3$) thick nylon fiber. polypropylene rope fiber(RP), and 0.23mm thick moth-proof polypropylene net fiber(NP) were cut into 0.5, 1, 2cm long plastic chips. Thereafter, sawdustboard combined with plastic chips prepared as the above and plastic non-combined sawdustboard(control) were manufactured into 3 types of one-, two-, and three layer with 5 or 10% combination level. By the discussions and results at this study, the significant conclusions of mechanical and physical properties were summarized as follows: 1. The MORs were shown in the order of 3 layer> 2 layer> 1 layer among plastic non-combined boards, and $T_3$ < $T_2$ < $T_1$ < RP (NP(5%) < NP(l0%) among plastic combined boards. In 2cm long plastic chip in 1 layer board, the highest strength through all the composition was recognized. 1 layer board showing the lower strength with 0.5cm plastic chip rendered to the bending strength improvement by 2 or 3 layer board composition. On the other hand, 2 or 3 layer combined with 1, 2cm long polypropylene net fiber chips incurred MOR's conspicuous decrease requiring optimum plastic chip combined level and consideration to combined type. 2. MOE in plastic non-combined 3 layer board exhibited sandwich construction effect by higher resin content application to surface layer in the order of 3layer>1layer>2layer with the highest stiffness of the board combined with polypropylene chip, while nylon chip-combined board had little difference from plastic non-combined board. In relevant to length and layer effect, 3 layer board combined with the 0.5cm long polypropylene net fiber chip in 5% and 10% combined level presented 34-43% and 44-76% stiffness increase against plastic non-combined board(control), respectively. Moreover, in 1 layer board, 30% stiffness increase with 10% against 5% combined level in the 1 and 2cm long polypropylene net fiber chip was obtained. 3. Stress at proportional limit(Spl) showing the fiber relationship (r: 0.81-0.97) between MOR presented in the order of 1 layer<2 layer<3 layer in plastic non-combined board. Correspondingly, combined effect by layer and plastic chip length was similar to MOR's. 4. Differently from previous properties(MOR, MOE, Spl). work to maximum load(Wml) of 2 layer board approached to that of 3 layer board. Conforming the above phenomenon. 2 layer combined with 0.5cm long polypropylene net fiber chip kept the greater work than 1 layer. The polypropylene combined board superior to nylon -and plastic non - combined board seemed to have greater anti - failing capacity. 5. Internal bond strength(IB), in contrast to MOR's tendency. showed in the order of T1

• Journal of Korean Academy of Nursing
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• v.7 no.2
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• pp.60-82
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• 1977

The purpose of this study is first, to analyse the present nursing education and the curriculum in Korea in view of the changes and the new tendency of nursing education and second, to compare our curriculum with that of America, where nursing activities are actively earring on and, third, to try to find out what we should reconsider and improve in our nursing education. The object of this study is the educational program and the curriculum from 1973 to 1976 by selecting each five from colleges and department of nursing in Korea and America. The results of the study were as fellows : . 1. The aim of nursing education puts impassion the role of leader, knowledge and technology of nursing, welfare of society and service of community in both the America and Korea. In Korea nursing is mainly restricted to the treatment of diseases, while in the America the items of the aim of nursing are mainly extended to the capacity for Self- realization of nurse, in Korea they are restricted to the treatment of diseases. 2. In Korea the rate of credit of the curriculum of nursing education is the highest in professional education, next in general education, next in supporting science and educational subject, while in America the rate of the credit is the highest in general education, next professional education and then supporting Science and educational subject isn′t included in the curriculum. 3. In both Korea and America the role of the animal credit allotment in general education, is the highest in the first year and the rate in supporting science is the highest in the second year. In Korea professional subjects are concentrated in the third year while in America there is a tendency that they are increasing in number in the grade order. 4. There is a tendency that the rate of the credit allotment of the main professional subjects in curriculum is higher in Korea than in America : that is, in Korea the rate of the allotment of the credit is the highest in medical - surgical nursing, next maternal - child nursing, next community - health nursing and the psychiatric nursing and there in a great difference in the rate of the allotment of each credit. While in America the rate of the allotment of the credit is the highest in community - health nursing, next in medical- surgical nursing, next in maternal - child nursing, and then in psychiatric nursing and there is little difference in the rate of tile allotment of each credit. 5. From general education, supporting science and professional education, they have considered the continuity and sequence in the structure of nursing curriculum of Korea and America. While in Korea we have partly made integration in tile content of the subjects. Most of the school in America, they have made integration in the content of subjects especially in all subjects, but in Korea we haven't made it in all subjects. 6. In the system and form of nursing education Problem solving method, Dialectical method and operational method are introduced in some America schools and in others there is a tendency that the whole nursing education has the system based on Preventive frame - work or Health -illness frame work ; while only one college has an attempt for Health - Illness continue in Korea. 7. In Korea nursing education, as the importance of health- nursing and team nursing, the aim which is also comparatively emphasized is about health management and service of collective community. The subject pertaining to the aim is the studies of community health nursing, which are more in number in America. 8. When we consider the association between the social, general aims ?f the nursing education and the formation of the curriculum in Korean nursing school the courses of study concerning "the role of leadership and cooperative personal relation": "nursing care for the group": dynamic nursing care": and "the system of the public health nursing associated with the understanding of the regional community" are insufficient as compared with those of America. Especially, the lack of the behavioral science including the nursing care connected with the care for the group, the basic science on the clinical and developmental psychology, anthropology in known to be a prominent issue.

• The Korean Journal of Air & Space Law and Policy
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• v.31 no.2
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• pp.37-72
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• 2016

In the aerospace field, besides special purpose airplanes, contracts for supply of various types of products such as prototypes, unmanned aerial vehicles and space launch vehicles are increasing. In the case of the contractor, it was planned to spend a large amount of money to supply the production, but if the purchase specification that presents the quality and performance standard of the product is poor or lacks the capacity to judge the performance, consuming enormous amounts of time and money. Even if the undertaker does not have the ability to supply the products with the required performance and quality to achieve the purpose of the contract, he/she must pay the cost of burial due to the incompleteness of the work and the compensation for the cancellation of the contract. In this case, the defendant ordered the plaintiff to supply the aircraft by the Happy Box method, which is capable of ILS Offset flight as specified in the Purchase Specification, but the plaintiff attempted to supply the aircraft by the RNAV method. Although the ILS ground signal can be inspected by the RNAV method, the aircraft manufactured in the manner claimed by the plaintiff does not have the ILS Offset flight function required by the purchase specification, so the defendant can not achieve the purpose required by the purchase specification. It was a question of whether a defendant's cancellation of contract was legitimate. The aircraft, which is the object of this contract, is a subordinate substitute, so the case contract is of undertaking. Therefore, in order to complete the work in this contract, the major structural parts of the aircraft must be manufactured as agreed and have the performance generally required in the social sense. However, the aircraft delivered by the plaintiff has serious defects because the defendant can not achieve the purpose required by the purchase specification due to the lack of the ILS Offset flight function required by the purchase specification. This deficiency is impossible for the plaintiff to repair, so the defendant 's cancellation of the contract is legitimate.