• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.3
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• pp.77-91
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• 2015

This study aims to suggest adequate soil management through the analysis of physicochemical properties of soil in the planting grounds of Incheon International Airport, which was constructed on a massive land reclamation site. Study areas were 5 sites at the international business complex, the passenger terminal, the airport support complex, the free trade zone, and the access road. Soil profile analysis showed that 9 plots out of the 27 plots were hardpan and heterospere within 80cm from the soil surface. The earth laid on the ground was categorized as gravel based soil(4 plots), dredged soil from the sea bottom and mixed reclamation materials(2 plots), clay with poor permeability(3 plots) and waste construction material(1 plot). Average soil hardness was $11.5kg/cm^2$ and soil textures were sandy soil, sandy loam and loamy sand. Average soil pH was 6.7 and average organic matter content was 0.7%. Electrical conductivity was 0.0dS/m and exchangeable cation concentrations were $Ca^{2+}$ 3.4cmol/kg, $Mg^{2+}$ 1.5cmol/kg, $K^+$ 0.3cmol/kg and $Na^+$ 1.0cmol/kg. Average cation exchange capacity was 11.0cmol/kg. Although average figures in Solum mostly meet the landscape design criteria, properties of each soil layer showed various values sometimes over the limit. Base saturations were $Ca^{2+}$ 29.9%, $Mg^{2+}$ 13.3% and $K^+$ 3.7% for lower soil, $Ca^{2+}$ 33.3%, $Mg^{2+}$ 17.0% and $K^+$ 2.7% for mid-soil and $Ca^{2+}$ 32.6%, $Mg^{2+}$ 12.2% and $K^+$ 1.9% for upper soil. Exchangeable sodium percentages were 16.4% for lower soil, 7.5% for mid-soil and 4.7% upper soil. Sodium adsorption rates were 0.8 for lower soil, 0.3 for mid-soil and 0.2 for upper soil. Factors affecting to the vegetation growth were heterogeneity and poorness of solum, disturbance of dredged soils, high soil hardness including hardpan in the subsurface soil layer and shallow effective soil depth, high soil acidity, imbalance of base contents, low organic matter content and low available phosphate levels in the soil.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.2
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• pp.119-128
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• 2013

Since the early 2000s, demand for coastal dredging projects have been significantly increased, and the dredged sediments have showed the continuing marked increases through the multiple projects with other coastal development and constructions. As significant or potential degradation of marine environment has been mounting, we checked the current situation of marine environmental impact assessment through marine water and sediment qualities in relation with dredging projects of the sea area utilization consultation statements submitted in 2011. While analysis percentages of the general items were usually higher, harmful components such as metals revealed wide variation of analysis percentages. In the event of analysis of metals, the pre-treatment process (full digestion) and analysis method were not properly implemented in accordance with the guidelines for preparation of consultation statements. Although not specified in the guidelines, verification procedures (tests of recovery efficiency and detection limit) to secure the reliability were almost ignored. As a result, most of developers did conduct poor marine environmental impact assessment on coastal dredging and related projects. We suggested that the responsible government authority should establish new detailed guidelines on the sea area utilization consultation for more strict evaluation and diagnosis of marine environment and distinctly request the developer to obey the guidelines by complementing the system of the sea area utilization consultation.

• Journal of Yeungnam Medical Science
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• v.14 no.2
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• pp.314-328
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• 1997

A cross-sectional study was performed to evaluate the effects of chronic exposure to low-dose solvent on neurobehavioral performance of 48 male workers exposed to organic solvents. A control group of 50 workers was selected from same factories. Each worker completed a medical and occupational questionnaire and four tests of Neurobehavioral Core Test Battery. These included Benton visual retention test, digit symbol, digit span, and pursuit aiming. Comparison of mean performance showed a significantly poorer performance on digit symbol, digit span, and pursuit aiming. In univariate analysis, age contributed to poor performance on Benton visual retention test and educational level was found to reduce the performance on symbol digit in both groups. Amount of alcohol intake was found to reduce the performance on digit symbol and smoking appeared to slow pursuit aiming in the exposure group. In multiple regression analysis, controlling for age, educational level, alcohol, and smoking, Solvent exposure was found to be associated with performance of digit span, and number of correct dot of pursuit aiming. Age on Benton visual retention, educational level on digit symbol, arid smoking on pursuit aiming were found to be a significant factors on each test items. This study suggest that short-term memory, and perception can be affected easily by chronic exposure of organic solvents which air concentration levels were under the Threshold Limit Value.

• Journal of Environmental Health Sciences
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• v.37 no.4
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• pp.267-278
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• 2011

Objectives: A great number of hazardous agents can be emitted from various types of art-creation in a fine arts college, but little data on exposure assessment has been published. A variety of processes encompassing toxic or non-toxic materials, tools, and components are involved in a sculptor work at a fine art college. The aim of this study was to assess exposure levels to particulates and noise during sculpture classes in a college of fine arts. Methods: Students in sculpture classes participated in this study. Mass, number, and surface area concentrations of particulates, noise level, temperature and relative humidity were monitored by both personal and area sampling during the tasks of metal, wood, and stone sculpting. Results: The number and surface concentration of particulates was the highest in the task of wood sculpting, followed by metal and stone work. The mass concentration of particulates was the highest in stone sculpting (personal GM 3.0 mg/$m^3$, GSD 3.0), followed by wood (personal GM 1.5 mg/$m^3$, GSD 1.8) and metal work (personal GM 0.95 mg/$m^3$, GSD 1.51) in that order. Occupational exposure limits (OEL) for particulates depends on the type of particulate. For wood dust, 86% (six subjects) of the personal samples and all area samples exceeded the Korean OEL for wood dust (1 mg/$m^3$), while 20% (two subjects) among stone sculpting students were exposed above the Korean OEL (10 mg/$m^3$). In contrast, metal sculpting did not exceed the OEL (5 mg/$m^3$). For noise level, metal sculpting students (Leq 95.1 dB(A) in the morning, 85.3 dB(A) in the afternoon) were exposed the most, followed by stone sculpting (88.3 dB(A)), and wood sculpting (84.8 dB(A)) in that order. Compared with the 90 dB(A) of the Korean OEL and 85 dB(A) of the American Conference of Governmental Industrial Hygienists' threshold limit value (ACGIH-TLV) for noise, 100% of the subjects (five subjects) and area samples during metal sculpting in the morning session exceeded both OELs, but only three subjects (60%) exceeded the ACGIH-TLV in the afternoon session. For stone sculpting, 50% (one subject) and 100% (two subjects) exceeded the Korean OEL and ACGIH-TLV, respectively, but the area sample did not exceed either OEL. During wood sculpting, two subjects (40%) exceeded ACGIH TLV. Conclusions: This work evaluated the sculptors' exposure to particulate matter and noise in fine art college, and revealed a poor working environment for the participating students. Effective measures should be supplemented by the administration of colleges.

• Korean Journal of Social Welfare
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• v.53
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• pp.129-153
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• 2003

This study examines the socio-economic impacts of recent welfare reform in the United States. Based on the neo-conservative critique to the traditional public assistance system for low-income families, the 1996 welfare reform has given greater emphases on reducing welfare dependency and increasing work effort and self-sufficiency among welfare recipients. In particular, the welfare reform legislation instituted 60-month lifetime limits on cash assistance, expanded mandatory work requirements, and placed financial penalties for noncompliance. With the well-timed economic boom in the second half of the 1990s, the welfare reform seems to achieve considerable progress; welfare caseload has declined sharply to reach less than 50% of its 1994 peak, single mothers' labor force participation has increased substantially, and child poverty has decreased. In spite of these good signals, the welfare reform also has several potential problems. Many welfare leavers participate in the labor market, but not all (or most) of them. The economic well being of working welfare leavers did not increased significantly, because earnings increase was canceled out by parallel decrease in welfare benefits. Furthermore, most of working welfare leavers are employed in jobs with poor employment stability and low wages, making them highly vulnerable to frequent layoff, long-time joblessness, persistent poverty, and welfare recidivism. Another serious problem of the welfare reform is that a substantial number of welfare recipients are faced with extreme difficulties in finding jobs, because they have severe barriers to employment. The new welfare system with 5-year time limit can severely threaten the livelihoods of these people. The welfare reform presupposes that welfare recipients can achieve self-reliance by increasing their labor market activities. However, empirical evidences suggest that many people are unable to respond to the new, work-oriented welfare strategy. It may be a very difficult task to achieve both objectives of the welfare reform((1) providing adequate income security for low-income families and (2) promoting self-sufficiency) at the same time, because sometimes they are conflicting each other. With this in mind, a possible solution can be to distinguish welfare recipients into "(Very)-Hard-to-Employ" group and "(Relatively)-Ready-to-Work" group, based on elaborate examinations of a wide range of personal conditions. For the former group, the primary objective of welfare policies should be the first one(providing income security). For the "Ready-to-Work" group, follow-up services to promote job retention and advancement, as well as skill-training and job-search services, are very important. The U. S. experiences of the welfare reform provide some useful implications for newly developing Korean public assistance policies for the able-bodied low-income population.

• The Korean Journal of Nuclear Medicine Technology
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• v.19 no.1
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• pp.30-36
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• 2015

Purpose Whole body bone scan, which makes up a largest percentage of nuclear medicine tests, has high sensitivity and resolution about bone lesion like osteomyelitis, fracture and the early detection of primary cancer. However, any standard for valuation has not yet been created except minimum factor. Therefore, in this study, we will analysis the method which show a quantitative evaluation index in whole body bone scan. Materials and Methods This study is conducted among 30 call patients, who visited the hospital from April to September 2014 with no special point of view about bone lesion, using GE INFINIA equipment. Enumerated data is measured mainly with patient's whole body count and lumbar vertabrae, and the things which include CNR (Contrast to Noise ratio), SNR (Signal to Noise ratio) are calculated according to the mean value signal and standard deviation of each lumbar vertabrae. In addition, the numerical value with the abdominal thickness is compared to each value by the change of scan speed and tissue equivalent material throughout the phantom examination, and compared with 1hours deleyed value. Completely, on the scale of ten, 2 reading doctors and 5 skilled radiologists with 5-years experience analysis the correlation between visual analysis with blind test and quantitative calculation. Results The whole body count and interest region count of patients have no significant correlation with visual analysis value throughout the blind test(P<0.05). There is definite correlation among CNR and SNR. In phantom examination, Value of the change was caused by the thickness of the abdomen and the scan speed. And The poor value of the image in the subject as a delay test patient could be confirmed that the increase tendency. Conclusion Now, a standard for valuation has not been created in whole body bone scan except minimum factor. In this study, we can verify the significant correlation with blind test using CNR and SNR and also assure that the scan speed is a important factor to influence the imagine quality from the value. It is possible to be some limit depending on the physiology function and fluid intake of patient even if we progress the evaluation in same condition include same injection amount, same scan speed and so on. However, that we prove the significant evaluation index by presenting quantitative calculation objectively could be considered academic value.

• 한국노년학
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• v.36 no.3
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• pp.905-926
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• 2016

Although the concept of the elderly varies depending on scholars and laws, as consumption expenditure is deeply associated with income due to the nature of this study, 55 years old was set as the low limit standard for the elderly according to Prohibition of Discrimination on Age in Employment and Employment Promotion for the Aged Act and the elderly households were limited to single-elderly person household and an elderly couple family household for this study. It is considered consumption characteristics as a significant analysis subject in terms of social welfare because it could be understood as an expressed need which was a reflection of desire. Therefore, the present study aimed to investigate the consumption characteristics of the elderly households by stereotyping the consumption pattern of the elderly households, and find the determining factors for consumption patterns and thus contribute to the establishment of related policies through the expressed needs of the elderly households. K-means of cluster analysis was performed by putting the consumption expenditure of the elderly households to investigate inherent structural type of consumption pattern of the elderly households, which were the investigation subjects. As a result, four groups were stereotyped and named as below: 'health care-centered type', 'saving-centered type', 'livelihood-centered type', and 'food expenses-centered type' Binary Logistic Regression analysis was used to identify the factors that influence the decision of consumption pattern of the elderly households. The result of study showed that the elderly households faced all different needs and problems and thus there is a need for various approach plans to solve this situation. In particular, although the elderly have been viewed as economically poor people so far, the study showed that there were also kind of prepared households through saving. Overall, livelihoodcentered type accounted for the highest portion and, as a factor that influenced this, marital state and household income played an important role. Therefore, it is considered that more active efforts to increase the income of the elderly households are needed. In addition, age, owning of house and subjective health state were found to also have significant influence. Through these results of the study, the elderly's own improvement of awareness on health, presentation of overall standard for health state of the elderly, securement of the elderly's access to cultural life, and financial management coordination for improvement of quality of life, development and dissemination of jobs suitable for the elderly, and dissemination of communal life household, which is a cooperation residential type, were presented as institutional task in the conclusion.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.3
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• pp.283-298
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• 2022

In this study, we investigated the mineral geochemistry of the albite-spodumene pegmatite, associated exogreisen, and wall rock from the Boam Li deposit, Wangpiri, Uljin, Gyeongsangbuk-do, South Korea. The paragenesis of the Boam Li deposit consists of two stages; the magmatic and endogreisen stages. In the magmatic stage, pegmatite dikes mainly composed of spodumene, albite, quartz, and K-feldspar intruded into the Janggun limestone formation. In the following endogreisen stage, the secondary fine-grained albite along with muscovite, apatite, beryl, CGM(columbite group mineral), microlite, and cassiterite were precipitated and partly replaced the magmatic stage minerals. Exogreisen composed of tourmaline, quartz, and muscovite develops along the contact between the pegmatite dike and wall rock. The Cs contents of beryl and muscovite and Ta/(Nb+Ta) ratio of CGM are higher in the endogreisen stage than the magmatic stage, suggesting the involvement of the more evolved melts in the greisenization than in the magmatic stage. Florine-rich and Cl-poor apatite infer that the parental magma is likely derived from metasedimentary rock (S-type granite). P₂O₅ contents of albite in the endogreisen stage are below the detection limit of EDS while those of albite in the magmatic stage are 0.28 wt.% on average. The lower P₂O₅ contents of the former albite can be attributed to apatite and microlite precipitation during the endogreisen stage. Calcium introduced from the adjacent Janggun formation may have induced apatite crystallization. The interaction between the pegmatite and Janggun limestone is consistent with the gradual increase in Ca and other divalent cations and decrease in Al from the core to the rim of tourmaline in the exogreisen.

• Journal of the Korean Wood Science and Technology
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• v.16 no.2
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• pp.1-41
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• 1988

For the purpose of utilizing the sawdust having poor combining properties as board raw material and resulting in dimensional instability of board, polypropylene chip (abbreviated below as PP chip) or oriented PP thread was combined with sawdust particle from white meranti(Shorea sp.). The PP chip was prepared from PP thread in length of 0.25, 0.5, 1.0 and 1.5 cm for conventional blending application. Thereafter, the PP chip cut as above was combined with the sawdust particle by 3, 6, 9, 12 and 15% on the weight basis of board. Oriented PP threads were aligned with spacing of 0.5, 1.0 and 1.5cm along transverse direction of board. The physical and mechanical properties on one, two and three layer boards manufactured with the above combining conditions were investigated. The conclusions obtained at this study were summarized as follows: 1. In thickness swelling, all one layer boards combined with PP chips showed lower values than control sawdustboard, and gradually clear decreasing tendendy with the increase of PP chip composition. Two layer board showed higher swelling value than one layer board, but the majority of boards lower values than control sawdustboard. All three layer boards showed lower swelling values than control sawdustboard. 2. In the PP chip and oriented thread combining board, the swelling values of boards combining 0.5cm spacing oriented thread with 1.0 or 1.5cm long PP chip in 12 and 15% by board weight were much lower than the lowest of one or three layer. 3. In specific gravity of 0.51, modulus of rupture of one layer board combined with 3% PP chip showed higher value than control sawdustboard. However, moduli of rupture of the boards with every PP chip composition did not exceed 80kgf/cm2, the low limit value of type 100 board, Korean Industrial Standard KS F 3104 Particleboards. Moduli of rupture of 6%, 1.5cm-long and 3% PP chip combined boards in specific gravity of 0.63 as well as PP chip combined board in specific gravity of 0.72 exceeded 80kgf/$cm^2$ on KS F 3104. Two layer boards combined with every PI' chip composition showed lower values than control sawdustboard and one layer board. Three layer boards combined with.1.5cm long PP chip in 3, 6 and 9% combination level showed higher values than control sawdustboard, and exceeded 80kgf/$cm^2$ on KS F 3104. 4. In modulus of rupture of PP thread oriented sawdustboard, 0.5cm spacing oriented board showed the highest value, and 1.0 and 1.5cm spacing oriented boards lower values than the 0.5cm. However, all PP thread oriented sawdustboards showed higher values than control saw-dustboard. 5. Moduli of rupture in the majority of PP chip and oriented thread combining boards were higher than 80kgf/$cm^2$ on KS F 3104. Moduli of rupture in the boards combining longer PP chip with narrower 0.5cm spacing oriented thread showed high values. In accordance with the spacing increase of oriented thread, moduli of rupture in the PP chip and oriented thread combining boards showed increasing tendency compared with oriented sawdustboard. 6. Moduli of elasticity in one, two and three layer boards were lower than those of control sawdustboard, however, moduli of elasticity of oriented sawdustboards with 0.5, 1.0 and 1.5cm spacing increased 20, 18 and 10% compared with control sawdustboard, respectively. 7. Moduli of elasticity in the majority of PP chip and oriented thread combining boards in 0.5, 1.0 and 1.5cm oriented spacing showed much higher values than control sawdustboard. On the whole, moduli of elasticity in the oriented boards combined with 9% or less combination level and 0.5cm or more length of PP chip showed higher values than oriented sawdustboard. The increasing effect on modulus of elasticity was shown by the PP chip composition in oriented board with narrow spacing. 8. Internal bond strengths of all one layer PP chip combined boards showed lower values than control sawdust board, however, the PP chip combined boards in specific gravity of 0.63 and 0.72 exceeded 1.5kgf/$cm^2$, the low limit value of type 100 board and 3kgf/$cm^2$, type 200 board on KS F 3104, respectively. And also most of all two, three layer-and oriented boards exceeded 3kgf/$cm^2$ on KS F. 9. In general, screw holding strength of one layer board combined with PP chip showed lower value than control sawdustboard, however, that of two or three layer board combined with PP chip did no decreased tendency, and even screw holding strength with the increase of PP chip composition. In the PP chip and oriented PP thread combining boards, most of the boards showed higher values than control sawdustboard in 9% or less PP chip composition.

• Journal of the Korean Wood Science and Technology
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• v.14 no.1
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• pp.3-44
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• 1986

In order to obtain the basic physical and mechanical properties of steel wire reinforced particleboard, particleboards were formed with large particles through 2.11 mm (12 meshes) and retained on 1.27mm (20 meshes) sieves and small particles through 1.27mm (20 meshes) and retained on 0.42mm (60 meshes) sieves from the plywood mill wastes of meranti (Shorea spp.) in the form of pallmanchips, applying urea-formaldehyde resin as an adhesive on the particle surface in 10 percent on the oven dried weight of particles, and arranging steel wires of 1mm in diameter 5,10,15,20, and 25mm in longitudinal and transverse direction with crossing in the mid of the board depth in single layer boards, 10mm in longitudinal or transverse direction without crossing in two layers and 10mm in longitudinal and transverse directions with and without crossing in three steel wire layers boards. The stepwise 9-minutes-multi-pressing schedule in 5 minutes at 35 kgf/$cm^2$, 2.5 minutes at 25 kgf/$cm^2$. and 1.5 minutes at 15 kgf/$cm^2$ was applied for $300{\times}200{\times}13$mm board at the temperature of 160$^{\circ}C$ in a hot press. Specific gravity, thickness swelling, bending properties of modulus of rupture (MOR), modulus of elasticity(MOE), work to proportional limit, and work to ultimate load, internal bond (IB), and screw holding power(SHP) of the reinforced boards were analyzed on the wire openings and wire layers. The results obtained are summarized as follows; 1) In specific gravity, particleboards with large particles and small particles had higher value with more steel wire placements and more steel layers composition, 2) Particleboards with large particles in accordance with more steel wire liners composition gave very poor thickness swelling. 3) The mechanical properties of particleboards formed with large or small particles were reinforced with more steel wire layers. Therefore, bending strength was improved in modulus of rupture, modulus of elasticity, and work to ultimate load. Especiallv, particleboards with two or three steel wire layers showed the tension lamination effect when the steels in lower steel wire layer were oriented parallel to the board length. 4) The modulus of rupture, modulus of elasticity, and work to ultimate load in bending varied with opening area, distance of lengthwise wires multipled by distance of transverse wires. Particleboards formed with large particles resulted in higher value in modulus of rupture with 1.5-3 $cm^2$ opening area, 1-2cm distance between transverse wires, and 1.5-2.5cm distance between lengthwise wires. Particle boards formed with small particles showed higher value with 0.5-1.5$cm^2$ or 3.75-6.25 $cm^2$ opening area, 0.5 or 2.5cm distance between transverse wires. 5) In modulus of elasticity, particleboards formed with large particles with one steel wire layer suggested higher value with 5-3$cm^2$ opening area, 1-2.5cm distance between transverse wires and also 1-2.5 cm distance between lengthwise wires. Particleboards formed with small particles showed higher value with 0.75-1.25$cm^2$ or 3-6.25$cm^2$ opening area and 0.5 or 2.5cm distance between transverse wires. 6) Particleboards formed with large particles gaved higher value in work to ultimate load with 1-3$cm^2$ opening area. Particleboards formed with small particles showed increasing tendancy with decreasing opening area. 7) In internal bond and screw holding power, particleboards formed with large particles had increasing value in two and three steel wire layers compositions, but particleboards formed with small particles showed no difference. Particleboards formed with large particles containing one steel wire layer showed no difference in internal bond and screw holding power, and particleboards formed with small panicles containing one steel wire layer resulted in increasing value in internal bond and decreasing value in screw holding power in accordance with increase in opening area.