• Journal of agricultural medicine and community health
• /
• v.16 no.1
• /
• pp.3-9
• /
• 1991

In order to find out status of health care for community residents with special reference to organization and man power in a rural health subcenter, a study was carried out, through analyzing the data, operated by health subcenter during 1973~1990 in a rural area, Su Dong-Myun, Nam Yang Ju-Gun, Kyung Gi-Do, Korea. The following results were obtained : l) The Number of Population in Su Dong-Myun is decreasing and household is increasing chronologically. 2) In 1989, the characteristics of population composition rate in Su Dong-Myun were shown : the groups of Age, 65 and over was high rate(9.8%) and 0~4 was low rate(5.3%) decreasing chronologically. 3) Since 1972, services of Su Dong-Myun health subcenter have been carried in the 3 functions(medical treatment, health care management and clerical work) with supports of Ewha Woman's University through the participation of community residents organization. 4) The Number of Su Dong-Myun health subcenter personnel in 1990 was 5 persons(public health doctor l, public health dentist l, health worker l, dental technician l and assistant nurse l) and of these, health worker who must have the huge charge of health care management, has been worked at Myun-office as a public official, in condition, decreased from 3 in 1980 to 2 in 1981 and from 2 to 1 in 1985. 5) Health service Activities of Su Dong Myun health subcenter obtained good results in it's achievement during 1975-1985, but since 1986, it has been in condition of lower stepping. 6) Since 1977, annual medical utilization rate showed decreasing tendency such as 900 per l,000 population in 1977, 846 in 1979, 723 in 1981, 343 in 1973 and 34l in 1987. 7) A proposal : (l) Organization of health subcenter must be unified and systematized by government, so that health subcenter can carry out primary health care for community residents through responsibilities and authorities. (2) Teaching programs in educational process must be reorganized, according to periodical request. considering relative importance to primary health care in health care needs of community residents.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.22 no.1
• /
• pp.117-124
• /
• 2009

The p-convergent boundary element method has been proposed to analyze two-dimensional potential problem on the basis of high order Legendre shape functions that have different property comparing with the shape functions in conventional boundary element method. The location of nodes corresponding to high order shape function are not defined along the boundary, called by nodeless node, similar to the p-convergent finite element method. As the order of shape function increases, the collocation point method is used to solve linear simultaneous equations. The collocation patterns of p-convergent boundary element method consist of non-symmetric hierarchial or symmetric non-hierarchical. As the order of shape function increases, the number of collocation point increases. The singular integral that appears in p-convergent boundary element has been calculated by special numeric quadrature technique and semi-analytical integration technique. The L-shape domain problem including singularity in the vicinity of reentrant comer is analyzed and the numerical results show that the relative error is smaller than $10^{-2}%$ range as compared with other results in literatures. In case of same condition, the symmetric p-collocation point pattern shows high accuracy of solution.

• Korean Journal of Environmental Agriculture
• /
• v.27 no.4
• /
• pp.382-388
• /
• 2008

This study was initiated to elucidate the relation between the toxicity of $Cr^{6+}$, $Zn^{2+}$, and $Cd^{2+}$ and sludge age (Solids retention time, SRT). The effect of SRT on the toxicity of $Cr^{6+}$, $Zn^{2+}$, and $Cd^{2+}$ in activated sludge system was investigated with INT-dehydrogenase assay. Experimental results showed that the inhibitory effects of $Cr^{6+}$, $Zn^{2+}$, and $Cd^{2+}$ were reduced as the sludge age increased from SRT 5 d to SRT 25 d. It is noteworthy that the experimental results enabled to determine the relative toxicity of the tested metals depending on the sludge age. At the SRT of 5 and 9 days, the order of toxicity of the three metals to the activated sludge was $Cr^{6+}$ > $Zn^{2+}$ > $Cd^{2+}$ (the $IC_{50}$ value of $Cr^{6+}$, $Zn^{2+}$, and $Cd^{2+}$ was 16.15, 25.90, and 32.49 mg/L, respectively) and $Zn^{2+}$ > $Cr^{6+}$ > $Cd^{2+}$ (the $IC_{50}$ value of $Cr^{6+}$, $Zn^{2+}$, and $Cd^{2+}$ was 39.12, 27.93, and 42.31 mg/L, respectively), respectively. However, the toxicity of three metals was almost same at the SRT of 14 and 25 days (the range of $IC_{50}$ in SRT 14 and 25 days was from 49.80 mg/ L to 53.44 mg/L among three heavy metals). This results would be explained by that the quantity of biopolymer formed in short SRT was small, whereas that in long SRT was large. Consequently, it is recommended that sludge age be maintained at long SRT in order to avoid the toxicity inhibition of heavy metals such as $Cr^{6+}$, $Zn^{2+}$, and $Cd^{2+}$.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.23 no.2
• /
• pp.96-102
• /
• 2009

In this paper, the effects of the position and the angle of the potential probes on the measurements of the ground resistance with the fall-of-potential method are described and the testing techniques to minimize the measuring errors are proposed. The fall-of-potential method is theoretically based on the potential and current measuring principle and the measuring error is primarily caused by the position and angle of auxiliary probes. In order to analyze the relative error for measuring value of ground resistance due to the position of the potential probe, ground resistance were measured in case that the distance of current probe was fixed at 50[m] and the distance of potential probe was located from l0[m] to 50[m]. Also, the potential probe was located at 30[$^{\circ}$], 45[$^{\circ}$], 60[$^{\circ}$], 90[$^{\circ}$] and 180[$^{\circ}$]. As a consequence, relative error decreased with increasing the distance of potential probe and decreasing the angle between current probe and potential probe. The results could be help to determine the position of potential probe when the ground resistance was measured at grounding system.

• Analytical Science and Technology
• /
• v.16 no.2
• /
• pp.125-133
• /
• 2003

In order to determine the contents of trans-resveratrol in red wine, which was mainly consumed in Korea, both LC/MS-ESI and LC/MS-APCI methods were used after solid-phase (Sep-Pak $C_{18}$-cartridges) extraction. The contents of trans-resveratrol obtained by LC/MS-ESI were detected in the range of $0.06-4.31{\mu}g/mL$. The recoveries were ranged from 88.4 to 97.9%. The values of relative standard deviation were ranged from 0.6 to 4.6% and the detection limit was $0.001{\mu}g/mL$. The contents of trans-resveratrol obtained by LC/MS-APCI were detected in the range of $0.09-4.02{\mu}g/mL$ and the detection limit was $0.005{\mu}g/mL$.

• Journal of The Korean Society of Integrative Medicine
• /
• v.10 no.3
• /
• pp.209-219
• /
• 2022

Purpose : The purpose of this study was two-fold: to investigate the effects of uncertainty and depression on the quality of life (QoL) of elderly people with chronic diseases and to provide basic data on the physical, emotional, and psychological factors affecting their QoL in the field of physical therapy. Methods : A questionnaire covering uncertainty, depression, and QoL was distributed among 320 elderly people. Pearson's correlation analysis was performed to examine the correlation between uncertainty (ambiguity, complexity, inconsistency, and unpredictability), depression, and QoL (physical, psychological, social, and living environment domains) of the respondents; furthermore, multiple regression analysis was performed to identify the factors affecting the QoL of the respondents with a chronic disease. Results : The sub-factors of uncertainty and QoL-"complexity and social domain" (r=-.295, p<.001), "complexity and living environment domain" (r=-.302, p<.001), and "inconsistency and living environment domain" (r=-.360, p<.001)-showed a negative (-) correlation, as did depression and the sub-factors of QoL-"depression and physical domain" (r=-.782, p<.001), "depression and psychological domain" (r=-.876, p<.001), "depression and social domain" (r=-.668, p<.001), and "depression and living environment domain" (r=-.731, p<.001). The factors affecting QoL were complexity (𝛽=-.122, p<.001), inconsistency (𝛽=-.102, p=.002), unpredictability (𝛽=.112, p<.001), and depression (𝛽=-.850, p<.001). The relative influence of the independent variables was in the order of depression, complexity, unpredictability, and inconsistency, and the explanatory power was 77.1 % (F=215.853, p<.001). Conclusion : It is important to help the elderly with chronic diseases reduce the negative impact on their quality of life by helping them gain support from their families and medical professionals and by increasing their understanding through communication so that they can transition from negative emotions to positive emotions of opportunity.

• Electrical & Electronic Materials
• /
• v.10 no.2
• /
• pp.150-155
• /
• 1997

Powder type electroluminescent device(P-ELD) in this study was prepared by printing method. P-ELDs were basically composed of phosphor, insulator and transparent conducting layer. The phosphor powder was prepared by sintering the mixture of ZnS as a host, Cu as an activator, and NaCl as a flux for co-activator and enhancement of growth of the phosphor particles. The phosphor layer was made by printing the paste of the cyanoethylpullan as a binder and the ZnS system phosphor powder. In order to evaluate the luminescence characteristics of ZnS P-ELD, applied voltage - luminance(V-L), frequency-luminance(f-L), and relative luminance spectra(L- .lambda.) characteristics were measured. The experimental results show that luminance increased with increasing the applied voltage and frequency. It can be explained in terms of the potential barrier formed between ZnS and CuS. Two emission peaks in luminance-wavelength spectra measured at applied voltage of 100 $V_{rms}$ were observed at 500nm as a primary peak and 460nm as a secondary peak, respectively.y.

• Advances in aircraft and spacecraft science
• /
• v.6 no.3
• /
• pp.225-238
• /
• 2019

A spike attached to a blunt nosed body significantly alters its flow field and influences the aerodynamic coefficients at hypersonic speed. The basic body is an axisymmetric, with a hemisphere nose followed by a cylindrical portion. Five different types of spikes, namely, conical aerospike, hemisphere aerospike, flat-face aerospike, hemisphere aerodisk and flat-face aerodisk are attached to the basic body in order to assess the aerodynamic characteristic. The spiked blunt body without the aerospike or aerodisk has been set to be a basic model. The coefficients of drag, lift and pitching moment were measured with and without blunt spike body for the length-to-diameter ratio (L/D) of 0.5, 1.0, 1.5 and 2.0, at Mach 6 and angle of attack up to 8 degrees using a strain gauge balance. The measured forces and moment data are employed to determine the relative performance of the aerodynamic with respect to the basic model. A maximum of 77 percent drag reduction was achieved with hemisphere aerospike of L/D = 2.0. The comparison of aerodynamic coefficients between the basic model and the spiked blunt body reveals that the aerodynamic drag and pitching moment coefficients decrease with increasing the L/D ratio and angle of attack but the lift coefficient has increasing characteristics.

• Tribology and Lubricants
• /
• v.17 no.2
• /
• pp.146-152
• /
• 2001

Environmentally adapted synthetic base oils of polyalkylene glycols (PAGs) and polyol esters (POEs) show a high polarity because of their functional groups containing oxygen atom. The lubricating performance of these polar base oils was investigated by using a four-ball tribometer under boundary lubrication condition. Four polyalkylene glycols and five polyol ester base oils were used as sample base oils of high polarity. A mineral oil (MO) and alkylnaphthalene (AN) were used as low polarity base oils. Tricrecylphosphate (TCP) was added to all the base oils, in the range of 10 mmol/L-2000 mmol/L, as an antiwear additive. All the TCP-for-mutated base oils showed optimum concentration characteristics for minimizing wear. The order of optimum concentration of all the base oils was in a good accordance with the order of relative stability of TCP in base oils. The interaction model on solvation between additive and different polar base oils can expect the stability order of TCP. Thus, the model on solvation can explain well the order of optimum concentration of all the base oils, by using the effect of polarity (dielectric constant, $\varepsilon$) and molecular size (molecular weight, MW) of them on stability of TCP in polar base oils. Finally, a good correlation of the optimum concentration for all the base oils was obtained when it was arranged as a function of C∝(M $W_{Base Oil}$/M $W_{TCP}$)$^{-2}$.71/.($\varepsilon$$_{Base Oil}$)$^{3.38}$ by these two parameters.s..

• Journal of Wetlands Research
• /
• v.16 no.4
• /
• pp.353-362
• /
• 2014

The purpose of this study is to investigate the effect of micro-topography to vegetation pattern in Dunchon-dong wetland. To characterize the effect of micro-topography, changes in water level and vegetation pattern were monitored from 2007 to 2008. Depending on the relative elevation, the study site was divided into 4 sectors. The relative areas of sectors in ascending order were 11%, 10%, 18% and 24%, respectively. During investigation period, average water pH was 6.10 (${\pm}0.13$), electron conductivity was $51.5({\pm}6.0){\mu}s/cm$, $PO_4$-P, $NO_3$-N and $NH_4$-N concentration were $0.04({\pm}0.02)mg/L$, $0.14({\pm}0.07)mg/L$, and lower than 0.01mg/L, respectively. Water level was very changeable in low-water season because the area of lowest sector was small. This characteristic increased the effect of difference of accumulated precipitation from March to April in 2007 and 2008 to plant community composition in lower sectors. Different plant guilds dominated respective sectors and annual plants were major dominant species in the study site. This study suggested that the elevation gradients are necessary to create the habitats for various plant guilds in wetland.