• Water for future
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• v.19 no.2
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• pp.157-166
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• 1986

The objective of this study was to determine the best representative synthetic unit hydrograph that is applicable to ungaged small watershed. A typical unit hydrograph was established with the actual data from a small watershed. Four currently well-known methods for analyzing ungaged small watershed, including Snyder's, Clark's S.C.S. and Nash methods, were evaluated with the data from the same small watershed. The following observations were noted from the analysis of four methods. The Snyder's method yielded the similar peak discharge value as the typical unit hydrograph. With co-ordinates of three discharge values, i.e. 25%, 50% and 75% of peak discharge, were not adequate for deriving a typical unit hydrograph in ungaged small watershed. With Clark's method there shall be some way of obtaining the exact base length of time area diagram and isochrone of each reach of the stream. With Nash method peak discharge and base flow time are affected by the storage constant and gamma function argument; therefore, for deriving a more reliable and workable unit hydrograph one needs to select for the better estimation of storage constant and gamma function argument. In S.C.S. method peak discharge is directly related to the watershed area and inversely related to the time of peak diacharge. Therefore area with faster peak discharge yielded the higer peak discharge value. Although the peak discharge value obtained frome the S.C.S. method higher than the value obtained from the unit hydrograph developed from the actual data, this method contains a number of advantageous factors. The peak discharge value and the time of peak discharge can be claculated easity from the morphological characteristics of the watershed, and in S.C.S method co-ordinates of the unit hydrograph can be calculated easily from that of the dimensionless unit hydrograph. When the four currently used methods were evaluated with a typical unit hydrograph obtained from the actual data, the S.C.S method was show to be the best method in deriving a synthetic unit hydrograph for ungaged small watershed.

• Journal of Wetlands Research
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• v.16 no.4
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• pp.319-325
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• 2014

A lot of Pond Wetland (Palustrine Wetland) are distributed in agricultural landscapes, Korea. These wetlands are evaluated as important resources for conservation of biodiversity. However, the study of Pond Wetland is rarely conducted except type classification in Korea. In this study, the function of pond wetland as ecosystem services is studied for conservation and utilization of wetland. Research was conducted in three steps; functionality analysis, functionality derivation, and importance analysis. A total of 22 features were derived by analyzing the previous studies. As a result of expert survey, 4 features were selected by each in the field of biological, environmental, and socio-culture among the 22 features. Importance was calculated by conducting a cross-functional features using Analytic Hierarchy Process (AHP). Finally, 10 ecosystem service functions of pond wetland were derived through expert survey; (1) Water Storage & Irrigation, (2) Vegetation Diversity, (3) Amphibian & Reptile Habitat, (4) Water Purification, (5) Aquatic Insect Habitat, (6) Nutriments Control was derived, (7) Groundwater Recharge, (8) Fishery Habitat, (9) Eco-Experience & Education, and (10) Aesthetic landscape. It is expected that this study is able to utilize in evaluation of pond wetlands ecosystem services by further study on analysis of functional importance and economic value index.

• Journal of Korea Water Resources Association
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• v.41 no.2
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• pp.229-239
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• 2008

This study is to derive the fourth-order Geomorphologic Instantaneous Unit Hydrograph (GIUH), driven for only third-order basin, for the application of GIUH to various types of basin. The second, third, and fourth order GIUHs were compared for various topographical conditions. The results showed lower peak runoff and later peak time in GIUH with higher stream order. Initial state probability was estimated from a function of geomorphologic parameters such as area ratio and bifurcation ratio for the application of GIUH. However, initial state probabilities and early parts of the GIUHs have negative values for many basins due to the inherent errors in the parameters. Initial state probability was calculated by area ratio of direct drainage using ArcView GIS 3.2 model to solve the problem. GIUHs were estimated for three basins, Sanganmi, Byeongcheon, and Sangye, using the above suggested method, and the results showed that the method is free of the problem.

• The Korean Journal of Petroleum Geology
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• v.1 no.1 s.1
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• pp.47-52
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• 1993

A method and results of computations are presented for the 2-D seismic migration process in the frequency-wavenumber domain for the laterally and vertically inhomogeneous medium. In order to take the intrinsic attenuation effect into account in the migration process the complex-valued wave velocity is used in the wavefield extrapolation operator, improving the generalized frequency-wavenumber migration technique. The imaginary part of the complex-valued wave velocity includes the seismic quality factor Q value. In derivation of the solution of the wave equation for the medium of inhomogeneous wave velocity and anelasticity, the inhomogeneous medium is mathematically converted to an equivalent system which consists of a homogeneous medium of averaged slowness and an inhomogeneous distribution of hypothetical wave source. The strength of the hypothetical wave source depends on the deviation of squared slowness from the averaged value of the medium. Results of numerical computation using the technique show more distinct geologic images than those using the convensional generalized frequency-wavenumber migration. Especially, the obscured images due to the wave attenuation by anelasticity are restored to show sharp boundaries of structures. The method will be useful in the imaging of the reflection data obtained in the regions of possible petroleum or natural gas reservoir and of fractured zone.

• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.1
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• pp.25-31
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• 2008

Information on daily maximum air temperature is important in predicting the status of plants and insects, but the uneven and sparse distribution of weather stations prohibits timely access to the data in regions with complex topography. Since cumulative solar irradiance plays a critical role in determining daily maximum temperature on any sloping surfaces, derivation of a quantitative relationship between cumulative solar irradiance and the resultant daily maximum temperature is a prerequisite to development of such estimation models. Air temperatures at 8 sideslope locations with similar elevation and slope angle but aspect, circumventing a cone-shaped, grass-covered parasitic volcano (c.a., 570 m diameter for the bottom circle and 90m bottom-to-top height), were measured from June to December in 2007. Daily maximum temperatures from each location were compared with the average of 8 locations (assumed to be the temperature measured at a "horizontal reference" position). The temperature deviation at all locations increased with the day of year (or sun elevation) from summer solstice to winter solstice. Averaged over the entire period, the south facing location was warmer by $1^{\circ}C$ in daily maximum temperature than "horizontal reference" and the north facing location was cooler by $0.8^{\circ}C$ than the reference, resulting in the year round average south-north temperature difference of $1.8^{\circ}C$. In November, both south and north facing slopes showed the greatest deviation of $+2.0^{\circ}C$ and $-1.3^{\circ}C$, respectively in daily maximum temperature at monthly scale. On a daily scale, the greatest deviation was +3.8 and $2.7^{\circ}C$ at the south and north slope, respectively. The cumulative solar irradiance (on the slope for 4 hours from 11:00 to 15:00 TST) explained >60% of the variance in daily maximum temperature deviations among 8 locations, suggesting a feasibility of developing an estimation model for daily maximum temperature over complex topography at landscape scales.

• Journal of Internet Computing and Services
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• v.17 no.3
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• pp.75-85
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• 2016

Changes in the distribution and sharing information using the Internet is changing the most part in our daily life, Utilizing the Internet of our lives to the rapid development of IT technology, are living in the off-line (off-line) and online (on-line) a mix of life, We expect now online life specific gravity is further increased. However, do not systematically implement the education of Internet ethics awareness deficiencies of objective indicators to assess the current knowledge level of the Internet ethics is the actual situation. Therefore, in this paper, it provides a development process in order to establish a common standard for the evaluation of Internet ethics index. Development procedure of Internet ethics index in order to establish a common standard, "evaluation item (draft) derivation", "Creating a questionnaire", "the calculation of the analysis and item-by-item weight of the questionnaire", and a common reference determination of the stage having. Was also a questionnaire that target 46 people to calculate the weight of the common reference. Internet ethics index evaluation model through the establishment of the common standards developed in this paper, municipal road Office of Education, related organizations, high school, such as small, medium, can be utilized as an indicator to measure the Internet ethics education level.

• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.3
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• pp.174-180
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• 2010

The inhomogeneous Helmholtz equation is introduced for variable water depth and potential function and separation of variables are introduced for the derivation. Only harmonic wave motions are considered. The governing equation composed of the potential function for irrotational flow is directly applied to the still water level, and the inhomogeneous Helmholtz equation for variable water depth is obtained. By introducing the wave amplitude and wave phase gradient the governing equation with complex potential function is transformed into two equations of real variables. The transformed equations are the first and second-order ordinary differential equations, respectively, and can be solved in a forward marching manner when proper boundary values are supplied, i.e. the wave amplitude, the wave amplitude gradient, and the wave phase gradient at a side boundary. Simple spatially-centered finite difference numerical schemes are adopted to solve the present set of equations. The equation set is applied to two test cases, Booij’ inclined plane slope profile, and Bragg’ wavy bed profile. The present equations set is satisfactorily verified against other theories including the full linear equation, Massel's modified mild-slope equation, and Berkhoff's mild-slope equation etc.

• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.3
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• pp.165-172
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• 2009

A set of equations for description of transformation of harmonic waves is proposed here. Velocity potential function and separation of variables are introduced for the derivation. The continuity equation is in a vertical plane is integrated through the water so that a horizontal one-dimensional wave equation is produced. The new equation composed of the complex velocity potential function, further be modified into. A set up of equations composed of the wave amplitude and wave phase gradient. The horizontally one-dimensional equations on the wave amplitude and wave phase gradient are the first and second-order ordinary differential equations. They are solved in a one-way marching manner starting from a side where boundary values are supplied, i.e. the wave amplitude, the wave amplitude gradient, and the wave phase gradient. Simple spatially-centered finite difference schemes are adopted for the present set of equations. The equations set is applied to three test cases, Booij's inclined plane slope profile, Massel's smooth bed profile, and Bragg's wavy bed profile. The present equations set is satisfactorily verified against existing theories including Massel's modified mild-slope equation, Berkhoff's mild-slope equation, and the full linear equation.

• Journal of Nutrition and Health
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• v.41 no.8
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• pp.887-899
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• 2008

Recently the Ministry of Health and Welfare, Republic of Korea, announced the “Dietary Guidelines for Korean Adults (DGKA)”, which includes ten Dietary Goals, six Dietary Guidelines, and twenty-three Action Guidelines. DGKA are developed as the revision of the 2003 Dietary Guidelines for Koreans, targeting adult population. Dietary Guidelines are developed for general purpose as well as for different age groups. They are revised periodically to accommodate changes in diet and health problems of the population. The process of developing new DGKA can be summarized as 1) selection of focus areas, 2) analysis and review of available data for each area selected, and 3) derivation of guidelines based on the analyzed data, and 4) finalizing the guidelines after open discussions among the experts and general public. Five focus areas were selected by examining the Nutrition Goals of the Health Plan 2010 of Korea, soliciting proposals from the experts in the related fields, and reviewing existing and international guidelines. Five areas selected were 1) adequate intake of nutrients and foods, 2) balance of energy intake and physical activities, 3) alcohol intake, 4) food security and nutrition service, and 5) food safety. Adequacy of nutrient and food intakes of the Korean adult population was assessed using 2005 Korea National Health and Nutrition Examination Survey (KNHANES) data. Newly developed Dietary Reference Intakes for Koreans were used as reference values to assess the prevalence of inadequacies and excesses in nutrient intakes. Energy balance was examined with energy intake of 2005 KNHANES survey and results of physical activity questionnaire in the survey. Alcohol intake was also examined using 2005 KNHANES results of dietary intakes as well as the results of questionnaire survey on alcohol intakes. Food security, nutrition services, and food safety were analyzed using various government data and published results on the issues. Ten Dietary Goals and six Dietary Guidelines were developed after data analysis and were subjected to reviews of experts and general public. The final DGKA are: 1) Eat a variety of foods from each food group, 2) Increase physical activity and maintain healthy weight, 3) Eat proper amount of clean foods, 4) Avoid salty foods and try to eat foods with bland taste, 5) Avoid foods with high fat contents and deep-fried foods, and 6) When you drink alcohol, limit the amount. Twenty-three action guidelines are developed in order to achieve these guidelines in actual diet and life among the population. The government is disseminating the guidelines with “337” slogan and emblem. “337” indicates everyone should practice “3” guidelines of promoting good eating practice, “3” guidelines to limit or decrease in your diet, and you should practice them for “7” days a week. The guidelines will be useful in promoting healthy food habits and good nutritional status which will result in decrease nutrition related health problems in Korea.

• Journal of the Korean Society of Clothing and Textiles
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• v.40 no.4
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• pp.746-762
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• 2016

This study considers expression techniques and aesthetic values in the images of head dress reflected in a natural motif. The conclusions of the study are as follows. The first type is the realistic expression (52.4%) such as the reproduction of a natural object's essential form (27.0%), the partial derivation of the natural object (19.3%), and the planarization for the actual image of the natural object (6.1%). The second type is a metaphorical expression (39.0%) which emphasizes the morphological characteristics of nature (18.2%), the structuration of the natural object's silhouette into a three-dimensional or two-dimensional form (11.5%), and the abstract expression of the form in the natural object (9.3%). The third type is a hybrid expression (8.6%) that is a compromise between practical (or metaphorical expressions) so that expression techniques represent a compromise between the natural object's essential form and abstract expression (4.6%) or the combination of the natural object's silhouette into a three-dimensional or a two-dimensional visualization (4.0%). Aesthetic head dress values reflected in the natural motif first indicate a primitive value. This state of natural instinct recreates the natural object or combines part of the biological elements of the natural object to create an inducement to escape from the practical world. The second is amusement in the expression of animals in dynamic and humorous forms creates an illusion of animals being alive with a representative playful enjoyment. The third is abstraction that grant freedom in the observer's aesthetic rational through a reinterpretation of the fashion designer. The fourth is eclecticism where a compromise represents an act of mixing a variety of independent factors to create harmony with the imagery of nature created through the grafting of diverse expression techniques that break away from stereotypes of existing natural objects to create a type of nature that cultivates new values.