• KIEAE Journal
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• v.7 no.4
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• pp.39-44
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• 2007

The purpose of this research is to study security of $CO_2$ exhaust at night in indoor air quality purifying system using plants. For this purpose, two same units for experiment were built, and difference of $CO_2$ exhaust by existence and nonexistence of plantation were measured. To reduce error by entrance of people, automatic measurement system were developed and used. At first, baseline were measured to check standard value, and next, $CO_2$ exhaust by plantation were measured. As a result, in baseline experiment, values of all spaces were steady as 400~500 ppm. When plantation was set-up, value of $CO_2$ at night was measured high as 150 ppm, and maximum value was around 600 ppm. This result is a lot lower than maximum standard of $CO_2$, 1000 ppm.

• Bulletin of the Korean Mathematical Society
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• v.47 no.1
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• pp.81-87
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• 2010

In this paper, we consider the existence of nontrivial solutions for the nonlinear fractional differential equation boundary-value problem(BVP) $-D_0^{\alpha}+u(t)=\lambda[f(t, u(t))+q(t)]$, 0 < t < 1 u(0) = u(1) = 0, where $\lambda$ > 0 is a parameter, 1 < $\alpha$ $\leq$ 2, $D_{0+}^{\alpha}$ is the standard Riemann-Liouville differentiation, f : [0, 1] ${\times}{\mathbb{R}}{\rightarrow}{\mathbb{R}}$ is continuous, and q(t) : (0, 1) $\rightarrow$ [0, $+\infty$] is Lebesgue integrable. We obtain serval sufficient conditions of the existence and uniqueness of nontrivial solution of BVP when $\lambda$ in some interval. Our approach is based on Leray-Schauder nonlinear alternative. Particularly, we do not use the nonnegative assumption and monotonicity which was essential for the technique used in almost all existed literature on f.

• Proceedings of the Technology Innovation Conference
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• 2004.02a
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• pp.108-131
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• 2004

Having the characteristics of public goods, Radio Spectrum had been controlled by Government Authorities. In the past, technological side of spectrum, such as cross protection, was the main concern, but as the telecommunication industry is developing gradually, economic side of spectrum is becoming an important part. To uplift the Economic efficiency of spectrum management policy, clarifying the basic value of spectrum is one of the most important things. Also, both government authorities and spectrum licensees will have to choose license or investment under uncertainties such as license timing, time to market, technology standard, and so on. Considering all things, this paper gives the value to the spectrum by real options theory, which is a powerful method concerning uncertainty, especially for government, And we applied it to a specific spectrum band for the portable Internet in Korea. These results can provide information about the technological standard, optimal market-entry time as well as the value of spectrum for the portable Internet.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.5
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• pp.65-70
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• 2012

The current-carrying capacities in IEC standards for underground refers to a soil thermal resistivity of 2.5[$K{\cdot}m/W$] where no measured data are available. But this value is considered too conservative and may not justifiable economically as to need precaution in using the value. In this paper, the standard practices on the application of soil thermal resistivity of some countries(UK, USA etc) are surveyed and proposed a reasonable representative value 1.0[$K{\cdot}m/W$] of soil thermal resistivity considering the domestic soil thermal properties with regard to the application of IEC standard.

• Journal of Korean Library and Information Science Society
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• v.45 no.4
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• pp.185-205
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• 2014

This study investigated IRA's 3 standards related to reading instruction and examined the value which can be meaningful to Korean situation. IRA divided reading educators into 7 types and proposed each detailed professional standard through the 'Standards for reading professionals'. The next standard called 'Standards for the English language art' described their direction and content for English language education including reading instruction. The 'Standards for the assessment of reading and writing' aims at the basis to evaluate students' reading ability. The value found through these standards is as follow: IRA's reading professionals standard can be a useful way to define the type of reading educator in Korea. A reading instruction standard like IRA's language art standard can guide reading instruction of Korean libraries in a more systemic and consistent way. A valid evaluation standard to measure students' reading ability can show the possibilities to define the students who struggle with reading and to provide more suitable instruction for them.

• Journal of The Korea Institute of Healthcare Architecture
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• v.23 no.1
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• pp.15-24
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• 2017

Purpose: Korea is expected to enter an aged society in 2018 and then a super-aged society in early 2025. The country's aging is progressing faster than any other country in the world. However, the foundation of the elderly friendly industry is weak, and measures at the government level are urgently needed. Especially, housing problems of the elderly are one of the most urgent measures to be taken. Korea does not have the minimum residential area standard for the elderly, and the current general minimum residential area standard is based on the survey of the housing situation without scientific evidence. Therefore, both standards need to be revised as soon as possible based on scientific evidence. Methods: The minimum residential area standard has been calculated following Karl H. E. Kroemer's Min or Max design also being called as-single cut and dual cut theory- as the maximum population value and minimum population value theory of Ernest J. McCormick. Therefore there is a need for a formula made using a few key factors, such as corresponding dimension, practical dimension, clearance, spare dimension, integrated dimension. These elements can be defined and used as formulas to calculate minimum residential area standards. Results: Assuming the results of the spatial variability in this study showed that it is possible to raise the standard of living in a terms of sustainable minimum size for the young, old and all residents. Implications: The government should set a minimum residential area standard with scientific grounds and set up a policy improving the life of people who live in an needy residential environment.

• Journal of Nutrition and Health
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• v.37 no.3
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• pp.193-201
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• 2004

The objective was to evaluate the factors influencing on the growth of children aged 3 - 6 years by mini dietary assessment and anthropometric indices in 556 children and by analyzing mineral contents of hair from 273 children by inductively coupled plasma mass spectrometry (ICP-MS). The mean concentration of zinc (Zn) in hair was 68.9 $\pm$ 31.1 ppm and the zinc level of 91 ％ children was less than 60％ of the reference value of 180 ppm. The mean content of lead (Pb) in hair was 1.76 $\pm$ 1.20 ppm, but only 67％ of 273 children was within the reference value of 2 ppm and the lead level of 33％ of children was 2 - 4 times higher than the reference value. The level of Zn was negatively correlated with Pb content (r = -0.305, p 〈 0.01). Hair Zn content, regardless of age, was significantly positively correlated with height (r = 0.214) and body weight (r = 0.159). The height of 95.3％ children was belonged to the normal range of 90 - 109.9％ of standard value and the body weight of 49.8％ children was in the range of 90 - 109.9％ of standard value. However, 8.1 ％ children was overweighted (110 - 119.9％ of standard) and 9.4％ children was obese (120 - 149.9％ of standard) and 0.9％ children was severe obese (〉 150％) which resulted in total 10.3％ obese. Contrary to our expectation, 32.8％ children was underweight (70 - 89.9％ of standard) and 36％ of the underweight children showed the low content of zinc (10 - 49 ppm) in hair. There was no significant correlation between dietary intake of Zn and hair Zn content. Hair Zn content was low even though children consumed greater than 75％ of their requirement for zinc. Regardless of dietary intake of Zn, hair Zn level was rather negatively correlated to the content of Pb in hair. 38.8％ children had an unbalanced diet which resulted in lower intake of calorie, Ca, Zn, vitamin B$_2$ compared with those consuming variety of foods. Therefore, it would be needed that new approach for nutrition education to improve eating habit having the unbalanced diet in preschool children. It might be also suggested to develop new food products to complement the nutrients of Zn, Ca, Fe as snacks or dietary supplement for Korean preschool children.

• 중국학논총
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• no.66
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• pp.45-61
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• 2020

Chinese for Journalism and Communication (CJC) is used not only to communicate, gather, read and understand the news and information in the daily life, but also to work as a professional in journalism. It includes daily CJC and professional CJC. It has similarities and difference with journalism terms. The lexical values of CJC words includes: recognition value, frequency value, composition value, and aggregation value.

• Aerospace Engineering and Technology
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• v.4 no.2
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• pp.209-215
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• 2005

A qualification of propellant for a AKM(Apogee Kick Motor) has been conducted by firing standard motors. The Standard motor used in developing process of KSLV-I's AKM is ST-6 whose diameter is about six inches. HTPB composite propellant are used in these motors. Several standard motors are fired and compared with simulation results. A mean value of characteristic velocity is 1518 m/s. The characteristic value for prediction is 1516 m/s, and the thrust loss is about 5.9%. Differences between the measurements and prediction are less than 3%.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.4
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• pp.421-428
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• 2011

It is challenging to survey the size and economical value of geospatial industry, because of the vagueness of the industry range. This study suggested a proposed method for the classification of geospatial industry based on Korea Standard Industry Classification, Th proposed method for the classification considered the value added chain of geospatial industry and Korean Standard Industry Classification, Theses considerations reflected characteristics of geospatial industry, Industrial statistics of geospatial industry are expected to be surveyed based on the classification proposed by this study,