• Analytical Science and Technology
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• v.13 no.4
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• pp.466-473
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• 2000

The complex formation constants (${\beta}_{MLn}$) of potassium and various sodium-selective neutral carriers in solvent polymeric membranes have been determined using solvent polymeric membrane-based optodes and ion-selective electrodes (ISEs). Two different types of PVC-based membranes containing the H^+selective chromoionophore (ETH 5294) with and without a sodium ionophore (4-tert-bntylcalix[4]arenetetraacetic acid tetraethyl ester, ETH 2120, bis[(12-crown-4)methyl] dodecylmethylmalonate or monensin methyl ester) were prepared and their optical responses to either the changes in alkali metal cation (e.g., sodium and potassium) concentrations at a fixed pH (0.05 M Tris-HCl, pH 7.2) or varying pH at a fixed alkali metal cation concentration (0.1 M) were measured. The same type of membranes were also mounted in conventional electrode body and their potentiometric responses to varying pH at a fixed alkali metal cation concentration (0.1 M) were measured. The complex formation constants of the ligand could be calculated from the calibration plots of the relative absorbance vs. the activity ratios of cation and proton ($a_{M^+}/a_{H^+}$) and of the emf vs. pH. It was confirmed that the ratio values of the complex formation constants for the primary and interfering ions are closely related to the experimental selectivity coefficients of ISEs.

• Analytical Science and Technology
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• v.18 no.6
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• pp.552-558
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• 2005

A type of dimethyl sulfide gas CRM in the ppb level was developed for the analysis of trace-level odorous gas in environmental atmosphere. The concentration of dimethyl sulfide ($(CH_3)_2S$) was 10 umol/mol level in the cylinder filled with nitrogen, 1500 psi. And the variability of the concentration for 3 years was about 0.1% due to the adsorption or instability of $(CH_3)_2S$. The gas standards produced simultaneously in 4 bottles and examined by GC-FID were shown with 0.4%, reproducibility of preparation and 0.25%, standard uncertainty due to weighing and purity. The relative expended uncertainty of 1.1% (95% of confidence level, k=2) was assigned to the certified value of 10 umol/mol level of $(CH_3)_2S$ after quantitative evaluation on the purity, mixing, weighing, analysis, adsorption and stability of dimethyl sulfide gas.

• Journal of Bio-Environment Control
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• v.6 no.1
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• pp.48-54
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• 1997

Among the various vegetables eggplant and gourd family can stand against high temperature environmental condition, about 35$^{\circ}C$. However, most of greenhouse farmers are giving up crop cultivation during hot summer season due to extreme temperature, 4$0^{\circ}C$ or above, condition of greenhouse interior. To improve this inferior crop growth condition, for nozzle system was installed in the pet greenhouse and the effect of fog system was investigated in order to determine fog water amount and the required fog nozzle numbers according to house volumes. MEE fog nozzle was selected for this Investigation which can produce water particle size of 27${\mu}{\textrm}{m}$ with water amount of 100$m\ell$ at pumping pressure of 70kg/$\textrm{cm}^2$. House cooling test was conducted in the pet greenhouse with one minute fogging and one minute air ventilation without stopping. It maintained 32$^{\circ}C$ at the house interior when the atmosphere and the house temperature were 35 and 4$0^{\circ}C$, respectively. And, an experimental equation was developed through calculating the changes of relative humidity and temperature with psychrometric equation which revealed the moisture transfer pattern between the house air and fog system. It showed that the required water fogging amounts to reduce 1$0^{\circ}C$, 40 to 3$0^{\circ}C$, needs 80.7$\ell$ for 1-2W(8,350㎥) and 99.9$\ell$ for 3-2G-3S(10,330㎥) type greenhouse with particle size of 27${\mu}{\textrm}{m}$.

• Journal of Korea Technology Innovation Society
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• v.15 no.1
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• pp.47-75
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• 2012

Basic research have contributed to technological growth or economic growth in U.S. Specially recent studies say that universities also contribute to economic development through scientific activities like science research, education, technology transfers. But we can not assure whether scientific knowledge was connected to real technology or economic performance, and it is difficult to figure out the effect of scientific output. "What is the exact performance of scientific knowledge?" It is still obscure. In this context, this paper analyzes characteristics of the linkage of science and technology. Data are U.S. R&D expenditure, scientific articles, citation of articles in U.S. patents by fields and sectors. As a result, university sector has the most weight of the linkage of science and technology. But, in relative connection rate analysis, industrial sector's is stronger than any other sectors. In the field analysis, linkage of science and technology is very strong in Chemistry, Physics, Biological sciences fields. And recently the linkage was increased in the fields of Computer science, Agricultural science, Engineering. Finally, this paper supports funding policy or estimation policy of government to product of scientific knowledge. University sector is still important because it has the most weight of the linkage. Scientific knowledge of industrial sector is also important. The connection rate of industrial science is the strongest in all sectors. And this research classify the R&D type by science fields. Considering the differences of science fields is needed to product science knowledge effectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.637-644
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• 2016

This paper is a follow-up to previous papers entitled, "Development of Tunnel-Environment Monitoring System and Its Installation" I [1] and II [2]. The target tunnel of these studies is the Solan Tunnel, which is a loop-type, single-track, 16.7-km-long tunnel located in mountainous terrain and passing through the Baekdudaegan mountain range. It is an ordinary railway tunnel designed for both freight and passenger trains. We analyzed the environmental conditions of the tunnel using temperature and humidity data recorded over approximately one year. The data were recorded using the Tunnel Rough Environment Measuring System (TREMS), which measures environmental data in subway and high-speed train tunnels and is installed in three locations inside the tunnel. Previous studies analyzed environmental conditions inside tunnels located in or near a city, whereas the tunnel in this study is located in a mountainous area. The tunnel conditions were compared with those measured outside the tunnel for each month. Hourly changes during summer and winter periods were also analyzed, and the environmental conditions at different locations inside the tunnel were compared. The results are widely applicable in studies on the thermal environment and air quality of tunnels, as well as for computer analysis of tunnel airflow such as tunnel ventilation and fire simulations.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.30 no.1
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• pp.159-169
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• 2012

Seokgasan(石假山) is originated in Goryeo, is a Korean traditional technique handed down to Joseon and Seokgasan is the Korean creative culture of gardening by artificial stones, which replicates small artificial mountain of natural landscape in the garden. The object of this study is Seokgasan made by Seong-im(成任), who was a civil minister in Joseon and lived from 1421 to 1484, in his residence located in Inwang Mountain, Hanyang and the purpose of this study is to investigate the historical meaning and symbol of Seokgasan made by Seong-im on the base of the relative old literatures and embody its shape and structure. According to the result of this study on Seokgasan of Seong-im, it can find out some facts as follows; Seokgasan of Seong-im in the early Joseon succeeded to the structural form of Seokgasan of the artificial rock mountain type connected pond, which was made-up firstly in the garden of the Palace of Manwoldae in the Middle Goryeo, and it was called firstly as 'Seokgasan' in the garden of Seong-im's house. Seong-im's Seokgasan in the early Joseon had more concentrated philosophical meanings, including the idea of taoist immortal, than those in the Goryeo dynasty and was be emblematic of an imaginative space. Also there were lots of gardens modeled on the famous mountains and famous lakes in China much the same as the Goryeo dynasty. In addition, there was an exceptional purpose for building Seokgasan which could not be found in the Goryeo dynasty. That was practicality for emotional stability and cure. Seong-im's Seokgasan is record-relics with high value of landscape architecture history, which can identify its historical meanings, shapes and structural frames succeeded from the Goryeo dynasty.

• Journal of Korean Society of Steel Construction
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• v.18 no.2
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• pp.213-223
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• 2006

Conventional truss optimization approaches, while often sophisticated and computationally intensive, have been applied to simple, minimum weight-cost models. These approaches do not perform well when applied to real-world trusses, which have costmodels that are complex and which often involve multiple objectives. Thus, this paper describes the optimization strategies that a clustering technique, which identifies members that are likely to have the same product type, uses for the optimal design of truss structures with real- world cost functions that consider the costs on the weight of the truss, the number of products in the design, the number of joints in the structures, and the costs required in the site.At first, the clustering technique is applied to identify the members and to generate a proper initial solution. A simple taboo search technique is then used, which attempts to generate the optimal solution by starting with the solution from the previous technique. For example, the proposed approach is a plied to a typical problem and to a problem similar to relative performances. The results show that this algorithm generates not only better-quality solutions but also more efficient ones

• Tribology and Lubricants
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• v.27 no.6
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• pp.308-313
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• 2011

In this study, friction tests were performed in order to investigate the effect of sliding velocity and normal load on the friction characteristics of DLC (a-C:H) and WC/C (a-C:H:W) using a ball-on-disk type friction tester. DLC and WC/C were deposited on AISI 52100 steel balls. Friction tests against carburized SCM 415 Cr-Mo steel disks were carried out under various sliding velocity (0.1, 0.78, 1.56, 3.13, 6.25, 12.5, 25, 50 and 100 mm/s) and normal load (2.4, 4.8 and 9.6 N) conditions while the relative humidity was 20~40 % R.H. and air temperature was $16{\sim}24^{\circ}C$. As results, kinetic friction coefficients of DLC and WC/C were obtained under each test condition. The results show that the kinetic friction coefficients of DLC and WC/C generally increase with the increase in sliding velocity. And, under the same sliding velocity condition, the kinetic friction coefficients are almost constant regardless of normal load. In addition, the kinetic friction coefficients of DLC are lower than those of WC/C under the same test conditions.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.457-457
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• 2010

Flexible organic light emitting diodes (F-OLEDs) requires excellent moisture permeation barriers to minimize the degradation of the F-OLEDs device. Specifically, F-OLEDs device need a barrier layer that transmits less than $10^{-6}g/m^2/day$ of water and $10^{-5}g/m^2/day$ of oxygen. To increase the life time of F-OLEDs, therefore, it is indispensable to protect the organic materials from water and oxygen. Severe groups have reported on multi-layerd barriers consisting inorganic thin films deposited by plasma enhenced chemical deposition (PECVD) or sputtering. However, it is difficult to control the formation of granular-type morphology and microscopic pinholes in PECVD and sputtering. On the contrary, atomic layer deoposition (ALD) is free of pinhole, highly uniform, conformal films and show good step coverage. Thus, $Al_2O_3/TiO_2$ multi-layer was deposited onto the polyethersulfon (PES) substrate by electron cyclotron resonance atomic layer deposition (ECR-ALD), and the water vapor transmission rates (WVTR) were measured. WVTR of moisture permeation barriers is dependent upon density of films and initial state of polymer surface. A significant reduction of WVTR was achieved by increasing density of films and by applying low plasma induced interlayer on the PES substrate. In order to minimize damage of polymer surface, a 10 nm thick $TiO_2$ was deposited on PES prior to a $Al_2O_3$ ECR-ALD process. High quality barriers were developed from $Al_2O_3$ barriers on the $TiO_2$ interlayer. WVTR of $Al_2O_3$ by introducing $TiO_2$ interlayer was recorded in the range of $10^{-3}g/m^2.day$ at $38^{\circ}C$ and 100% relative humidity using a MOCON instrument. The WVTR was two orders of magnitude smaller than $Al_2O_3$ barriers directly grown on PES substrate without the $TiO_2$ interlayer. Thus, we can consider that the $Al_2O_3/TiO_2$ multi-layer passivation can be one of the most suitable F-OLEDs passivation films.

• Journal of Food Hygiene and Safety
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• v.29 no.4
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• pp.253-259
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• 2014

This study was conducted to investigate survival of Bacillus cereus (B. cereus) on stainless steel and polyvinyl chloride (PVC) and its transfer from two material to lettuce. The stainless steel and PVC were innoculated with B. cereus and stored at 6 combination conditions (temperature : $20^{\circ}C$ and $30^{\circ}C$, relative humidity (RH) : 43%, 69%, and 100%). Although the total numbers of B. cereus at RH 43% and RH 69% were reduced by 3.53-4.00 log CFU/coupon within 24 h regardless of material type, the spore numbers of B. cereus was lasted at 3.0 log CFU/coupon. When two materials were stored at $30^{\circ}C$, RH 100%, the spore numbers of B. cereus was rapidly increased by 3.0 log CFU/coupon. In addition, the reduction rate of B. cereus was decreased in the presence of organic matter. Transfer rate of B. cereus from surface of stainless steel and PVC to lettuce was increased by 10 times in the presence of water on the lettuce surface. As a result of this study, the presence of B. cereus on produce contact surfaces can increase the risk of cross-contamination. Thus, it is important that the packing table and conveyer belt in post harvest facility should be properly washed and sanitized after working to prevent cross-contamination.