• Toxicological Research
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• v.26 no.3
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• pp.177-183
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• 2010

This study was performed to examine whether elevated activity of cAMP responsive element-binding protein (CREB) attenuates the detrimental effects of acute gamma ($\gamma$)-irradiation on hippocampal neurogenesis and related functions. C57BL/6 male mice were treated with rolipram (1.25 mg/kg, i.p., twice a day for 5 consecutive days) to activate the cAMP/CREB pathway against cranial irradiation (2 Gy), and were euthanized at 24 h post-irradiation. Exposure to $\gamma$-rays decreased both CREB phosphorylation and immunohistochemical markers for neurogenesis, including Ki-67 and doublecortin (DCX), in the hippocampal dentate gyrus (DG). However, the rolipram treatment protected from $\gamma$-irradiation-induced decreases of CREB phosphorylation, and Ki-67 and DCX immunoreactivity in the hippocampal DG. In an object recognition memory test, mice trained 24 h after acute $\gamma$-irradiation (2 Gy) showed significant memory impairment, which was attenuated by rolipram treatment. The results suggest that activation of CREB signaling ameliorates the detrimental effects of acute $\gamma$-irradiation on hippocampal neurogenesis and related functions in adult mice.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.16 no.3
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• pp.152-161
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• 2004

Double-peak normal distribution function was suggested as the probability density function of the tidal elevation data in Korean coastal zone. Frequency distribution analysis was carried out using hourly tidal elevation data of the ten tidal gauging stations, i.e., Incheon, Kunsan, Mokpo, Cheju, Yeosu, Masan, Gadeokdo, Pusan, Pohang, and Sokcho which were served through the Internet Homepage by the National Ocean Research Institute. Based on the RMS error and $R^2$ value comparison analysis, it was found that this suggested function as the probability density function of the tidal elevation data was found to be more appropriate than the normal distribution function. The parameters of the double-peak function were estimated optimally using Levenberg-Marquardt method which was modified from the Newton method. The estimated parameters were highly correlated with the non-tidal constants of the tidal gauging stations.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.1
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• pp.9-16
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• 2010

The purpose of this study is to clarify the origin of organic matters on sediment and the characteristics of seasonal variation at an estuarine tidal flat. Silt-clay content (<63 ${\mu}m$), chlorophyll a, TOC, C/N ratio and the stable isotope ratio of carbon and nitrogen were measured at tidal flat around the estuary of the Nanakita River. As a result, organic matters originating from marine organic matter and bethic microalgae greatly contributed to sedimentation of organic matters at Stn.A, sandy tidal flat, though terrigenous organic matters did at Stn.C, muddy tidal flat. Furthermore, it was revealed that the volume and origin of organic matters in the sediments depended on seasonal variation, and the factors were different from the Stns, i.e. bentic microalgae and event for Stn.A, and the eventual sedimentation of organic matters originating from terrestrial plants, respectively.

• Journal of Ocean Engineering and Technology
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• v.19 no.4 s.65
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• pp.28-34
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• 2005

In the study application of volcanic scoria concrete to artificial reefs is investigated. Volcanic scoria is a natural volcanic product that shows light weight, mil/i-porous, and far-infrared irradiation characteristics. The properties of volcanic scoria concrete using Jeju scoria aggregate are evaluated by conducting a comprehensive series of tests on strength and void ratio. It is concluded that the volcanic scoria concrete has the sufficient strength of 4MPa-13MPa and adequate void ratio of $12\%-35\%$ to be accepted as artificial reef concrete. The field experiments are performed through observation by scuba diver's at the Seogwipo coast. Porous specimen and plane concrete specimen are prepared for comparison purposes. Seasonal changes of soft coral on the two series of test specimens were have been observed from Apr. 9, 2004 to Mar. 18, 2005. The soft coral is well grown on the porous specimen however there are no significant changes on the conventional plain concrete specimen. Thus it is concluded that the volcanic scoria concrete is highly suitable as artificial reef concrete.

• Korea Journal of Hospital Management
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• v.7 no.2
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• pp.24-36
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• 2002

The purpose of this paper is to find the factors affecting the number of patients per physician for a day at hospital and compare them with the results of previous studies. We used data of Korean national patients survey that had been carried out by central government and local health centers from October 27th to November 11th in 1999. Descriptive analyses were performed to overview the general characteristics of our study subject. Also, we tried to find the factors affecting the number of patients per physician for a day at hospital through t test and correlation analysis. Factors affecting the number of outpatients per physician for a day at hospital are location, training type, ownership, No. of physicians, No. of beds per physician, No. of physicists per physician, No. of nursing aids per physician and No. of medical technicians per physician. While factors affecting the number of inpatients per physician for a day at hospital are location, ownership, No. of physicians, No. of beds per physician, No. of pharmacists per physician, No. of nurses per physician, No. of nursing aids per physician and No. of administrative auxiliary personnels per physician. The most correlated variable with outpatients per physician for a day at hospital is No. of medical technicians per physician while the most correlated variable with inpatients per physician for a day at hospital is No. of beds per physician. A more detailed investigation is needed for verifying factors affecting the number of patients per physician for a day at hospital and other medical institutions.

• The Journal of Information Technology
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• v.3 no.1
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• pp.73-88
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• 2000

Dramatic changes are beginning to occur in plastic card technologies today in the fields of banking, health care, id-cards and more. Advanced card technologies such as IC-card are playing an increasingly important role in new and innovation system. The merit of IC-card are more capacity, more secure, more reliable, quick and easy to update, secure offline processing, enabling technology etc than magnetic stripe card. And so many countries began using experiment of IC- card and our country began October 13 in Cheju island. Then there are three types using-experiment (K-cash, VISA-cash, MONDEX) in Korea. There are some problems such as standards, widely using, high cost, double investment etc. I think that important things in IC-card using is an international- standardizations and issuing corporation.

• Journal of the Korea Convergence Society
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• v.9 no.7
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• pp.63-68
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• 2018

Research on smart farms centering on greenhouse cultivation is actively under way due to the decrease in agriculture population and aging, but in the case of vegetables such as vegetables, outdoor cultivation is 70%. Therefore, there is a need to improve productivity and prevent soil contamination by automating, cultivating, and intelligentizing the outdoor cultivation of agriculture crops. In this paper, we show the case of establishing a outdoor production system using the Internet of things and define the environmental variables in the outdoor production system. By measuring soil temperature, water content, electrical conductivity and acidity through sensors, LoRa communication module transmits the information to the outdoor production system. The outdoor production system controls the amount of fertilizer and the volume of water based on this sensor data. We have developed a system that manages a wide range of crops using LoRa technology, which is a suitable communication method for cultivating crops, and manages production volume and sales performance.

• Korean Journal of Ichthyology
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• v.7 no.2
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• pp.114-119
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• 1995

A flathead fish, collected from the water off Cheju lsland is tentatively identified as Inegocia guttata of the family Platycephalidae for the first time from Korea. Inegocia guttata is similar to Cymbacephalus beauforti in morphological characters, but differs from C. beauforti in lacking dermal flaps on eyes and having pored scales much fewer than oblique scales slanting backward and downward above the lateral line, single and tongue - like interopecular flap, nasal spines and circled blackish spots in the pectoral and ventral fins. A new Korean name, "Akoyangtae", is proposed for the I. guttata.

• Progress in Superconductivity
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• v.7 no.1
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• pp.6-10
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• 2005

We have studied feasibility of single-layer second-order $high-T_c$ SQUID gradiometers in magnetocardiography. We have measured human cardiomagnetic signals using a short-baseline (5.8 mm) single-layer second-order YBCO gradiometer in partially shielded environments. The gradiometer has an overall size of $17.6\;mm{\times}6\;mm$ and contains three parallel-connected pickup coils which are directly coupled to a step-edge junction SQUID. The gradiometer showed an unshielded gradient noise of $0.84\;pT/cm^2/Hz^{1/2}$ at 1 Hz, which corresponds to an equivalent field noise of $280\;fT/Hz^{1/2}$. The balancing factor was $10^3$. Based on the same design rules as the short-baseline devices, we have studied fabrication of 30 mm-long baseline gradiometers. The devices had an overall size of $70.2\;mm{\times}10.6\;mm$ with each pickup coil of $10\;mm{\times}10\;mm$ in outer size. As Josephson elements we made two types of submicron bridges, which are variable thickness bridge (VTB) and constant thickness bridge (CTB), from $3\;{\mu}m-wide$ and 300 nm-thick YBCO lines with a thin layer of Au on top by using a focused ion beam (FIB) patterning method. VTB was 300 nm wide, 200 nm thick, 30 nm long with Au removed and CTB 100 nm wide and 30 nm long. In temperature-dependent critical currents, $I_c(T)$, VTB showed an nonmetallic barrier-type behavior and CTB an SNS behavior. We believe that those characteristics are ascribed to naturally formed grain boundaries crossing the bridges.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.4
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• pp.355-361
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• 2018

Recently, there are efforts to improve my learning ability by using various learning tools based on ICT technology. The application such as games is used in conjunction with lecture class to induce interest in the class and to enhance the learning effect by using smartphone app as learning tool. In addition, we are trying to improve creative thinking ability, problem solving ability and logical thinking ability through early coding education. In this paper, we describe the learning and quiz app using the app inventor and conducted the related questionnaire. We developed a learning philosophy for preliminary early childhood teachers using the developed apps and taught them how to utilize them in early childhood education by explaining the apps and using the app inventor. Through questionnaires, we confirmed the learning effect and the willingness to use in early childhood education. Through this study, I hope to improve the ability of early childhood teacher learning and to utilize the coding in early childhood education with the app developed as the app inventor.