• Korean Journal of Ecology and Environment
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• v.42 no.1
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• pp.48-57
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• 2009

Primary production of epiphytic and planktonic algae in a shallow reed zone of a lagoon Nishinoko was investigated. Concentrations of nutrients varied widely horizontally and locally in the lagoon. It seems that the reed zone has a heterogeneous environment. The photosynthetic rates of epiphytic and planktonic algae were 7 to 14 mg C surface stem $m^{-2}hr^{-1}$ and 12 to $46mg\;Cm^{-3}hr^{-1}$, respectively. The areal primary production of epiphytic algae was estimated as 4 to $13mg\;Cm^{-2}hr^{-1}$ from the stem density of Phragmites and the water depth at each station. The production of phytoplankton, on the other hand, was 5 to $56mg\;Cm^{-2}hr^{-1}$. The contribution of epiphytic algae to total primary production averaged 53%, although the assimilation number was much lower than that of phytoplankton. The present results indicate that the epiphytic algae are one of the significant primary producers in the reed zone.

• Journal of Engineering Education Research
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• v.21 no.2
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• pp.17-27
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• 2018

This study aims to investigate the effect of design thinking-based STEAM program for primary and secondary students. The design thinking-based STEAM program dealt with advanced scientific technology issues and it consisted of 8 topics. A questionnaire was developed to explore the change of Science concept awareness, Interest, Self-efficacy, Career consciousness of students through the program. The questionnaire consisted of following 4 areas, such as 'Science concept awareness', 'Interest', 'Career consciousness' and 'Self efficacy'. Pre-post test was conducted to 75 primary and secondary students. As a result of analyzing post-test compared to pre-test, 'Science concept awareness', 'Career consciousness' and 'Self efficacy' of students were improved. And the 'Interest' wasn't changed significantly. Through this research, it can be suggested that the design thinking-based STEAM program can be useful at school education to improve the Science concept awareness, Career consciousness and Self-efficacy of primary and secondary students. It is also proposed that further research of the various areas of interest and other affective variables will be needed.

• Mass Spectrometry Letters
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• v.14 no.4
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• pp.147-152
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• 2023

The increasing demand for two-dimensional imaging analysis using optical or electronic microscopic techniques has led to an increase in the use of simple one-dimensional and two-dimensional mass spectrometry imaging. Among these imaging methods, secondary-ion mass spectrometry (SIMS) has the best spatial resolution using a primary ion beam with a relatively insignificant beam diameter. Until recently, SIMS, which uses high-energy primary ion beams, has not been used to analyze molecules. However, owing to the development of cluster ion beams, it has been actively used to analyze various organic molecules from the surface. Researchers and commercial SIMS companies are developing cluster ion beams to analyze biological samples, including amino acids, peptides, and proteins. In this study, a water droplet ion beam for surface analysis was realized. Water droplets ions were generated via electrospraying in a vacuum without desolvation. The generated ions were accelerated at an energy of 10 keV and collided with the target sample, and secondary ion mass spectra were obtained for the generated ions using ToF-SIMS. Thus, the proposed water droplet ion-beam device showed potential applicability as a primary ion beam in SIMS.

• Journal of Korean Neurosurgical Society
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• v.53 no.4
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• pp.228-234
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• 2013

Objective : We have limited understanding on the presentation and survival of primary spinal sarcomas. The survival, recurrence rate, and related prognostic factors were investigated after treatment for primary sarcomas of the spine. Methods : Retrospective analysis of medical records and radiological data was done for 29 patients in whom treatment was performed due to primary sarcoma of the spine from 2000 to 2010. As for treatment method, non-radical operation, radiation therapy, and chemotherapy were simultaneously or sequentially combined. Overall survival (OS), progression free survival (PFS), ambulatory function, and pain status were analyzed. In addition, factors affecting survival and recurrence were analyzed : age (${\leq}42$ or ${\geq}43$), gender, tumor histologic type, lesion location (mobile spine or rigid spine), weakness at diagnosis, pain at diagnosis, ambulation at diagnosis, initial treatment, radiation therapy, kind of irradiation, surgery, chemotherapy and distant metastasis. Results : Median OS was 60 months, the recurrence rate was 79.3% and median PFS was 26 months. Patients with distant metastasis showed significantly shorter survival than those without metastasis. No factors were found to be significant relating to recurrence. Prognostic factor associated with walking ability was the presence of weakness at diagnosis. Conclusion : Primary spinal sarcomas are difficult to cure and show high recurrence rate. However, the development of new treatment methods is improving survival.

• Journal of electromagnetic engineering and science
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• v.11 no.2
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• pp.128-132
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• 2011

In interference tolerance based spectrum sharing systems, primary receivers (PRs) are protected by a predefined peak or average interference power constraint. To implement such systems, cognitive radio (CR) transmitters are required to adjust their transmit power so that the interference power received at the PR receivers is kept below the threshold value. Hence, a CR-transmitter requires knowledge of its channel and the primary receiver in order to allocate the transmit power. In practice, it is impossible or very difficult for a CR transmitter to have perfect knowledge of this channel state information (CSI). In this paper, we investigate the impact of imperfect knowledge of this CSI on the performances of both a primary and cognitive radio network. For fixed transmit power, average interference power (AIP) constraint can be maintained through knowledge of the channel distribution information. To maintain the peak interference power (PIP) constraint, on the other hand, the CR-transmitter requires the instantaneous CSI of its channel with the primary receiver. First, we show that, compared to the PIP constraint with perfect CSI, the AIP constraint is advantageous for primary users but not for CR users. Then, we consider a PIP constraint with imperfect CSI at the CR-transmitter. We show that inaccuracy in CSI reduces the interference at the PR-receivers that is caused by the CR-transmitter. Consequently the proposed schemes improve the capacity of the primary links. Contrarily, the capacities of the CR links significantly degrade due to the inaccuracy in CSI.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.23 no.1
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• pp.21-25
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• 1978

Primary triticale was newly established by colchicine treatment of intergeneric hybrid F 1 plants crossed between T. aestivum var. Jugoku #81 and S. cereale var. Jaelae. The agronomic and cytological characteristics were studied.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.1
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• pp.98-106
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• 2007

Statement of problem: Current tendencies of the implant macrodesign are tapered shapes for improved primary stability, but there are lack of studies regarding the relationship between the implant macrodesign and primary stability. Purpose: The purpose is to investigate the effect of implant macrodesign on the implant primary stability by way of resonance frequency analysis in the bovine rib bones with different kinds of quality. Material and method: Fifty implants of 6 different kinds from two Korean implant systems were used for the test. Bovine rib bones were cut into one hundred pieces with the length of 5 cm. Among them forty pieces of rib bones with similar qualities were again selected. For the experimental group 1, the thickness of cortical part was measured and 20 pieces of rib bones with the mean thickness of 1.0mm were selected for implant placement. For the experimental group 2, the cortical parts of the remaining 20 pieces of rib bones were totally removed and then implants were placed on the pure cancellous bone according to the surgical manual. After placement of all implants, the implant stability quotient(ISQ) was measured by three times, and its statistical analysis was done. Results: There are statistically significant differences in ISQ values among 4 different kinds of Avana system implants in the experimental group 2. For the experimental group 1, Avana system implants showed significantly different ISQ values, but when differences in the thickness of cortical parts were statistically considered, did not show any significant differences in ISQ values. Among Oneplant system implants, there are no significant differences in ISQ values for the experimental group 2 as well as for the experimental group 1. Conclusion: Within the limits of this study, bone quality and implant design have some influences on the primary stability of implants. Especially in the bone of poor quality, tapered shape of implants are more favorable for the primary stability of implants.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.297-303
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• 2006

Cuticular waxes on tea (Camellia sinensis L.) loaves consisted mainly of alkanes, fatty acids, primary alcohols, triterpenes, and a group of unknown compounds, dominated by primary alcohols and triterpenes. Tea tree accessions used in this study were M-1, M-2, Sakimidori, and Yabukita. For all accessions, the alkane, fatty acid, and primary alcohol constituents consisted of a homologues series, and the major constituents of primary alcohol class were the C28 and C30 homologues. Triterpenes consisted of friedelin, $\beta-amyrin$, and three unidentified ones and friedelin was the most abundant. Leaf area and the total amounts of cuticular waxes per leaf increased with lower leaf position from the apical bud in Yabukita variety. With different leaf position, total wax amount per unit leaf area on the youngest leaves of P1 (the uppermost leaf position) showed the largest amount $(12.80{\mu}g/cm^2)$, and on mature loaves of P2 to P6 ranged from 7.08 to $7.77{\mu}g/cm^2$, and then on the oldest loaves of P7 (the lowest leaf position) remained at an increased level $(17.53{\mu}g/cm^2)$. During leaf development (lower leaf position), the amount of primary alcohols decreased from P1 to P6 and increased at P7, whereas that of triterpenes increased from P1 to P7. The percentage of each wax class in the total wax amount occurred a decrease in primary alcohol and an increase in triterpene, with leaf age.

• Preventive Nutrition and Food Science
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• v.12 no.4
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• pp.242-250
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• 2007

This study evaluated the storage stability of a variety of sauce products in the Korean market, determined primary quality indices for three typical products, and proposed functional relationships that are useful for determining shelf life at different temperatures. Most of the products examined were found to combine hurdles of low pH, low water activity, and the use of heat processing as methods for producing the required storage stability while maintaining the sensory quality of the products. For a meat extract solution produced for cold noodles (pH=4.3; $a_w=0.98$), the primary quality change determining shelf life was lipid oxidation, determined here by the TBA value. The primary quality index of a soybean paste seasoning mix (pH=4.0; $a_w=0.78$), which had a microbial load of 2.8 log (CFU/g), was a decrease in its pH. The primary quality index for a sandwich spread (pH=4.0; $a_w=0.88$) was changes in its surface color. The temperature dependence of changes in the primary quality indices can be described by the Arrhenius equation, which can estimate the shelf life at any arbitrary limit as a function of temperature. The activation energies for changes in the primary quality indices of the meat extract solution, the soybean paste seasoning, and the sandwich spread were 20.3, 27.2, and 43.5 kJ/mol, respectively.

• Parasites, Hosts and Diseases
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• v.39 no.4
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• pp.327-328
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• 2001

A survey of the infection rate of Enterobius vermicularis among students in 4 primary schools located in Gangwon-do (Province) was done from May to .Tune 2001. Among the 398 examinees,39 (9.8%) were infected with E. vermicularis demonstrated by the adhesive cellotape anal swab method. The infection rates ranged from 8.3% to 11.8% among the four schools. The infection rate of males and females was 10.7% and 7.7% respectively. The first grade students showed the highest infection rate, 28.7%. The confirmed cases were treated with albendazole three times at an interval of 15 days. We were able to confirm that E. vermicularis infection is still prevalent among students in Gangwon-do , Korea.