• Atmosphere
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• v.16 no.1
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• pp.19-31
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• 2006

The purpose of this study is to develop the statistical model to predict sea level pressure of typhoon period in south coast of the Korean Peninsula. Seven typhoons, which struck south coast of the Korean Peninsula, are selected for this study, and the data for analysis include the central pressure and location of typhoon, and sea level pressure and location of 19 observing site. Models employed in this study are the first order regression, the second order regression and the neural network. The dependent variable of each model is a 3-hr interval sea level pressure at each station. The cause variables are the central pressure of typhoon, distance between typhoon center and observing site, and sea level pressure of 3 hrs before, whereas the indicative variable reveals whether it is before or after typhoon passing. The data are classified into two groups - one is the full data obtained during typhoon period and the other is the data that sea level pressure is less than 1000 hPa. The stepwise selection method is used in the regression model while the node number is selected in the neural network by the Schwarz's Bayesian Criterion. The performance of each model is compared in terms of the root-mean square error. It turns out that the neural network shows better performance than other models, and the case using the full data produces similar or better results than the case using the other data.

• Journal of The Korean Association For Science Education
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• v.16 no.1
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• pp.61-76
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• 1996

The purpose of this study was to apply the instructional strategies for conceptual change prescribed by Posner et al(1982) to the astronomic content domain taught in the elementary and middle school and to analyze the characteristics of students' knowledge revealed in the test before, during and after the instruction. Also, it was to investigate the intercorrelation of cognitive levels, spatial ability and science achievement. The major findings of this study are as follows: 1. Students had a great variety of misconceptions related to the motion of the moon before the instruction, that is, the phases, the names of phases and the cause of changing phases by the moon's orbit about the earth, the moon's appearance and location at the given time, the relative positions of earth, moon and sun during a lunar eclipse, the cause that a full moon is not at the line of node once a month. In the analysis of students' responses concerning the cause of changing phases of the moon and a lunar eclipse, the results indicate that the great majority of students had rote learning rather than meaningful learning in the middle school. 2. Students' reponses during the instruction concerning the changing phases of the moon and the predictive knowledge about the motions of the earth and the moon were analyzed. 1) According to the results of the test given before and after experiment, after discussion, achievement score of the whole of subjects and groups in both preformal and formal cognitive levels appeared to increase linearly. 2) There was no statistically significant differences of achievement scores before and after experiment, after discussion between preformal group and formal group in cognitive levels. 3. Distribution of achievement scores according to the whole of subjects and groups in preformal and formal cognitive levels shows that there was a statistically significant difference between pretest and posttest. 4. Types of conceptual changes concerning the cause of changing phases of the moon that occurred from pretest to posttest were classified as accommodation, incomplete accommodation, assimilation, no change and no model. Six of the seven students starting instruction with alternative frameworks didn't sustain those alternative models throughout instruction. Five of these six students accommodated completely and the last one partially. Seventy-nine percentage of students taking instruction with fragmental models assimilated correct propositions at the end of the instruction. These results suggest that conceptual change model prescribed by Posner et al(1982) has promised the meaningful learning to students taking with fragmental models, especially in cases where students with misconception enter instruction. 5. High correlation between achievement score of simple-recall items and that of written items in pretest and posttest indicates that the higher students got the score in simple-recall items the better they also performed in written items. However, there was no statistically significant differences among cognitive levels, spatial ability and science achievement in the whole of subjects and groups according to the cognitive levels.

• Animal cells and systems
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• v.1 no.1
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• pp.157-164
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• 1997

Ly-6E.1 antigen was proposed as a regulatory molecule of T lymphocyte activation, a hematopoietic stem cell marker, a memory cell marker, and an adhesion molecule. Though there were several reports suggesting the presence of Ly-6 ligand, the characterization of the ligand was not yet performed, As an attempt to screen the expression of Ly-6E.1 ligand, we prepared a probe for detecting Ly-6E.1 ligand by producing a fusion protein between Ly-6E.1 and $hlgC_{r1}$, A mammalian cell expression vector with Ly-6E.$1/hlgC_{r1}$ chimeric cDNA was transfected in SP2/0-Ag14 myeloma cells, and stable transfectants were selected. The fusion protein was produced as a dimer and maintained the epitopes for monoclonal antibodies specific for Ly-6E.1 and for anti-human lgG antibody. The purified fusion protein through Gammabind G column was used for FACS analyses for the expression of Ly-6E.1 ligand. The fusion protein interacted with several cell lines originating from B cells, T cells, or monocytes. The fusion Protein also strongly stained bone marrow, lymph node, and spleen cells, but thymic cells weakly, if any. The staining was more obvious in C57BL/6 $(Ly-6^b)$ than Balb/c $(Ly-6^a)$ mice. These results suggest that the interaction of Ly-6E.1 with Ly-6E.1 ligand may function both in the stem cell environment and in the activation of mature lymphocytes. The fusion protein may be a valuable tool in characterization of biochemical properties of the Ly-6E.1 ligand and, further, in isolating its cDNA.

• The Journal of Society for e-Business Studies
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• v.21 no.3
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• pp.79-99
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• 2016

Supply network of automobile part is addressed with the e-invoices generated at real time. Automobile is composed of 8 modules. Firms which produce these modules are defined as the first outsourcing firm. Brake is the part of power control module and so, brake manufacturing firm is called the second outsourcing firm. In this paper, the third supply networks of brake manufacturing firms is analyzed with e-invoices and social network method. At the node-level, the third outsourcing firms are classified into 3 categories, interator, allocator and hub with respect to their role at the ego-network of each brake manufacturing firm. At the network level, A2, one of 3 brake manufacturing firms have more outsourcing firms and bigger centrality than the other brake manufacturing firms. Intre-firms trade patterns are, also, analyzed by using the degree of trade dedication with respect to the modes of business. It is shown that trade pattern of retail, commodity brokerage firm, rubber and plastic manufacturing firm are hierarchical trade because their degree of trade dedication is almost near to 1.

• Journal of the Korea Society of Computer and Information
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• v.15 no.4
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• pp.83-90
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• 2010

In wireless sensor networks, the data transmitted from the sensor nodes are susceptible to corruption by errors which caused of noisy channels and other factors. In view of the severe energy constraint in Sensor Networks, it is important to use the error control scheme of the energy efficiently. In this paper, we presented RS (Reed-Solomon) codes in terms of their BER performance and power consumption. RS codes work by adding extra redundancy to the data. The encoded data can be stored or transmitted. It could have errors introduced, when the encoded data is recovered. The added redundancy allows a decoder to detect which parts of the received data is corrupted, and corrects them. The number of errors which are able to be corrected by RS code can determine by added redundancy. The results of experiment validate the performance of proposed method to provide high degree of reliability in low-power communication. We could predict the lifetime of RS codes which transmitted at 32 byte a 1 minutes. RS(15, 13), RS(31, 27), RS(63, 57), RS(127,115), and RS(255,239) can keep the days of 173.7, 169.1, 163.9, 150.7, and 149.7 respectively. The evaluation based on packet reception ratio (PRR) indicates that the RS(255,239) extends a sensor node's communication range by up about 3 miters.

• Radiation Oncology Journal
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• v.12 no.3
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• pp.323-329
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• 1994

Purpose: In supraglottic cancer, radiation therapy is used to preserve the laryngeal function but combined surgery and radiation therapy is required in advanced stage. The authors Present the results of radiation therapy alone and combined surgery Plus Postoperative radiation therapy for supraglottic cancer. Methods and Materials: A retrospective analysis was done for 43 patients with squamous cell carcinoma of the supraglottic larynx who were treated from Feburary 1982 to December 1991, in the Department of Radiation Oncology, Korea University Hospital. Patient distribution according to the AJCC staging system was as follows: I, 3($7.0\%$); II, 7($16.3\%$); III, 17($39.5\%$); IV, 16($37.2\%$). Patients' age ranged from 30 to 72 years(median 62). Follow up durations were from 21 to 137 months(median 27). Seventeen patients($39.5\%$) were treated by radiation therapy alone with radiation doses of 6840-7380 cGy and 26 patients($60.5\%$) were treated with surgery plus postoperative irradiation with doses of 5820-6660 cGy. Results: Overall five-year survival rate for all stage was $51.8\%$, with $100\%$ for Stage I and II, $47.3\%$ for Stage III, and $29.2\%$ for Stage III. The difference of the survival rate by stage was statistically significant(p=0.0152). Five-year survival rates were $100\%$ for locally confined tumor in the supraglottic larynx, $37.5\%$ for transglottic extension, $26.7\%$ for hypopharynx extension, and only two of 5 patients with both transglottic and hypopharynx extension were alive(p=0.0033). Five-year survival rates by neck node status were as follows: $55.0\%$ for NO, $64.3\%$ for N1, $50.0\%$ for N2, and all 2 of N3 were died of disease. Overall survival rate for radiation therapy alone group was $42.8\%$, and it was $56.7\%$ for surgery plus postoperative radiation therapy group with no statistically significant difference(p=0.5215). In Stage I and II, all Patients survived. In Stage III and IV, 5-year survival rate for radiation therapy alone group was $28.5\%$ and $43.4\%$ for surgery plus postoperative irradiation group(p=0.5103). Local control rate was $58.8\%$(10/17) for radiation therapy alone group and $73.1\%$ (19/26) for surgery plus postoperative irradiation group. Three patients from surgery plus postoperative radiation therapy group developed distant metastasis in lungs. Conclusion: Treatment results of radiation therapy alone was excellent in early stage supraglottic cancer. In advanced stage, even the difference was statistically not significant, the result of postoperative radiation therapy group was superior compared with radiation therapy alone group. Since 1992, concomitant chemoradiotherapy with hyperfractionated radiotherapy is being used to improve the result of the treatment and preserve the laryngeal function in advanced stage supraglottic cancer.

• The Journal of Korean Medicine
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• v.28 no.1 s.69
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• pp.105-116
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• 2007

Objectives : Mahuang (Ephedra sinica), well known as an herbal medicine in the East and West, contains a relatively high percentage of ephedrine known as sympathomimetic alkaloid. We investigated the effects of Mahuang on sympathetic nervous system with heart rate variety (HRV). Time and frequency domain analysis of HRV is a noninvasive technique capable of providing information on autonomic modulation of the sinus node. Methods : We investigated 57 healthy volunteers consisting of 37 subjects in the Mahuang group and 20 subjects in the placebo group. Study form was a randomized, placebo-controlled, double-blind clinical trial. The 37 subjects in the Mahuang group took 3 Mahuang capsules (1 capsule equivalent to 2g herb Mahuang) twice a day at 10 a.m. and 2 p.,., while the 20 subjects in the placebo group took 3 placebo-capsules filled with glutinous rice powder at the same times. Mahuang medicine and placebo medicine were made into opaque capsules. We measured HRV at 3 p.m. 1 or 2 days before medication and at 3 p.m. after medication. Results : Mean-RR and SDNN of the Mahuang group significantly decreased compared with that of the placebo group, but the heart rate of the Mahuang group significantly increased compared with the placebo. HRV-Index, RMSSD and SDSD of the Mahuang group significantly decreased compared with that of the placebo group, but PNN50 of the Mahuang group significantly increased compared with placebo. Ln(TP), Ln(VLF), Ln(LF) and Ln(HF) of the Mahuang group significantly decreased compared with those of the placebo group. There were no significant differences in normalized LF, normalized HF and LF/HF ratio between the Mahuang and placebo groups. Conclusion : The results suggest that Mahuang in healthy adults tends to reduce the autonomic nervous system within the normal range.

• Journal of Biomedical Engineering Research
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• v.18 no.4
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• pp.429-438
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• 1997

Mechanical valve is one of the most widely used implantable artificial organs of which the reliability is so important that its failure means the death of patient. Therefore early noninvasive detection is essentially required, though mechanical valve failure with thrombosis is the most common. The objective of this paper is to detect the thrombosis formation by spectral analysis and neural network. Using microphone and amplifier, we measured the sound from the mechanical valve which is attached to the pneumatic ventricular assist device. The sound was sampled by A/D converter(DaqBook 100) and the periodogram is the main algorithm for obtaining spectrum. We made the thrombosis models using pellethane and silicon and they are thrombosis model on the valvular disk, around the sewing ring and fibrous tissue growth across the orifice of valve. The performance of the measurment system was tested firstly using 1 KHz sinusoidal wave. The measurement system detected well 1KHz spectrum as expected. The spectrum of normal and 5 kinds of thrombotic valve were obtained and primary and secondary peak appeared in each spectrum waveform. We find that the secondary peak changes according to the thrombosis model. So to distinguish the secondary peak of normal and thrombotic valve quantatively, 3 layer back propagation neural network, which contains 7, 000 input node, 20 hidden layer and 1 output was employed The trained neural network can distinguish normal and valve with more than 90% probability. As a conclusion, the noninvasive monitoring of implanted mechanical valve is possible by analysing the acoustical spectrum using neural network algorithm and this method will be applied to the performance evaluation of other implantable artificial organs.

• Journal of Gastric Cancer
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• v.17 no.3
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• pp.228-236
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• 2017

Purpose: Enolase is a cytoplasmic enzyme that catalyzes the conversion of 2-phosphoglycerate to phosphoenolpyruvate in the glycolytic pathway. The aim of this study was to investigate whether the overexpression of neuron-specific enolase (NSE) can serve as a prognostic factor in patients with gastric cancer (GC). Materials and Methods: To assess its prognostic value in GC, NSE expression was measured by immunohistochemistry in a clinically annotated tissue microarray comprising of 327 human GC specimens. Cytoplasmic NSE expression was scored from 0 to 4, reflecting the percentage of NSE-positive cells. Results: In terms of histology as per the World Health Organization criteria (P=0.34), there were no differences between the NSE overexpression (NSE-OE) and NSE underexpression (NSE-UE) groups. The NSE-OE group showed a significantly lower rate of advanced GC (P<0.01), lymph node metastasis (P=0.01), advanced stage group (P<0.01), cancer-related death (P<0.01), and cancer recurrence (P<0.01). Additionally, a Kaplan-Meier survival analysis revealed that the NSE-OE group had longer cumulative survival times than the NSE-UE group (log-rank test, P<0.01). However, there were no significant differences in the serum levels of NSE expression in patients with GC and healthy volunteers (P=0.28). Conclusions: Patients with NSE overexpressing GC tissues showed better prognostic results, implying that NSE could be a candidate biomarker of GC.

• The Transactions of the Korea Information Processing Society
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• v.4 no.3
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• pp.831-845
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• 1997

In this paper,we proposed and developed a compiler and interactive programming enviroments for C++ wich is mostly worth of nitice among the object -oriented languages.To develope the compiler for C++ we took front=end/back-end model using EM virtual machine.In develpoing Front-End,we formailized C++ gram-mar with the context semsitive tokens which must be manipulated by dexical scanner and designed a AST class li-brary which is the hierarchy of AST node class and well defined interface among them,In develpoing Bacik-End,we proposed model for three major components :code oprtimizer,code generator and run-time enviroments.We emphasized the retargatable back-end which can be systrmatically reconfigured to genrate code for a variety of distinct target computers.We also developed terr pattern matching algorithm and implemented target code gen-erator which produce SPARC code.We also proposed the theroy and model for construction interative pro-gramming enviroments. To represent language features we adopt AST as internal reprsentation and propose uncremental analysis algorithm and viseal digrams.We also studied unparsing scheme, visual diagram,graphical user interface to generate interactive environments automatically Results of our resarch will be very useful for developing a complier and programming environments, and also can be used in compilers for parallel and distributed enviroments.