• Journal of The Korean Association For Science Education
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• v.20 no.1
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• pp.29-42
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• 2000

Hypothesis is defined as a single proposition proposed as a possible explanation for the occurrence of some observed phenomena. The purpose of this study was to analyze and categorize hypotheses generated by students on the cause of difference between the structures of muscles of the fishes and the terrestrial animals. A hypothesis-generating test was administered to 23 three college students who were majoring in science education. The study showed that college students generated manipulative and theoretical hypotheses as proposed explanations for the structural difference between muscles of the fishes and the terrestrial animals. Furthermore, students generated several hypotheses which were categorized by the quality of abductive process based on the degree of likeness between experienced knowledge and current phenomena. This study also discusses the implications of these findings for teaching and research in science education.

• Journal of Korean Elementary Science Education
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• v.30 no.2
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• pp.189-203
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• 2011

The object of this study is to investigate the views of scientifically gifted children about the purpose of scientists' experiments and school science experiments. The children's views were examined using a open-ended questionnaire survey. And then the responses from the children were analyzed with categorization. The results from the study are as follows: First, the children's views about the purpose of scientists' experiments and school science experiments were classified to 2 top-level, 5 mid-level and 21 sub-level categories. Second, it was found that the children considered internal values of doing experiments are more worthy than the social and personal usefulness of the experiments. Third, the gifted children mentioned most frequently that the purposes of the scientist experiment is 'to get the evidences for their theory and argument which is unusual in the regular children's views. Also the discovery of new phenomena and materials, and the generation of new theories and ideas were mentioned as purposes of the scientist experiments. Fourth, the students frequently stated that school science experiments support effective learning of science subject enhancing subject interests and better explanation/understanding. Fifth, relatively many students thought that the purposes of school science experiments are different with those of scientist experiments. Based on the results from the study, some educational suggestions are discussed.

• Economic and Environmental Geology
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• v.17 no.2
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• pp.109-114
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• 1984

The geophysical implications of the observed heat flow in the Korean Peninsula are examined. The Peninsula can be devided into two typical regions of high (Zone 1) and normal heat flows (Zone 2), and anomalous sharp change of heat flow between two zones is noteworthy. Zone 1 (southeastern coast of the Peninsula) to be connected to the East Sea (=Japan Sea) of high heat flow region corresponds with the region of late-Mesozoic to Tertiary igneous activity. With the radioactive elements concentrated in the crust, the observed heat flow in Zone 2 can be almostly explained. While, only a half of the heat flow in Zone 1 is explained. As a possible explanation of high heat flow in Zone 1, partial melting in the lower crust is examined. The temperature of $800-900^{\circ}C$ calculated at the bottom of the crust excludes the possibility of partial melting or magma generation in the crust. Alternatively, a remaining thermal effect of late-Mesozoic to Tertiary igneous activity is considered. However, it appears that the thermal effect already disappeared and that the vertical temperature distribution reached at steady state 30 MY ago (= 10 MY after the igneous activities came to an end). After all, the existence of some other effective heat transfer in Zone 1 is strongly suggested. The high heat flow to be same kind of anomalous one of the East Sea can be recognized as a result of the trench-back-arc thermal flux. The plate subduction in the Japan Trench will generate an induced flow above the slab of the East Sea, a typical back-arc basin, and hence the induced flow will heat the surrounding lithosphere.

• Journal of the Korea Concrete Institute
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• v.22 no.2
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• pp.171-177
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• 2010

Recently, Performance Based Design (PBD) method has been studied as a next generation structural design method, which enables a designed structure to satisfy the required performance during its service life. One method of deciding whether the required performance has been satisfied is Bayesian method, which has been commonly used in seismic analysis. Generally, it is presented as a conditional probability of exceeding some limit state (i.e., collapse) for a given ground motion. In PBD of concrete mixture design, the same methodology can be applied to assess concrete material performance based on some conditional parameters (i.e. strength, workability, carbonation, etc). In this paper, a detailed explanation of the procedure of drawing satisfaction curve by using Bayesian method based on various material parameters is shown. Also, a discussion of using the developed satisfaction curves for PBD for concrete mixture design is presented.

• Convergence Security Journal
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• v.23 no.5
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• pp.143-150
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• 2023

Applications on physically unclonable circuits (PUFs) for implementing and utilizing security protocols with hardware is on the rise. PUFs have the capability to perform functions such as authentication, prevention of replication, and secure storage of critical information in integrated circuits and security systems. Through the implementation of physically unclonable circuits, a wide range of security features, including confidentiality, integrity, and availability, can be applied. Therefore, PUFs are promising candidate to build secure integrated circuits and hardware systems. However, in order that PUFs possess security features, PUFs should possess characteristics such as unpredictability, uniqueness, and robustness characteristics. This study provides a detailed explanation and introduction of the methods to characterize the PUF properties. By applying the results, it becomes possible to quantitatively evaluate the characteristics of implemented PUFs and assess their availabilities for security system applications.

• Journal of Korean Society of Transportation
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• v.26 no.2
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• pp.81-88
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• 2008

This paper presents the travel demand estimation using interval estimation methods during the trip generation stage, and then followed the other three stages of the four stage trip estimation. We have used real data of Dae-jun City. To estimate travel demand using the interval estimation method, a reliability level was set to 95% by a upper bound value, a middle value and a lower bound value. The four stage traffic demand analysis procedure was equally applied and finally interval traffic was estimated. The result showed a difference between maximum values and middle values depending on the destination during the trip generation stage. It depends on an explanation ability of regression analysis. Most of interval estimation ratio resulted in the traffic assignment stage showed ${\pm}5{\sim}18%$ difference on the average and ${\pm}30{\sim}50%$ at the most.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8503-8512
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• 2016

The purpose of this study was to provide a detailed explanation of the mechanism of bisanthracycline, WP 631 in comparison to doxorubicin (DOX), a first generation anthracycline, currently the most widely used pharmaceutical in clinical oncology. Experiments were performed in SKOV-3 ovarian cancer cells which are otherwise resistant to standard drugs such as cis-platinum and adriamycin. As attention was focused on the ability of WP 631 to induce apoptosis, this was examined using a double staining method with Annexin V and propidium iodide probes, with measurement of the level of intracellular calcium ions and cytosolic cytochrome c. The western blotting technique was performed to confirm PARP cleavage. We also investigated the involvement of caspase activation and DNA degradation (comet assay and immunocytochemical detection of phosphorylated H2AX histones) in the development of apoptotic events. WP 631 demonstrated significantly higher effectiveness as a pro-apoptotic drug than DOX. This was evident in the higher levels of markers of apoptosis, such as the externalization of phosphatidylserine and the elevated level of cytochrome c. An extension of incubation time led to an increase in intracellular calcium levels after treatment with DOX. Lower changes in the calcium content were associated with the influence of WP 631. DOX led to the activation of all tested caspases, 8, 9 and 3, whereas WP 631 only induced an increase in caspase 8 activity after 24h of treatment and consequently led to the cleavage of PARP. The lack of active caspase 3 had no outcome on the single and double-stranded DNA breaks. The obtained results show that WP 631 was considerably more genotoxic towards the investigated cell line than DOX. This effect was especially visible after longer times of incubation. The above detailed studies indicate that WP 631 generates early apoptosis and cell death independent of caspase-3, detected at relatively late time points. The observed differences in the mechanisms of the action of WP631 and DOX suggest that this bisanthracycline can be an effective alternative in ovarian cancer treatment.

• Journal of Korean Medical classics
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• v.31 no.4
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• pp.79-90
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• 2018

Objectives : In present, various definitions of Zhongshu are being used interchangeably in Korea. The paper attempted to discover the disease of Zhongshu as studied by Lidongyuan, who was ahead of his time. Methods : A database of medical books has been studied to find Lidongyuan's writings on the disease of Zhongshu, and mentions about Li's works in past medical books. The paper contemplated the subject by defining the disease of Zhongshu and reviewing the disputes related to the subject. Results & Conclusions : Lidongyuan gave a detailed explanation on the fact that Zhangjiegu distinguished between Zhongshu and Zhongre, and this was influenced by Shangshu as mentioned in Taipinghuiminhejijufang. Therefore, it can be deduced that he was aware of the fact that summerheat-heat as latent summer heat syndrome is lurking inside the body, not being able to be released. According to the disease of Zhongshu by Lidongyuan, yin cold was receieved secondary after first receiving summerheat-heat. It is either summerheat damaged defensive qi, failure in storing the essence made defensive qi weak, or seasonal reasons have caused the defensive qi to be drained and leave the body exposed to damage by summerheat. This is because the fundamental main cause is the hitting of summerheat, since yin cold was received after the presence of summerheat-heat is made first. Many doctors in the following generation criticized that Lidongyuan's disease of Zhongshu cannot be named as a Zhongshu due to its similarity with Shanghan. However, they cannot be viewed as similar since it is a phenomenon where yin cold becomes congested while the body is weak and heat is generated in the body due to summerheat-heat. The doctors who said they were similar only focused on the external cause that was only the superficial issue. According to Lidongyuan's method, the right way to treat a Zhongshu disease is to use the method of tonifying the qi and eliminating the heat in conjunction with eliminating the internal dampness or treat the external syndrome, or to use a formula to tonify the qi and eliminate the fire heat before eliminating the internal dampness or treating the external syndrome.

• Korean Journal of Clinical Laboratory Science
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• v.49 no.4
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• pp.323-328
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• 2017

Angiogenesis is a process including members of the angiogenic factors. In particular, fibroblast growth factor 2 (FGF2) is considered the most potent angiogenic factor because it promotes cell proliferation and tube formation. A recent study reported that fucoidan derived from marine plant potentiated FGF-2 induced tube formation in human endothelial cells. On the other hand, the molecular mechanisms involved in the angiogenic activity of fucoidan and FGF2 are unknown. In this study, a fucoidan treatment promoted angiogenesis induced by FGF2. The effects of fucoidan on FGF2-induced angiogenesis were confirmed by a proliferation assay using a CellTiter96 Aqueous One solution after a treatment with fucoidan and FGF2. The tube formation and wound healing assay for the angiogenic activity were also confirmed. Reverse transcription PCR showed a change in the mRNA of vascular endothelial growth factor-A (VEGF-A), intercellular adhesion molecule-1 (ICAM-1), matrix metallopeptidase9 (MMP9), and the signal transducer and activator of transcription3 (STAT3). In summary, the Fucoidan/FGF2 treatment induced an increase in cell proliferation, improved the tube formation and wound healing activity, and altered the STAT3, VEGF-A, ICAM-1, and MMP9 mRNA expression levels. Further research will be needed to provide a scientific explanation in terms of cell-signaling and confirm the present findings.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.241-241
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• 2008

Macrofore formation in silicon and other semiconductors using electrochemical etching processes has been, in the last years, a subject of great attention of both theory and practice. Its first reason of concern is new areas of macropore silicone applications arising from microelectromechanical systems processing (MEMS), membrane techniques, solar cells, sensors, photonic crystals, and new technologies like a silicon-on-nothing (SON) technology. Its formation mechanism with a rich variety of controllable microstructures and their many potential applications have been studied extensively recently. Porous silicon is formed by anodic etching of crystalline silicon in hydrofluoric acid. During the etching process holes are required to enable the dissolution of the silicon anode. For p-type silicon, holes are the majority charge carriers, therefore porous silicon can be formed under the action of a positive bias on the silicon anode. For n-type silicon, holes to dissolve silicon is supplied by illuminating n-type silicon with above-band-gap light which allows sufficient generation of holes. To make a desired three-dimensional nano- or micro-structures, pre-structuring the masked surface in KOH solution to form a periodic array of etch pits before electrochemical etching. Due to enhanced electric field, the holes are efficiently collected at the pore tips for etching. The depletion of holes in the space charge region prevents silicon dissolution at the sidewalls, enabling anisotropic etching for the trenches. This is correct theoretical explanation for n-type Si etching. However, there are a few experimental repors in p-type silicon, while a number of theoretical models have been worked out to explain experimental dependence observed. To perform ordered macrofore formaion for p-type silicon, various kinds of mask patterns to make initial KOH etch pits were used. In order to understand the roles played by the kinds of etching solution in the formation of pillar arrays, we have undertaken a systematic study of the solvent effects in mixtures of HF, N-dimethylformamide (DMF), iso-propanol, and mixtures of HF with water on the macrofore structure formation on monocrystalline p-type silicon with a resistivity varying between 10 ~ 0.01 $\Omega$ cm. The etching solution including the iso-propanol produced a best three dimensional pillar structures. The experimental results are discussed on the base of Lehmann's comprehensive model based on SCR width.