• Journal of The Korean Association For Science Education
• /
• v.26 no.2
• /
• pp.258-267
• /
• 2006

The purpose of this study was to investigate the practical use of process skill under the seventh curriculum at secondary school and teachers' perceptions about hypothesis. Two hundred and twenty-two secondary science teachers responded to a survey. Among all process skills, data interpretation was found to be used most frequently by science teachers. The second most-commonly utilized skill was conclusion, and the least employed skill was hypothesis formation followed closely by data transformation. In addition to these results, the most difficult process skill practised by science teachers was hypothesis formation, followed by data transformation, and controling variables. A majority of science teachers (63.1%) properly defined hypothesis, but only a significant number (5.0%) chose the correct example about hypothesis in real-world contexts. More than ninety percent of science teachers believed the skill of hypothesis formation could be put to use in junior high to senior high school, but practical use of the skill, was too difficult for the science class

• Journal of the Korean Regional Science Association
• /
• v.40 no.2
• /
• pp.57-73
• /
• 2024

The purpose of this study is to establish the central hierarchy and urban spatial structure of Daejeon in 2040 using differentiated analysis indicators. In order to establish a central hierarchy in the future urban space of Daejeon City, three indicators were derived: population density, use of buildings (commercial, office, residential, etc.) and traffic volume data(KTDB). The results of analyzing the center hierarchy using indicators are as follows. First, the primary centers responsible for urban (core) functions are set in three areas, including Dunsan downtown, the original downtown (Daejeon Station area, designated as a special urban convergence zone), and Doan New Town, and the secondary centers corresponding to sub-city centers (regional bases). was set at 9, 10 tertiary centers corresponding to regional centers (living area centers), and a center hierarchy was established with 5 new specialized bases. Second, new secondary and tertiary centers emerged that were different from the center hierarchy in the 2030 Daejeon Urban Basic Plan. The three indicators used in this study yielded meaningful results in establishing urban spatial structure and central hierarchy that can secure urban competitiveness.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.26 no.1
• /
• pp.42-46
• /
• 2022

Purpose In the meantime, there have been not many samples that require dilution, and it has been difficult for the examiner to set an appropriate dilution multiple for RIA test item and report the results. Accordingly, it was judged that it was necessary to set the maximum dilution multiple for each test and to verify the upper limit of the clinical reportable range. Therefore, in this study, the maximum dilution multiple for each RIA test was set and the upper limit of the clinical reportable range was verified accordingly Materials and Methods Among all RIA tests conducted at Asan Medical Center, the study treated on 30 types of tests which also conduct the dilution test. Data from March to July 2021 were collected and analyzed. The study was conducted on samples subjected to serial dilutions such as X2, X4 or X10, X10², X10³, X10⁴, X10⁵. Results Among a total of 30 test types, 18 test types have more than 5 N values in the tolerance range of 80~120%. As a result of the verification of maximum dilution multiples, the test set to 10⁴ is 𝛼-fetoprotein and thyroglobulin, and the test set to 10³ is CA-125, CEA, and 𝛽-hCG, and the test set to 10² is Free PSA, PSA, CA15-3, SCC, Ferritin, PTH, Cortisol, and Calcitonin. Tests set to 10 include three categories: 𝛽2-Microglobulin, C-peptide, and Testosterone. Conclusion It is expected that it will contribute to improving the quality of nuclear medicine blood tests as the results of dilution experiments can be reported quickly and accurately through the verification of the clinical reportable range.

• 종축개량
• /
• v.13 no.2
• /
• pp.3-6
• /
• 1991

• Journal of Korea Fair Competition Federation
• /
• no.27
• /
• pp.48-50
• /
• 1997

• Phonetics and Speech Sciences
• /
• v.11 no.4
• /
• pp.97-108
• /
• 2019

An automated Praat script was implemented to measure optimal formant frequencies for adults. Optimal formant analysis could be interpreted to show that the deviation of formant frequency that resulted from the two variously combined setting parameters (maximum formant and number of formants) was minimal. To increase the reliability of formant analysis, LPC order should be set differently, based on the gender or vowel type. Praat recommends 5,000 Hz and 5,500 Hz as maximum formant settings and, at the same time, recommends 5 as the number of formants for males and females. However, verification is needed to determine whether these recommended settings are valid for Korean vowels. Statistical analysis showed that formant frequencies significantly varied across the adapted scripts, especially with respect to the data on females. Formant plots and statistical results showed that linear_script and qtone_script are much more reliable in formant measurements. Among four kinds of scripts, the linear and qtone_scripts proved to be more stable and reliable. While the linear_script was designed to have a linearly increased formant step in for-loop, the increment of formant step in the qtone_script was arranged by quarter tone scale (base frequency×common ratio ($\sqrt[24]{2}$)). When looking at the tendency of the formant setting drawn by the two referred algorithms in the context of front vowel [i, e], the maximum formant was set higher; and the number of formants set at a lower value than recommended by Praat. The back vowel [o, u], on the contrary, has a lower maximum formant and a higher number of formants than the standard setting.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.20 no.3
• /
• pp.103-110
• /
• 2016

Recently, structural health monitoring system(SHMS) has been appled cable bridges as the effective maintenance tool and the management threshold is considered to assess the status of the bridge in SHMS. The threshold is generally determined by the allowable limit based on design specification because there is no method and standard for threshold calculation. In case of the conventional thresholds, it is difficult to recognize the event, abnormal behavior and gradual damage within the threshold. Therefore, this study reviewed the problem of previous methods and proposed the advanced methodologies based on probabilistic approach for threshold calculation which can be applied to practice work. Gumbel distribution is adopted in order to calculate the threshold for caution and warning states considering the expectations for return periods of 50 and 100 years. The thresholds were individually determined for measurement data and data variation to detect the various abnormal behaviors within allowable range. Finally, it has confirmed that the thresholds by the proposed method is detectable the abnormal behavior of real-time measuring data from SHMS.

• Journal of Korean Society for Geospatial Information Science
• /
• v.1 no.2 s.2
• /
• pp.195-206
• /
• 1993

As the first step in developing the urban information system it is very important to identify the location of the street, and the feature of objects on it Also it is necessary to understand the relationship between objects concerned. In order to manage these information efficiently, the road information should be well organized and standardized for digital data. Because the road is the base place under which most urban utilities are buried. However, the present real situation is that even if we have unique numbers authorized by law for some parts of the road it is too ambiguous to figure out the spatial location of the specific area because the assigned area is so large and incoherent. Therefore, the purpose of this study is to propose a road location identication scheme, to apply this scheme at Kangnam-ku Seoul, and finally to propose the guideline in developing the road management information system in Korea. The road identification scheme developed in this study are as follows: (1) The road is defined as a fixed factor, and was given the identification number which repressents the funtion, relationship, and direction of the road without the road section and absolute coordinates. (2) The parcel identification nutter was given to each route to understand it possible to understand the location of the road itself and surroundings. (3) To update the md information using the scheme developed in this study relative coordinate method(Dynamic Segmentation) based on the road centerline was applied.

• Journal of the Korea Society for Simulation
• /
• v.20 no.3
• /
• pp.69-78
• /
• 2011

A large-scale sensor network usually operates in open and unattended environments, hence individual sensor node is vulnerable to various attacks. Therefore, malicious attackers can physically capture sensor nodes and inject false reports into the network easily through compromised nodes. These false reports are forwarded to the base station. The false report injection attack causes not only false alarms, but also the depletion of the restricted energy resources in a battery powered network. The statistical en-route filtering (SEF) mechanism was proposed to detect and drop false reports en route. In SEF, the choice of routing paths largely affect the energy consumption rate and the detecting power of the false report. To sustain the secure routing path, when and how to execute the path re-selection is greatly need by reason of the frequent network topology change and the nodes's limitations. In this paper, the regional path re-selection period determination method is proposed for efficient usage of the limited energy resource. A fuzzy logic system is exploited in order to dynamically determine the path re-selection period and compose the routing path. The simulation results show that up to 50% of the energy is saved by applying the proposed method.

• Journal of The Korean Association For Science Education
• /
• v.26 no.3
• /
• pp.356-366
• /
• 2006

The purpose of this study was to investigate the effects of offering similar experiences for hypothesis-generation based on abduction. Two hundred and seventy eight students in Seoul(8th and 10th grades) were requested to propose causal questions and generate hypotheses after observing an unfamiliar situation. Then, after having been presented numerous similar experimental situations to initial situation, the students were asked to regenerate a hypothesis. When the $X^2$ analysis was done to determine differences in hypothesis generation before and after offering the similar experimental situations, a meaningful difference appeared(p<.001). This study proposes that offering similar experimental situations ease hypothesis-generation based on abductive reasoning. Additionally, the second meaningful difference was discovered when the $X^2$ analysis was carried out to find differences in causal question proposal and hypothesis generation among students who had varied cognitive levels(p<.05) Considering the findings of the study, a progressive stage offering similar scenarios may further abductive reasoning while implementing lessons related to hypothesis generation in middle and high school.