• Korean Journal of Medicinal Crop Science
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• v.17 no.6
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• pp.421-426
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• 2009

The purpose of this study was to identify soil physical characteristics as guideline for high yield potential in ginseng cultivated field which produced 6 years root. Harvest yields of ginseng to be divided by parent rock was in order of phyllite and red shale 3.1 kg/$3.3\;m^2$ > granite and gneiss schist 3.0 kg > basalt 2.6 kg > porphyry 2.2 kg in upland and forest soil. Also, with classified by topography, it was in order of foot slope and alluvial fan 3.2 kg/$3.3\;m^2$ > valley 3.0 kg > low hill 2.9 kg > hill, lave flow and dilluvial terrace 2.8 kg in survey tilth. Class determination of soil texture, it was in order of sandy loam 3.1 kg/$3.3\;m^2$ > loam and silt loam 3.0 kg > clay loam 2.9 kg > silt clay loam 2.8 kg in survey tilth. Slope condition of farming land, in case of sloping (2~7%), it was 3.1 kg/$3.3\;m^2$ but deep sloping (15~30%) caused decreasing harvest yield. In drainage classes (excessively, well and moderately well), there was no significantly different in harvest yields. Relationship between harvest yield and soil series, Production sites as yielding 3.0 kg/$3.3\;m^2$ were seven sites, also it was contained 14 soil series. Production sites as yielding 2.5~3.0 kg/$3.3\;m^2$ were eleven sites, it was contained 16 soil series. Production sites as yielding 2.0~2.5 kg/$3.3\;m^2$ were 10 sites, it was contained 4 soil series.

• Journal of the Korean association of regional geographers
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• v.3 no.1
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• pp.13-34
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• 1997

The impact of a central place on daily living over wide outlying territory has been one of traditional subjects in the field of urban geography. The flow of rural population toward the central city of Chinju characterizes the population movement in Western Kyungnam, where the spillover of urban population into outlying areas, an especially prominent phenomenon in American society, does not occur. The central city of Chinju is supposed to be the most favored settlement area in Western Kyungnam. More than two thousands of teachers. who live in Chinju, cross the city boundary each morning to do their jobs in Western Kyungnam. But only ninety teachers living outside Chinju commute to the workplace in the city. The teachers willingly spend hours commuting each day to enjoy better quality of life in the central city. In fact, the central city of Chinju functions as bedroom communities for many middle-class workers in Western Kyungnam. On the basis of teachers' commuting behavior, four levels of Chinju's urban spheres are identified in Western Kyungnam. As Table-6 and Figure-2 show, the first-order level of Chinju's sphere includes most Myuns of Sanchung/Hadong Guns and some Myuns of Sachun/Gosung Guns. The second-order level comprises Sanchung/Sachun Eubs and many Myuns of Sachun /Gosung Guns. The third-order level is made up of Samchunpo, Hadong/Gosung/Eryung/Namhae/Habchun/Hamyang Eups, and many Myuns of Eryung/Namhae/Habchun Guns. And all of Guchang Gun and most Myuns of Hamyang Gun belong to the fourth-order level of Chinju's sphere. The influence sphere of Metropolitan Chinju is extended farther in the direction of less competition with other metropolises. Such a situation occurs to the west and south of Chinju. Daily commuting, defined as the journeys to and from work, is an excellent indicator for delimiting urban spheres of influence.

• Journal of Internet of Things and Convergence
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• v.7 no.3
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• pp.63-68
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• 2021

Domestic electric heater manufacturers are focusing on technology development to improve the efficiency of existing products. The electric heater for ship fuel is large in size and has high difficulty in miniaturization/high efficiency, so there are not many companies that try to develop technology yet. The existing electric heater has a structure of low heating efficiency because the contact time with the heat exchange tube of the heating medium is very short because the flow path of the ship engine fuel is monotonous. Since it is manufactured in a tubular shape, the volume is very large regardless of the heating efficiency. As a result, the tubular electric heater device applied by overseas advanced companies has difficulty in maintaining and repairing because it is necessary to decompose all tubular heaters when a specific part of the inside is damaged and if the heat exchange tube is damaged, all the heat exchange tubes must be decomposed. In this study, a basic study on plate type electric heaters capable of heating 10 tons of ship engine fuel per hour and setting a maximum temperature of up to 150℃ was conducted through a 250kW capacity plate type electric heater.

• Korean Journal of Environment and Ecology
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• v.32 no.6
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• pp.591-602
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• 2018

Clithon retropictus has been designated as an endangered wildlife Class II due to its high value as a biological indicator species capable of judging environmental quality such as salinity, water flow, and ground conditions. However, basic research on its physiological and ecological characteristics is still lacking. As such, this study intended to examine the impact of environmental conditions such as salinity and soil particle size on the size and density of Clithon retropictus at the Yeoncho river estuary. The investigation of the salinity, which is a key variable that affects the distribution of organisms in the estuary, showed that Clithon retropictus could grow at a salinity ranging from 0#x2030; (freshwater) to 25‰ (brackish water). The coarse gravel (19-75mm) tended to increase nearer the upper stream (under the Yeoncho weir), while the proportion of particles smaller than sand (less than 19mm) increased toward the downstream. The population and the size of the individuals decreased rapidly in the downstream where water stagnated near the Yeoncho weir, and the salt water joined. The results indicated that Clithon retropictus had a high tolerance to salinity, but the adaptability was weaker toward the extremes since the population, and the size tended to decrease as the salinity increased. The correlation analysis revealed that both salinity and soil particle size affected the population and individual size. The correlation between the individual size and salinity was -0.242 (P <0.01), indicating that the size decreased with increasing salinity. The correlation between individual size and coarse gravel having a particle size of 19mm or more was 0.420 (P <0.01), indicating that the size increased with increasing the particle size.

• Journal of the Korean Institute of Gas
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• v.23 no.4
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• pp.46-64
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• 2019

Technical practice code, KGS GC101 2018, for explosion hazard area selection and distance calculation of gas facility was enacted and implemented from July 12, 2018. This code includes whole contents of IEC60079-10-1 2015 (Explosive atmospheres Part 10-1: Classification of areas - Explosive gas atmospheres), and clarifies the interpretation of ambiguous standards or adds guidelines for standards. KGS GC101 is a method for classifying explosion hazard place types: (1) Determination of leak grade (2) Determination of leakage hole size (3) Determination of leakage flow (4) Determination of dilution class (5) Determination of ventilation effectiveness, finally (6) Determination of danger place (7) Explosion The range of dangerous places can be estimated. In order to easily calculate this process, the program (KGS-HAC v1.14, C-2018-020632) composed by Visual Basic for Application (Excel) language was produced by Korea Gas Safety Corporation. We will discuss how to use codes and programs to select and set up explosion hazard zones for field users.

• Journal of The Korean Association For Science Education
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• v.39 no.1
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• pp.73-88
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• 2019

The purpose of this study is to explore elementary teachers' difficulties on teaching science by analyzing questions that have been posted for a long time in an autonomous online teacher community named Indischool. For this purpose, 409 question postings(the 2007 and 2009 revised curriculum, third to sixth grade) were analyzed using the framework for analyzing questions about elementary teachers' science teaching(modified from Alake-Tuenter et al., 2013). The study revealed that there were more science-SMK questions than science-PCK questions, and most of the questions were 'about lenses' and 'in 2014 and 2015, when the curriculum was changing from the 2007 to the 2009 revised curriculum'. The long-standing difficulties in science-SMK were 'an application of facts and concepts in lenses' and 'an unexpected experimental error in electricity'. In particular, there are the principle of transparent cup-shaped objects acting as lenses, the process of image formation by convex lenses, experimental errors of 'compass movement due to current flow change' and experimental errors 'serial connection of bulbs'. The long-standing difficulties in science-PCK were 'understanding and response to context' and 'understanding and response to aims mentioned in standard document' and these are not related to physical units but to others. In particular, there are request class materials, activity ideas at the end of the semester and understanding the national curriculum guidelines. These teachers' difficulties should be reflected in the science teaching support system like a teacher's guide compilation, teacher's training curriculum development, etc.

• Biomolecules & Therapeutics
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• v.31 no.1
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• pp.73-81
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• 2023

Sirtuins (SIRTs) belong to the nicotinamide adenine dinucleotide (NAD+)-dependent class III histone deacetylase family. They are key regulators of cellular and physiological processes, such as cell survival, senescence, differentiation, DNA damage and stress response, cellular metabolism, and aging. SIRTs also influence carcinogenesis, making them potential targets for anticancer therapeutic strategies. In this study, we investigated the anticancer properties and underlying molecular mechanisms of a novel SIRT1 inhibitor, MHY2251, in human colorectal cancer (CRC) cells. MHY2251 reduced the viability of various human CRC cell lines, especially those with wild-type TP53. MHY2251 inhibited SIRT1 activity and SIRT1/2 protein expression, while promoting p53 acetylation, which is a target of SIRT1 in HCT116 cells. MHY2251 treatment triggered apoptosis in HCT116 cells. It increased the percentage of late apoptotic cells and the sub-G1 fraction (as detected by flow cytometric analysis) and induced DNA fragmentation. In addition, MHY2251 upregulated the expression of FasL and Fas, altered the ratio of Bax/Bcl-2, downregulated the levels of pro-caspase-8, -9, and -3 proteins, and induced subsequent poly(ADP-ribose) polymerase cleavage. The induction of apoptosis by MHY2251 was related to the activation of the caspase cascade, which was significantly attenuated by pre-treatment with Z-VAD-FMK, a pan-caspase inhibitor. Furthermore, MHY2251 stimulated the phosphorylation of c-Jun N-terminal kinase (JNK), and MHY2251-triggered apoptosis was blocked by pre-treatment with SP600125, a JNK inhibitor. This finding indicated the specific involvement of JNK in MHY2251-induced apoptosis. MHY2251 shows considerable potential as a therapeutic agent for targeting human CRC via the inhibition of SIRT1 and activation of JNK/p53 pathway.

• Journal of Korea Water Resources Association
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• v.56 no.9
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• pp.553-562
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• 2023

The Gobiobotia naktongensis is a species endemic to Korea, and it has recently been designated as a class I endangered species of freshwater fish. Naeseong Stream, one of the tributaries of the Nakdong River, where the Gobiobotia naktongensis was first discovered, provided an optimal habitat for the Gobiobotia naktongensis in the past with fine sand beds and riffle. Currently, due to the construction of Yeongju Dam and the excessive dredging of river channels by the local government, the riverbed armoring in the downstream area of the dam is undergoing rapid changes, and as a result, the habitat environment of the Gobiobotia naktongensis is deteriorating. In this study, the variations of the habitat suitability of the Gobiobotia naktongensis due to the change in the riverbed grain size of the Naeseong Stream were analyzed based on the WUA (weight usable area) using the physical habitat model, River2D. The study domain is the reach from Seoktap Bridge to Hoeryong Bridge downstream of Yeongju Dam. The change in riverbed grain size was analyzed using D50 acquired in 2010 and 2020, respectively. The substrate grain size of Naeseong Stream in 2020 was thicker than that in 2010, and the riverbed coarsening phenomenon was evident overall. As a result of the River2D analysis, the area in which the Gobiobotia naktongensis could inhabit was only about 0.75% in 2010 compared to the entire area of the flow, and even this decreased to 0.55% in 2020 due to riverbed armoring.

• 한국체육학회지인문사회과학편
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• v.54 no.5
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• pp.233-250
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• 2015

In this study, changes and emotions that result from doing yoga and the influence of yoga on daily lives were investigated by using causal network. This information was gathered from interviews and outlined in a diagram form. By checking the daily participation records of 77 participants who took a yoga class as part of the cultural studies curriculum at H University, general factors related to change were extracted and then 7 participants were chosen for in-depth interviews. In the interviews, the changes experienced from doing yoga and the emotions caused by the change and the influence this change had on daily lives were documented and the collected results were displayed in a diagram using causal network according to the flow of questionnaire. As a result, the changes experienced through doing yoga were divided in 4 categories: physical function, emotional, cognitive and physiological changes. Each change and emotion caused by the change were shown to have an influence on daily lives. Through schematized causal network for each change, the changes and emotions which the participants experienced and the influence of yoga on daily lives could be checked. Based on the study results, the effect of yoga, the need for various approaches to examine the effect exercise has on emotions and the applicability of causal network that can be employed as a creative and effective quantitative data analysis method were discussed.

• Journal of the Korean Society for Library and Information Science
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• v.57 no.2
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• pp.179-198
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• 2023

The purpose of this study is to verify the role of teacher librarians by examining the cases of media and information literacy(MIL) classes in the joint curriculum of high school credit system research school. The classes were two 34th classes joint curriculum established by two teacher librarians at the high school credit system research school. Individual students set their own inquiry problems integrated with their careers or subjects, and teacher librarians guide the process of solving them based on the process of using MIL. The participants were 22 high school students in Daegu who filled out the questionnaire before and after completing the course. The effect of the classes was analyzed through a questionnaire consisting of 42 questions for the 3 factors of access, evaluation, and creation, which are the components of MIL announced by UNESCO. As a result, all 3 factors and 25 of the sub-42 survey items showed a statistically significant difference before and after class, It was investigated that literacy of students improved through MIL education of teacher librarians. Through this study, it will be possible to expand the awareness of the effect of the educational role of teacher librarians in the flow of future curriculum.