• Journal of The Korean Association For Science Education
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• v.22 no.3
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• pp.432-443
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• 2002

This study is to investigate the level of science learning concepts presented in life and matter fields of the 7th science textbooks. 6 units were analysed; 'the structure of living things', 'digestion and circulation' and 'respiration and excretion' of life field, and 'three states of matter', 'molecular motion', 'a change of state and the energy' of matter field. The gross number of concepts was 305 in life field, and 73 in matter field of the 7th science textbooks. Among publishing companies, the number of concepts was a little difference. Much more concepts in life field were presented than those in matter field. Percentages of the number of concrete and formal concepts were 58% and 42% in life, and 14% and 86% in matter field. The ratio of the number of concrete versus formal concepts was different between life and matter field. Thus, it is implied that science learning concepts are presented considering cognitive level of learner, and unit and content are constructed on the basis of properties of science fields in developing science curriculum and textbooks.

• Journal of The Korean Association For Science Education
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• v.27 no.9
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• pp.778-786
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• 2007

This study investigated the effects of analyzing mapping errors on conceptual understanding, mapping understanding and perceptions of the instructions in learning chemistry concept with analogy. Seventh graders (N=121) at two middle schools were assigned to the comparison and the treatment groups, and were taught about 'states of matter and arrangement of molecules.' The students in the comparison group were taught in the Teaching-With-Analogy (TWA) model, while those in the treatment group Were taught in the instructional model that changed 'mapping similarity' and 'indicating difference' of the TWA model into 'analyzing mapping errors.' Analysis of the results revealed that the scores of the conception test and the mapping test for the treatment group were significantly higher than those far the comparison group regardless of field dependence-independence. It was also found that most students in the two groups positively perceived the instructions with analogy, but the students in the treatment group had difficulties in analyzing mapping errors, Educational implications are discussed.

• Journal of The Korean Association For Science Education
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• v.25 no.7
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• pp.721-727
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• 2005

This study investigated the effects of small group drawing in learning the concepts of particulate nature of matter. Three classes of seventh graders (N = 126) at a coed middle school were randomly assigned to a pair drawing group, an individualistic drawing group, and a control group. The students were taught the 'three states of matter' and 'motion of molecules' for eight class periods. Prior to these classes, student self-efficacy, learning motivation, and attitude toward science instruction were examined. After instruction, tests assessing achievement, conception, learning motivation, and attitude toward science instruction were administered. Two-way ANCOVA results revealed that scores of achievement and conception for the pair drawing group were significantly higher than those for the control group. However, scores of the three groups did not significantly differ in learning motivation and attitude toward science instruction. Furthermore, no significant interactions surfaced between instruction and the level of self-efficacy in all dependent variables.

• Journal of Energy Engineering
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• v.26 no.4
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• pp.45-56
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• 2017

Coal power plants produce electricity for the nation's power grid, but they also produce more hazardous air emissions than any other industrial pollution sources. The quantity is staggering, over 386,000 tons of 84 separate hazardous air pollutants spew from over 400 plants in 46 states. In South Korea also, annual coal ash generation from coal-fired power plants were about 6 million tons in 2015. Pollutants containing particulate matter 10, 2.5 (PM10, PM2.5), heavy metals and dioxins from coal-fired power plant. The emissions threaten the health of people who live near these power plants, as well as those who live hundreds of miles away. These pollutants that have long-term impacts on the environment because they accumulate in soil, water and animals. The present study is to investigate the physical and chemical characteristics of coal-fired power plant fly ash and bottom ash contains particulate matter, whose particulate sizes are lower than $PM_{10}$ and $PM_{2.5}$ and heavy metals. There are wide commercial technologies were available for monitoring the PM 2.5 and ultra-fine particles, among those carbonation technology is a good tool for stabilizing the alkaline waste materials. We collected the coal ash samples from different coal power plants and the chemical composition of coal fly ash was characterized by XRF. In the present laboratory research approach reveals that potential application of carbonation technology for particulate matter $PM_{10}$, $PM_{2.5}$ and stabilization of heavy metals. The significance of this emerging carbonation technology was improving the chemical and physical properties of fly ash and bottom ash samples can facilitate wide re use in construction applications.

• Journal of The Korean Association For Science Education
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• v.26 no.1
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• pp.9-15
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• 2006

Students have often experienced difficulties in understanding the concept of the particulate nature of matter despite its importance in chemistry. Although various instructional methods have been suggested for teaching this concept, systematic studies have been rarely conducted. Therefore, this study investigated the effects of drawing and analyzing pictures. Three classes of 7th graders at a coed middle school in Seoul were assigned to the control group, the drawing group, and the analyzing group, respectively. Students were taught about the three states of matter and the motion of molecules for 8 class periods. The instructional effects on student conception, achievement, and science learning motivation were investigated by student visual learning styles. Results revealed that the scores of a conceptions test and a science learning motivation test for both the drawing group and the analyzing group were higher than those for the control group. Additionally, the scores of the science learning motivation test were also found to be higher for students with a more visual learning style than their counterparts.

• Tunnel and Underground Space
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• v.20 no.2
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• pp.119-124
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• 2010

Hopkinson's effect tests were carried out for various strain rates on three different types of rock in both saturated and dry states in order to examine the effects of strain rate and water saturation on tensile strength. The tensile strength increased with the increase of the strain rate not only in dry state but also in saturated state. It was also especially recognizable that the dynamic tensile strength of rock in the dry state was proportional to approximately a one-third multiple of strain rate no matter what the type of rock. It was found that water saturation decreased tensile strength in the dry state of sandstone and tuff, both with high porosity, but no significant difference could be recognized between the dry and the saturated states of granite, which has a low porosity of 0.49%.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.2
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• pp.9-20
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• 2020

The study investigates a recent surge of cash literature by using a sample of hospitality firms to gain a new understanding of corporate cash holdings. Past literature states that there is a substantial variation of liquidity across industry groups. Existing literature predominantly refers to US-listed firms and focus on either hotels or restaurants and not the hospitality industry as a whole. Therefore, we provide a comparative study of cash holdings behaviour between hospitality and non-hospitality firms from an emerging market context. Using a sample of public listed hospitality firms from 2002 to 2013, dynamic panel regression techniques are used to study the relationships between firm characteristics and cash levels. Also, the non-parametric Wilcoxon-Mann-Whitney test was carried out to examine the time and sectoral differences in cash holdings. In addition, the panel regression techniques are used to investigate the relationships between firm characteristics and level of corporate cash holdings. The results reveal that firm characteristics do matter in hospitality firms. We find that firm size, capital expenditures, and liquid assets substitutes are negatively related to cash level. The results support trade-off theory and the pecking order theory. This study incrementally explains the cash holdings behaviour of hospitality firms in emerging market.

• Journal of the Korean Institute of Navigation
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• v.16 no.2
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• pp.41-52
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• 1992

It is, as everyone knows, very important for human beings to protect and conserve marine environment. We has believed the ocean is so wide and deep that it cannot be polluted. But it has begun to doubt the capacity of self-purification of the ocean due to pollution arising from marine casualities. It has proved that semi-enclosed sea is likely to be polluted and cannot be restored easily once pollution occurs. Therefore, first of all it is important to take preventive measures for prevention of marine pollution in the semi-enclosed sea like the Yellow Sea. Many of regional conventions for prevention of marine pollution have come into existence. this dissertation was set out for the fact that the Yellow Sea is semi-enclosed sea which is vulnerable to marine pollution. It is desirable not to deal with marine preservation of the Yellow Sea by a single exclusively but to deal with it by cooperation of all coastal states under the present circumstances. I proposed a program of regional cooperation to protect and conserve the Yellow Sea. This program must be progressed with gradual arrangements. First, they must establist a basic cooperation committee to work basic affairs on the protection of marine environment within the Yellow Sea. The Committee Mainly play parts of study and research concerned with pollution of the Yellow Sea in the non-governmental side and consist of legal and scientific experts. Second, they must establish the control Committee to prevent marine pollution of the Yellow Sea substantially. There is a reason that regional cooperation cannot be directly concluded with the regional tready. Because there is a problem of Recognition of States left. In principle, a subject of tready must be a state in the International Law. But they have not made Recognition of State which is demanded by International Law between North and South Koreas. Therefore, the Control committee must play a substantial part of prevention from pollution instead of the treaty. Finally, we concluded tentatively named $\ulcorner$Convention on Regional Cooperation for Protection of Marine Environment of the Yellow Sea from Pollution$\lrcorner$ if the matter is settled which is related to Recognition of States in the International Law.

• Journal of Animal Science and Technology
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• v.63 no.4
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• pp.799-814
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• 2021

Information is lacking about the effect of date of a fall cut of alfalfa (Medicago sativa L.) on dry matter yield (DMY), forage nutritive value, and stands persistence. The objective of this study was to determine the effect of timing of a fall cut on DMY, forage nutritive value and stand persistence of three alfalfa varieties: low-lignin Hi-Gest 360, Roundup Ready Tonica, and conventional Gunner in Northeastern Kansas in the United States. The field study was carried out by splitting plot in randomized complete block design with four replications. The harvesting data of different maturity stages were collected in each year from 2015 to 2018. Three cuts were harvested based on the stage of maturity, and the last (fourth) cut was done on September 15, September 30, October 15, and October 30 of each year. The persistence of the alfalfa stands was determined each fall after the last cut, and each spring after the first cut, by counting the number of live plants in a randomly placed quadrat in each plot. Alfalfa cut on September 15 and September 30 had a higher stand persistence compared to alfalfa cut on October 15 and October 30. The DMY of the first cut in 2016 was significantly higher in roundup ready than the low-lignin alfalfa variety. In the second cut, DMY was significantly higher in conventional alfalfa than the roundup ready. There were no significant differences in DMY between alfalfa varieties in the rest of seasonal cuttings in 2016 and 2017 and annual total yield in both years. In general, low lignin alfalfa variety had higher crude protein and relative feed value and lower acid detergent fiber and neutral detergent fiber contents than those in roundup ready and conventional alfalfa varieties. On average, nutritive value of alfalfa was generally affected by last cutting dates in 2017. Based on 3-year data the last cutting of alfalfa in the fall could be done by September 30-October 15 without harmful effect on DMY.

• Journal of Korean Society of Forest Science
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• v.76 no.3
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• pp.249-255
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• 1987

Forestry as with all land matters, under the Constitution, is a State matter. Thus the States, numbering 14, have considerable autonomy in decisions on forestry and related matters. However, the Federal Government, having jurisdiction over such issues as defence, education and research, endeavours to coordinate, standardise and advise the States on matters where the States have jurisdiction. However, forestry being a major revenue earner, is jealously guarded by the States. Under such circumstances and recognising the interdependencies of impacts of decisions at the State level, the institutional organisations play an important role in coordinating state activities to ensure that the benefits to the country as a whole are not sacrificed in favour of interests of individual state. Various legislative mechanisms have been established to ensure this coordinated effort. A National Forestry Council forms the apex of national political coordination. The Federal Forestry Department is responsible for coordination of developmental activities at the State level, which are implemented be the State Forestry Departments within Peninsular Malaysia. Research is carried out centrally by the Forest Research Institute of Malaysia(FRIM), a statutory body formed in 1985 from a research division of the Forestry Department. The Stares of Sabah and Sarawak have their own Forestry Departments, independent of the Federal Department, and each with its own research unit independent of FRIM. Tertiary education in forestry is the sole responsibility of the Agricultural University at Serdang with a campus for Diploma level training in Sarawak. In the developmental area in the State of Sabah, institutions have been formed to focus on specific areas of activities. The Sabah Foundation is responsible for the long term development of the State forests with a concession of about one million ha. Sabah Forest Development Authority(SAFODA) was formed to carry out reforestation of denuded areas. Sabah Forest Industries Ltd.(SFI) is responsible for the country's only integrated pulp and paper industry with its own afforestation program to support its resource supply. In Peninsular Malaysia various states have established State Corporations to manage large "sustained yield" concessions. While wildlife and state parks are managed by the respective forestry departments in Sabah and Sarawak, it is the responsibility of a separate department in Peninsula Malaysia called the Department of Wildlife and National Parks(under the Ministry of Science, Technology and Environment). Timber trade legislation and promotion in the Peninsular is the responsibility of the Malaysian Timber Industries Board(MTIB) for Peninsular Malaysia and the Sarawak Timber Industries Development Corporation(STIDC) in Sarawak. In the area of NGOs ; the Institute of Foresters Malaysia, is the professional body of forestry in the country. A Malaysian Forestry Society caters for the public participation and interest. Other environmentally related NGOs such as the Malayan Nature Society, the Environmental Protection Society, World Wildlife Fund, Friends of the Earth and the Consumers Associations also involve themselves in specific forestry activities. A number of timber trade associations are also formed by the private sector to assist the industries.