• Journal of Science Education
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• v.37 no.1
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• pp.221-232
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• 2013

The purpose of this study was to examine the effect of the CoRe-based density unit class on conceptual formation and on learner satisfaction with the class. For this study, two hundred and forty 8th grade students were chosen from six classes. The students were divided into two groups: an experimental group, which received a CoRe-based density unit lesson, and a control group, which was taught based on traditional teaching method. The CoRe-based density unit classes consisted of 4 periods based on the analysis of the previous studies on CoRe about density. The results showed the meaningful significant difference between the CoRe-based classes and the classes based on traditional teaching method both in the posttest on the extent of the conceptual formation on the density and in the retention test. The difference suggests that the lesson with CoRe is based on the consideration of the difficulties and limitations students face in various fields such as the students themselves, teachers, learning environment, evaluation, etc. during their learning process and even in the types of preconception they have, and the CoRe-based lesson is centered around the best teaching strategies to solve such difficulties. As a result of the analysis on the experimental group's class satisfaction, it is revealed that the students with a high level of attitudes related science or with a high level of science achievement showed especially high satisfaction in their learning. Analysis of questionnaire survey showed that the students in the experimental group got the opportunity through CoRe-based lesson to stretch their thoughts and ideas in a free way and preferred a teaching method which didn't just show the concept, but allowed them to find it for themselves or which let them predict the solution and then confirm the result on their own and a lesson which encouraged their active participation.

• Journal of Korean Society of Rural Planning
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• v.20 no.1
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• pp.37-49
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• 2014

With the globalized coming of the knowledge-based society following the post-industrial period, both the crises and opportunities have been occurring together as non-special affairs, which is the same situation in Rural Korea. A crucial key for maximization of potentialities of emerging opportunities is to mobilize the multi-valuedness embedded in rural areas as one of new growth powers. In order to realize a variety of multi-valuedness of rurality, it should be needed to re-discover and re-evaluate rural resources by paradigm shift and to identify the multi-valuedness of resources systematically and scientifically. On the basis of this understanding, this study aimed at setting up the evaluation indicators system by rural village types to identify systematically the multi-valuedness embedded in rural villages in the initial step. Integrated evaluation indicators system was made with 4-level hierarchies; high-leveled one with 3 fields(society, environment, regional economy); middle-leveled one with 8 areas; lower-leveled one with 19 sub-areas; detailed indicators totally with 39 items. These indicators were divided into 12 basic indicators applied to all types and 27 specialized indicators determining the characteristics of village types.

• Journal of Korea Trade
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• v.26 no.2
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• pp.65-83
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• 2022

Purpose - The purpose of this study is to evaluate the economic effects of FTAs using the concept of value-added exports. So far, the economic effects of FTAs have been dependent on decrease in import prices due to tariff cuts in importing countries, but the actual tariff reduction need to consider the value added of the exporting countries. Design/methodology - Value-added export refers to the added value created in the exporting country out of total exports. Among value-added exports, direct value-added export is interpreted as the Regional Value Contents (RVC), from which the economic effect of the FTA can be analyzed. A modified GTAP-VA model takes into account RVC in order to estimate accurate effects of FTAs. Findings - By the re-evaluation of the FTA based on the RVC, this paper makes it clear that the economic effects of the existing FTA methodology have the possibility of overestimation. In addition, as a new FTA with a strengthened Rules of Origin (ROO) is being initiated, a negative impact on international trade and GVC utilization may occur. Originality/value - This study introduces the concept of value-added export in analyzing the effects of FTAs. The new analysis methodology of this paper emphasizes the importance of value-added exports. Re-organization of GVCs would change regional trade agreements and empower ROO by weakening existing GVCs and transforming the value chain from global into regional scope.

• Korean Journal of Head & Neck Oncology
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• v.35 no.2
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• pp.11-17
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• 2019

Background/Objectives: Papillary thyroid carcinoma (PTC) has generally an indolent character with a good prognosis. However, recurrence remains a major concern for the patients during their lifetime. Despite the slowly progressing character of PTC, recurrence can occur within a short period after initial surgery. This study aimed to determine the clinical findings and cause of recurrence in patients who underwent re-operative surgery due to neck node recurrence by reviewing the CT (computed tomographic) scan imaging of the recurrence of PTC retrospectively. Materials & Methods: We reviewed the medical records of patients referred to Ajou University Hospital from January 2002 to January 2018. All patients had re-operative surgery due to neck node recurrence and CT scan results of preoperative evaluation and postoperative follow up. Over this period, 110 patients who underwent re-operation due to neck node recurrence with a CT scan were included in our cohort, resulting in a total of 220 re-operations. Results: The time from initial operation to first re-operation was examined in 110 patients. The median time to re-operation was 28 months, with a range of 4 months to 186 months. Most re-operations (82.7%) occurred within the first five years, 43.6% were in the first two years from the initial surgery. The result of the retrospective CT review showed newly developed cases (21,19.1%), missed diagnosis cases (42,38.2%), real recur cases after surgery (33,30.0%), and remnant lymph nodes (LNs) cases (14,12.7%). We further sub-analyzed 14 cases with remnant LNs. Reasons for remnant LNs included insufficient operation (N=5) and beyond general surgical extent. (N=9). Conclusion: Re-operation due to cervical lymph node recurrence is mostly a persistent disease. They included a missed diagnosis and incomplete operation. These finding may reduce the reoperation of cervical lymph node recurrence by accurate preoperative evaluation and complete surgical resection at the initial surgery.

• Korean Journal of Plant Resources
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• v.19 no.1
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• pp.112-119
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• 2006

We investigated the changes in the volatile flavor components of domesticated Codonopsis lanceolata, which were packed in woven polypropylene (WP) film or low density polyethylene (LDPE) film and stored for 15 and 30 days at refrigerated ($2{\sim}4^{\circ}C$) or room ($18{\sim}20^{\circ}C$) temperature (hereafter referred to as WP-RE-15, WP-RO-15, LDPE-RE-15, LDPE-RO-15, WP-RE-30, WP-RO-30, LDPE-RE-30 and LDPE-RO-30). 167 volatile flavor components were identified in the fresh domesticated Codonopsis lanceolata by GC/MS. The volatile flavor components which were identified in the domesticated Codonopsis lanceolata stored for 15 days were as follows ; LDPE-RE (117 components), WP-RO (65 components), WP-RE (49 components), and LDPE-RO (48 components). After 30 days, the numbers of components were as follows : LDPE-RE (99 components), WP-RO (94 components), WP-RE (46 components), and LDPE-RO (85 components). In all conditions, the following 7 volatile flavor components were identified; 1-hexadecene, 2,6-dimethyl-2-octanol, 2-methyl-2-dodecanol, ${\alpha}$-cedrene, ${\beta}-selinene$, farnesane, and isoledene. According to the sensory evaluation, the freshness of domesticated Codonopsis lanceolata was best maintained with LDPE film and under chilled conditions.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.5
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• pp.165-173
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• 2015

People with color vision deficiency (CVD) experience difficulties in discriminating some color combinations and color differences due to the abnormal retinal cone systems. While there exist smartphones with a re-coloring function for CVD, monitors do not provide the re-coloring function. In this paper, we propose a new re-coloring algorithm that adjusts the displayed colors for CVD using a color controller embedded in the monitor. The proposed algorithm converts the hue and saturation in HSV color space, according to the type and strength of the color deficiency. The results of the performance evaluation with a certain number of people with CVD show that the proposed system can convert colors imperceptible into perceptible.

• Journal of Information Technology Applications and Management
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• v.23 no.3
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• pp.71-86
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• 2016

This paper proposes a new software quality model composed of a hierarchy of software quality views and three software quality characteristics models. The software view hierarchy is composed of two levels : end view and means view at the first level, contingency view and intrinsic view as sub-views of means view. Three software quality characteristics models are activity quality characteristics model, contingency quality characteristics model, and intrinsic quality characteristics model, which correspond to end view, contingency view, and intrinsic view respectively. This paper also reclassifies characteristics of ISO/IEC 25000 series SQuaRE's software product quality model according to the proposed software quality model. The results illustrate clearly the shortcomings of SQuaRE's product quality model and how to overcome them. First of all, most of SQuaRE's product characteristics should be redefined and conceptually clarified according to the views on which they are really rested. Much more characteristics should be supplemented too. After that, rigorous empirical researches will become relevant. Causal relationships between activity quality characteristics and characteristics of means view should be empirically researched.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.1
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• pp.108-113
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• 2020

Pinions are generally heavy and integrated with a shaft. Thus, fabricating a pinion is a material- and machining-intensive task characterized by low productivity. Contact of the output pinion with a sliding surface or a cloud contact causes loss of power because of friction. Consequently, the output pinion undergoes considerable wear and tear at its ends, which adversely affects the overall transmission efficiency of decelerators. To improve transmission efficiency and extend gear life, an optimum output pinion design is required. To this end, in this study, an output pinion for worm gear decelerators was designed and optimized by means of product verification through prototyping and performance evaluation to improve gear life and productivity. The optimized design was validated and subjected to structural analysis.

• Journal of the Society of Naval Architects of Korea
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• v.57 no.3
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• pp.152-159
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• 2020

Ship owners had pursued higher benefits by demanding the new design and construction of ships with higher operational efficiency. There was a necessity for shipyards to suggest a more economical design and advanced operation concept in order to meet the demands. Especially, since BOG combustion and activation of the re-liquefaction unit had to be taken into account in ship design in addition to fuel oil and gas consumption, the evaluation of the operating efficiency considering the technological trends was necessary. In this paper, it was aimed to study the design philosophy and operation strategy by considering the effect of fuel oil and gas consumption, BOG combustion, and activation of the re-liquefaction unit on the operating cost for laden voyage according to ship speed, BOR, and activation of the re-liquefaction unit. For this purpose, the costs were acquired by conducting the sailing simulation of an LNGC based on a mathematical model including the maneuvering equations of motion. The design philosophy and operation strategy was reviewed in terms of the operating cost.

• Safety and Health at Work
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• v.4 no.1
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• pp.12-26
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• 2013

In concert with the development of new materials in the last decade, the need for toxicological studies of these materials has been increasing. These new materials include a group of rare earths (RE). The use of RE nanotechnology is being considered in some green applications, to increase their efficiency by using nano-sized RE compounds, and therefore hazard evaluation and risk assessment are highly recommended. This review was conducted through an extensive contemplation of the literatures in toxicology with in vitro and in vivo studies. Major aspects reviewed were the toxicological evaluations of these elements and metallic compounds at the molecular and cellular level, animal and human epidemiological studies and environmental and occupational health impacts on workers. We also discuss the future prospect of industries with appliances using RE together with the significance of preventive efforts for workers' health. To establish a safe and healthy working environment for RE industries, the use of biomarkers is increasing to provide sustainable measure, due to demand for information about the health risks from unfavorable exposures. Given the recent toxicological results on the exposure of cells, animals and workers to RE compounds, it is important to review the toxicological studies to improve the current understanding of the RE compounds in the field of occupational health. This will help to establish a sustainable, safe and healthy working environment for RE industries.