• Journal of Korean Society of Forest Science
• /
• v.73 no.1
• /
• pp.14-20
• /
• 1986

The processing times of the works, chainsaw felling, axe trimming and hand skidding to the corridor, by one-man-work method per single pole timber were investigated in the thinning young Japanese larch stand at the Training Forests of the Forest Work Tranining Center in Kangwon-do. The works were performed by a skilled worker with the craftman qualification and 69 trees were cut. Time was checked at intervals of 25/100 minute by the multimoment method and the worker's efficiency was evaluated for every cycle. Total working time was 8.11 hours of which 90% was for thinning work and 10% for cleaning work. Of the total working hours, 82.7% was net working time, 12.3% was general working time and 4.9% was non-valuated time. Of the net working time, 5.9hours, for only thinning, 20.9% was spent on moving to the feeling tree, 27.1% was spent on felling, 40.5% was spent on trimming and 11.5% was spent on skidding to corridor. Net chainsaw operating time was 0.94 hour which included 0.2 hour for cleaning work. Of the net chainsaw operating time, 0.94 hour, 66% was operating time and 34% was idle running time. The basic and general working times by DBH classes with application of 130% worker's efficiency calculated from regression equations were shown in table 1. For better practical using of this table, the simplified proposal was given in table 2.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.20 no.6
• /
• pp.427-446
• /
• 2008

A review on the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2006 has been accomplished. Focus has been put on current status of research in the aspect of heating, cooling, ventilation, sanitation and building environments. The conclusions are as follows. (1) The research trends of fluid engineering have been surveyed as groups of general fluid flow, fluid machinery and piping, etc. New research topics include micro heat exchanger and siphon cooling device using nano-fluid. Traditional CFD and flow visualization methods were still popular and widely used in research and development. Studies about diffusers and compressors were performed in fluid machinery. Characteristics of flow and heat transfer and piping optimization were studied in piping systems. (2) The papers on heat transfer have been categorized into heat transfer characteristics, heat exchangers, heat pipes, and two-phase heat transfer. The topics on heat transfer characteristics in general include thermal transport in a cryo-chamber, a LCD panel, a dryer, and heat generating electronics. Heat exchangers investigated include pin-tube type, plate type, ventilation air-to-air type, and heat transfer enhancing tubes. The research on a reversible loop heat pipe, the influence of NCG charging mass on heat transport capacity, and the chilling start-up characteristics in a heat pipe were reported. In two-phase heat transfer area, the studies on frost growth, ice slurry formation and liquid spray cooling were presented. The studies on the boiling of R-290 and the application of carbon nanotubes to enhance boiling were noticeable in this research area. (3) Many studies on refrigeration and air conditioning systems were presented on the practical issues of the performance and reliability enhancement. The air conditioning system with multi indoor units caught attention in several research works. The issues on the refrigerant charge and the control algorithm were treated. The systems with alternative refrigerants were also studied. Carbon dioxide, hydrocarbons and their mixtures were considered and the heat transfer correlations were proposed. (4) Due to high oil prices, energy consumption have been attentioned in mechanical building systems. Research works have been reviewed in this field by grouping into the research on heat and cold sources, air conditioning and cleaning research, ventilation and fire research including tunnel ventilation, and piping system research. The papers involve the promotion of efficient or effective use of energy, which helps to save energy and results in reduced environmental pollution and operating cost. (5) Studies on indoor air quality took a great portion in the field of building environments. Various other subjects such as indoor thermal comfort were also investigated through computer simulation, case study, and field experiment. Studies on energy include not only optimization study and economic analysis of building equipments but also usability of renewable energy in geothermal and solar systems.

• Korean journal of applied entomology
• /
• v.60 no.2
• /
• pp.255-262
• /
• 2021

The potato tuber moth, Phthorimaea operculella (Zeller) has been known as a quarantine pest of potato. This study investigated inhibition doses of electron beam irradiation (EBM) by comparing their effects on the development and reproduction and DNA damage of the insect pest. Eggs (0-12 h old), larvae (3^rd and 5^th instar), pupae (less than 1 d old after pupation) and adults (less than 1 d old after emergence) were irradiated with increasing doses of EBM. The EBM with 150 Gy could not completely prevent the hatchability of eggs and pupation of the hatched larvae. The hatchability from the irradiated eggs were 19.3%. However, adult emergence from the irradiated eggs were completely inhibited. When 3^rd and 5^th instar larvae were irradiated at 100 Gy, the adult emergence from the irradiated larvae and the fecundity of the adults were completely inhibited. When pupae and adults were irradiated at 300 Gy and 400 Gy, respectively, the hatchability of the F₁ eggs was completely inhibited. The alkaline comet assay on the level of DNA damage by EBM in P. operculella adults indicates that the EBM increased DNA damage level in a dose-dependent manner, and the damage was repaired in a time-dependent manner. These results may recommend EBM of 150 Gy as a phytosanitary treatment for P. operculella. However further confirmative study is required for the practical application of this EBM dose for P. operculella disinfestation.

• 대한공업교육학회지
• /
• v.44 no.1
• /
• pp.52-71
• /
• 2019

The quality of school education is a key element for national education development. An important factor that determines the quality of school education is qualities of teachers who are in responsible for school education in the field. Therefore, it is necessary to hire competent teachers in the teacher appointment exam for the secondary school. This necessity is evident especially for vocational high schools and Meister high schools with the introduction of 2015-revised curriculum based on NCS that separates each three subjects, "Electrical, Electronics Communication" resulting in the change of question mechanism, which requires new designing of assessment and content area. So, this study analyzes curriculum in college of education for "Electrical", "Electronics", "Communication", 2015-revised curriculum based on NCS and the development of standards for teacher qualifications and assessment area and evaluation of teaching ability in the subjects of the teacher appointment exam, "Electrical, Electronics Communication" Engineering" in 2009. The assessment area and content elements of "Electrical", "Electronics", "Communication are extracted from the analyzed results and they are verified by experts' consultation and presented as follows; First, the assessment area and content elements of the "Electrical" subject were designed to evaluate the NCS - based 2015 revised curriculum by presenting the NCS learning module to the evaluation area and content element in the basic subject "Electrical and Electronics Practice". Second, the section of "Electronics" presented the assessment area and content elements applying the Electronic Circuit, basic subject of the NCS and it also added "Electromagnetics", which is the basic part of Electronics in the Application of Electromagnetic waves that could be applied to the assessment. Third, the assessment area and content elements of "Communication" consist of the communication-related practice that is based on "Electrical" and "Electronic", considering the characteristics of "Communication Engineering". In particular, "Electrical and Electronics practice" which adds network construction practice and communication-related practice makes it to be able to evaluate the communication-related practical education.

• Korean Journal of Heritage: History & Science
• /
• v.49 no.1
• /
• pp.146-165
• /
• 2016

With the introduction of the system of recognizing masters of craft and performance skills in 1970, the principle of "preserving the original form," which was already in general use, was adopted as a legal principle in the Cultural Heritage Protection Act. While the concept "original form" can be related to tangible elements of heritage through the Act, the intangibility of craft and performance skills does not allow their pinpointing at a particular temporal period or the identification of a particular master from the past as the basis of an original form. Therefore, those craft or performance skills that are available at the point of recognition of relevant masters must serve as the basis of the original form for the intangible heritage concerned. This means that the principle of preserving the original form of intangible heritage has been implemented not based on a fundamental form of materiality, but rather on the craft or performance skills that may be held by a master at the time of his/her recognition as a "temporary original form." This principle has been observed through intangible heritage transmission and education policies for recognized masters and their trainees, contributing to establish an elitist transmission environment in which public were denied to join the education on intangible heritage. Even with policies guided by the principle of preserving the original form, designated craft and performance skills have been transformed contingent upon given social and environmental conditions, thus hindering the preservation of the original form. Despite the intrinsic limitations of the principle of preserving the original form when applied to intangible heritage, this principle has served as a practical guideline for protecting traditional Korean culture from external influences such as modernization and Westernization, and also as an ultimate goal for the safeguarding of intangible heritage, engendering actual policy effects. The Act on the Safeguarding and Promotion of Intangible Cultural Heritage that comes into effect in March 2016 takes the constantly evolving nature of intangible heritage into consideration and resultantly adopts a concept of "essential form" (jeonhyeong) in place of "original form" (wonhyeong). This new concept allows for any transformations that may take place in the environment surrounding the intangible heritage concerned, and is intended to mitigate the rigidity of the concept of "original form." However, it should be noted that "essential form," which is manifested as the unique significance, knowledge, and skills delivered by the intangible heritage concerned, should be maintained according to the guidelines and principles related to heritage conservation. Therefore, the new concept can be understood not as a rupture, but more as a continuum of the concept of "original form."

• Journal of Science Education
• /
• v.42 no.3
• /
• pp.371-389
• /
• 2018

This study focuses on the fact that students and teachers commonly have difficulty in 'selecting the topic' in many activities including student-led research that is conducted from topic selection to the drawing of conclusion. The purpose of this study is to develop a manual for science teaching research. The instructional manuals of 4 stages were developed based on practical knowledge that can be implemented in the actual class through previous research and literature. Each stage is composed of , , , and . In the third stage, students are expected to find scientific questions and develop them into research topics through detailed class research on newspaper articles, scientific magazines, traditional knowledge, proverbs, daily life, and textbook experiments. In the experimental group, the final research topic was selected through a variety of sources such as textbook experiments, proverbs, YouTube images, newspaper articles, individual WHY NOTEs, and understood the conditions of the scientific research topic and expressed the variables in the research title. However, in the control group, some students did not consider the research scope of the selected research subjects to be specific or not to be able to study at their level. As a result of giving the students as much autonomy as possible, many groups did not fully understand the previous research and submitted it. Based on the results of this study, it can be concluded that development and use of a 'topic selection stage' centered practice manual for general high school teachers would not only improve the students' abilities to discover solutions to scientific questions, but it will also help shift their attitudes towards science in a positive direction.

• Korean Journal of Heritage: History & Science
• /
• v.49 no.1
• /
• pp.100-119
• /
• 2016

The concept of "original form" and the principle of "maintaining the original form" take center stage in conservation, management, and promotion of the domestic heritage. Introduced in the 20th century, there were little discussion or deliberation about the concept of "original form" therefore it remains a vague and somewhat abstract notion subject to individual interpretation. Without a specified practical meaning, "maintaining the original form" became the fundamental principle for heritage conservation and management in the 1999 version of the Cultural Heritage Protection Act, engendering difficulties in applying the principle in practice. Conceived as an important first step toward resolving the issues stemming from the indistinct concept of "original form," this paper explores the process through which the concept was introduced to Korea and then established and developed as a legal principle for heritage conservation, management, and promotion. While the examination of the related documents and various cases shows that the development of the concept of "original form" has centered on specific periods and architectural styles, this essay explicates that the notion "original form" is commonly used as a term referring to the form at the earliest possible temporality. It also explains that this view emanates from perceiving heritages not as multivalent objects, but as a material object that exclusively carries aesthetic and, more importantly, historical value, and that comes from the history awareness of the times. This essay suggests that the concept "original form" should be reestablished with full consideration of the diverse values of heritage and diverse forms through which heritage can be expressed. After reviewing the feasibility and practicality of the concept a set of concrete guidelines should be presented for application in practice.

• The Korean Journal of Archival Studies
• /
• no.45
• /
• pp.219-253
• /
• 2015

The Records Management System in Japan has been developed to a comprehensive and unitary records management system based on the records life-cycle principle from the enactment of 'the Public Records and Archives Management Act' in 2009 and its implementation in April, 2011. The scope of objects has also been extended to documents of independent administrative institutions and specific confidential documents on diplomacy and defense. In addition, a series of Electronic Documents Management Systems have been built for the transfer of electronic records to the National Archives of Japan, which is called the Electronic Records Archives of Japan, in connection with the records and archives management systems covering creation, management, transfer, preservation, and use of electronic records. This paper deals with the core contents and characteristics of the records management system of Japan, focusing on the operational structure of the records and archives management law and electronic documents management. Firstly, The Cabinet Office and professional groups in records and archives management started to work on reformation of the records management system from 2003 and resulted in enactment of the Public Records and Archives Management Act in 2009. In that sense, the Public Records and Archives Management Act can be evaluated as a result of constant activities of the records management community in Japan for realization of accountabilities of government agencies to the general public. Secondly, the Public Records Management Act of Japan has a coherent multi-layer structure from the law, enforcement ordinances, guidelines, and to institutional documents management regulations in the operational system. This is a systematic structure for providing practical business units of each administrative agency with detailed standards on the basis of guidelines and making them to prepare their own specific application standards related to their unique businesses. Unlike the past, the National Archives of Japan became to be able to identify specific historial documents which should be transferred to the archives by selecting important historical records as early as possible after creating and receiving them in each institution through the retention schedule. Thirdly, Japan started to operate a system in regard to electronic records transfer and preservation in 2011. In order to prepare for it, each administrative agency has used EDMS in creation and management of electronic records. A Guideline for the Standard Format and Media released by the Cabinet Office in 2010 is also for the transfer of electronic records to the Electronic Records Archives of Japan. In future, it is necessary to conduct further studies on activities of the records and archives management community in Japan, relating to long-term preservation and use of electronic records.

• Economic and Environmental Geology
• /
• v.54 no.2
• /
• pp.177-186
• /
• 2021

For disaster management and mitigation of earthquakes in Korea Peninsula, active fault investigation has been conducted for the past 5 years. In particular, investigation of sediment-covered active faults integrates geomorphological analysis on airborne LiDAR data, surface geological survey, and geophysical exploration, and unearths subsurface active faults by trench survey. However, the fault traces revealed by trench surveys are only available for investigation during a limited time and restored to the previous condition. Thus, the geological data describing the fault trench sites remain as the qualitative data in terms of research articles and reports. To extend the limitations due to temporal nature of geological studies, we utilized a terrestrial LiDAR to produce 3D point clouds for the fault trench sites and restored them in a digital space. The terrestrial LiDAR scanning was conducted at two trench sites located near the Yangsan Fault and acquired amplitude and reflectance from the surveyed area as well as color information by combining photogrammetry with the LiDAR system. The scanned data were merged to form the 3D point clouds having the average geometric error of 0.003 m, which exhibited the sufficient accuracy to restore the details of the surveyed trench sites. However, we found more post-processing on the scanned data would be necessary because the amplitudes and reflectances of the point clouds varied depending on the scan positions and the colors of the trench surfaces were captured differently depending on the light exposures available at the time. Such point clouds are pretty large in size and visualized through a limited set of softwares, which limits data sharing among researchers. As an alternative, we suggested Potree, an open-source web-based platform, to visualize the point clouds of the trench sites. In this study, as a result, we identified that terrestrial LiDAR data can be practical to increase reproducibility of geological field studies and easily accessible by researchers and students in Earth Sciences.

• Korean Journal of Heritage: History & Science
• /
• v.53 no.4
• /
• pp.198-215
• /
• 2020

Official development assistance refers to assistance provided by governments and other public institutions in donor countries, aimed at promoting economic development and social welfare in developing countries. The purpose of this research is to examine the construction process of the "Myanmar Cultural Heritage Management System" that is underway as part of the ODA project to strengthen cultural and artistic capabilities and analyze the achievements and challenges of the Digital Cultural Heritage ODA. The digital cultural heritage management system is intended to achieve the permanent preservation and sustainable utilization of tangible and intangible cultural heritage materials. Cultural heritage can be stored in digital archives, newly approached using computer analysis technology, and information can be used in multiple dimensions. First, the Digital Cultural Heritage ODA was able to permanently preserve cultural heritage content that urgently needed digitalization by overcoming and documenting the "risk" associated with cultural heritage under threat of being extinguished, damaged, degraded, or distorted in Myanmar. Second, information on Myanmar's cultural heritage can be systematically managed and used in many ways through linkages between materials. Third, cultural maps can be implemented that are based on accurate geographical location information as to where cultural heritage is located or inherited. Various items of cultural heritage were collectively and intensively visualized to maximize utility and convenience for academic, policy, and practical purposes. Fourth, we were able to overcome the one-sided limitations of cultural ODA in relations between donor and recipient countries. Fifth, the capacity building program run by officials in charge of the beneficiary country, which could be the most important form of sustainable development in the cultural ODA, was operated together. Sixth, there is an implication that it is an ODA that can be relatively smooth and non-face-to-face in nature, without requiring the movement of manpower between countries during the current global pandemic. However, the following tasks remain to be solved through active discussion and deliberation in the future. First, the content of the data uploaded to the system should be verified. Second, to preserve digital cultural heritage, it must be protected from various threats. For example, it is necessary to train local experts to prepare for errors caused by computer viruses, stored data, or operating systems. Third, due to the nature of the rapidly changing environment of computer technology, measures should also be discussed to address the problems that tend to follow when new versions and programs are developed after the end of the ODA project, or when developers have not continued to manage their programs. Fourth, since the classification system criteria and decisions regarding whether the data will be disclosed or not are set according to Myanmar's political judgment, it is necessary to let the beneficiary country understand the ultimate purpose of the cultural ODA project.