• Journal of Korean Society of Forest Science
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• v.79 no.4
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• pp.413-418
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• 1990

Since 1945, the periodical reforestation projects considered as the fundamental apparatus of the forest policy of the Government have been continuously carried out during last 40 years in Korea. As a result, some of the forests are ready to be harvested, especially in well-managed plantations as well as in the natural forests. This requires to pay more attention to harvesting the timber rather than planting trees. At the present, such timber harvesting operations such as cutting, felling, bucking, and skidding and yarding, particularly yarding operations in mountain areas with harsh terrains are in the most cases depend upon man power. However, the yarding operations should be more mechanized in the near future in Korea mainly because of the high cost of labour couppled with the lack of labour in forested areas. The Forest Work Training Center attached to the Forest Administration imported and tested the smallsized cable crane(K-300) with movable tower. The result of economic analysis of the yarding operation expenditures shows that the cable crane yarding costs more than the man yarding at the present time. As the labour cost will gradually increase and the efficiency of machine operation will improve, the results of the study indicates that the yarding operation by cable crane will be more cost-effective in the future.

• Journal of the Korean GEO-environmental Society
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• v.17 no.5
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• pp.37-46
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• 2016

In order to determine the variability of environmental characteristics of lightweight air-foamed soil using marine clay according to freezing-thawing and soaking conditions, unconfined compressive strength of the lightweight air-foamed soil samples made by changing the amount of cement under curing conditions of outdoor low temperature, underground or indoor wetting were observed. Compressive strength was not increased under freezing-thawing (temperature range of $-9.1^{\circ}C{\sim}17.2^{\circ}C$) regardless of the amount of cement but the more cement using, it was increased rapidly by underground curing conditions within 30 cm beneath ground level. Therefore, it is necessary to install insulation layer cutting off exterior cold air after construction of lightweight air-foamed soil in condition of freezing-thawing. Bulk density was increased too small under the long-time soaking condition, it tended to decrease rapidly when samples were dried up and had below 6% of water contents. But variability of compressive strength and bulk density was very small for preventing drying and keeping its wet state. The lightweight air-foamed soil that installed beneath ground water level or covered by soil can be evaluated as a long-term reliable construction material.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.37 no.2
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• pp.11-19
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• 2019

The study was done to analyze the records of planting time of Gwangneung needle firs referring to the historical literatures, the Annals of Joseon Dynasty(朝鮮王朝實錄), Seungjeongwonilgi(承政院日記: Journal of the Royal Secretariat). Bibyeonsadeungnok(備邊司謄錄: Records of the Bibyeonsa Defense Council, a government agency during the Joseon Dynasty), Ilseongnok(日省錄: Journal on Dynasty affairs of the kings in the 36th year of Youngjo to 1910) to lay the historical ground for needle firs in Gwangneung. The following results were derived from previous research, Report on Gwangneung Forest Ecosystem, and overlaid fir tree rings. The research findings are as follow. First, since the system of making the grave is the most conservative system, the planting during the Gwangneung construction would have been preceded by precedent. Second, the problem of cutting the tree in the late Joseon Dynasty became serious. It is published the Law of Muo In the 22nd year of Jeongjo, and then planted trees regularly in spring and autumn. Third, the Law of Muo was preserved for 31 years during the reign of King Gojong, and the type of specific tree, the number of trees, from the 22nd year until the 25th year of King Gojong, four years of fir trees were planted in Gwangneung, and Gwangneung was the only place where korean pine trees were planted. Fourth, it was possible to identify the age of the tree through fallen fir tree rings, and the period of planting fir trees growing in the existing mausoleum is judged to be the equivalent year of King Gojong's reign from the 10th year of King Cheoljong's reign.

• Journal of Technology Innovation
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• v.27 no.1
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• pp.45-77
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• 2019

The balance between exploration for new possibility and exploitation for existing certainty is an important issue in strategy, innovation, R&D as well as organization learning. Among the convergence trends of technologies, many firms seek to have the wider technological knowledge assets and the deeper technology capabilities for the sustainable competitive advantage at the same time. While firms plan technology portfolio strategies, they should consider the attribute of the technology. Nanotechnology, a cutting-edge technology, is a general purpose technology, unlike conventional product-oriented technologies. This empirical study was focused on how multi-national firms' exploration and exploitation strategies for nanotechnology affect their innovative and financial performance. It uses multiple regression analysis on panel data. This result shows that the more diversified and specialized nanotechnology as platform technology is positively related to their innovative and financial performance, unlike the research results for product-oriented technologies. In addition, exploratory innovation is more effective to firm performance than exploitation. This implies how global firms can manage effectively platform technology strategies under the constraints of resources.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.569-573
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• 2018

Music is composed of the sound of many instruments. Among them, the sound of the human voice naturally stands out to us and immediately connects with the listener. However, A lot of different steps go into perfectly mixing a vocal, but I'm going to focus on the most important step, equalization. In this paper, starting with the concept and the type of EQ for the requirements associated with the EQ's work and will know about when and how to use subtractive EQ, additive EQ during the recording and mixing process. EQ is one if the most important tools for mixing, especially when dealing with vocals. The control that EQ's offer allows you work, boosting and cutting to fit the vocal perfectly into the mix. The key to get a professional sounding vocal every time is to always keep in mind what you're trying to achieve stylistically and for it, using reference track is very effective. In addition to EQing, there are a variety of complex working steps such as compression, reverb, chorus, delay, adjusted for the effects of the work and harmonies of backing vocals and that are also very important task. The work of EQing is the beginning of the mixing process, among other things, need to be a detailed work throughout the consideration of the above points to its importance is greater relationship.

• Journal of the Korean Wood Science and Technology
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• v.49 no.6
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• pp.574-590
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• 2021

International efforts to prevent illegally logged wood are expanding around the world. The "Legal Wood Trade Promotion System" was enacted in Korea in 2019 to strengthen the legal import and distribution of commercial wood in Korea. Since then, this system has promoted and ensured that the imported wood and wood products are legal with respect to the country of origin, wood species, and harvested area. As verification methods, DNA analysis technology and anatomical analysis using a microscope are mainly used in conjunction. Therefore, in this study, wood species of plywood were identified by analyzing the anatomical characteristics of various wood products for the first time. Douglas fir (Pseudotsuga menziesii (Mirb.) Franco.) and larch (Larix kaempferi (Lamb.) Carriere) plywoods (7, 9 ply) were obtained from four companies that supply plywood in Korea. After cutting each company's plywood to a size of about 1 cm³, the layers from top to bottom were separated into single layers, and three sections were observed using an optical microscope. The results revealed that the plywood was composed of a mixture of softwood and hardwood wood species, pine wood species, poplar wood species, or a mixture of larch and pine wood species. Identification of wood species using microscopy is important and can enable the scientific analysis and verification of various wood products, including plywood, imported from countries where the likelihood of indiscriminate distribution of illegal wood and illegal logging is high.

• Journal of Korea Entertainment Industry Association
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• v.15 no.1
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• pp.53-62
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• 2021

After the first to present projected moving pictures to audiences, the film industry has been reshaping along with technological advancements. Through the full-scale introduction of visual effects-oriented post-production and digital technologies in the film-making process, the film industry has not only undergone significant changes in the production, but is also embracing the cutting edge technologies broadly and expanding the scope of industry. Not long after the change to digital cinema, the concept of artificial intelligence, first known at the Dartmouth summer research project in 1956, before the digitalization of film, is expected to bring about a big transformation in the film industry once again. Large volume of clear digital data from digital film-making makes easy to apply recent artificial intelligence technologies represented by machine learning and deep learning. The use of artificial intelligence techniques is prominent around major visual effects studios due to automate many laborious, time-consuming tasks currently performed by artists. This study aims to predict how artificial intelligence technology will change the film industry in the future through analysis of visual effects production cases using artificial intelligence technology as a production tool and to discuss the industrial potential of artificial intelligence as visual effects technology.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.2
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• pp.363-368
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• 2021

Ship engine rooms have improved automation systems owing to the advancement of technology. However, there are many variables at sea, such as wind, waves, vibration, and equipment aging, which cause loosening, cutting, and leakage, which are not measured by automated systems. There are cases in which only one engineer is available for patrolling. This entails many risk factors in the engine room, where rotating equipment is operating at high temperature and high pressure. When the engineer patrols, he uses his five senses, with particular high dependence on vision. We hereby present a preliminary study to implement an engine-room patrol robot that detects and informs the machine room while a robot patrols the engine room. Images of ship engine-room equipment were classified using a convolutional neural network (CNN). After constructing the image dataset of the ship engine room, the network was trained with a pre-trained CNN model. Classification performance of the trained model showed high reproducibility. Images were visualized with a class activation map. Although it cannot be generalized because the amount of data was limited, it is thought that if the data of each ship were learned through transfer learning, a model suitable for the characteristics of each ship could be constructed with little time and cost expenditure.

• Clean Technology
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• v.28 no.4
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• pp.323-330
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• 2022

Microfluidic paper-based analytical devices (μPADs) have recently been in the spotlight for their applicability in point-of-care diagnostics and environmental material detection. This study presents a double-sided printing method for fabricating 3D-μPADs, providing simple and cost effective metal ion detection. The design of the 3D-μPAD was made into an acryl stamp by laser cutting and then coating it with a thin layer of PDMS using the spin-coating method. This fabricated stamp was used to form the 3D structure of the hydrophobic barrier through a double-sided contact printing method. The fabrication of the 3D hydrophobic barrier within a single sheet was optimized by controlling the spin-coating rate, reagent ratio and contacting time. The optimal conditions were found by analyzing the area change of the PDMS hydrophobic barrier and hydrophilic channel using ink with chromatography paper. Using the fabricated 3D-μPAD under optimized conditions, Ni²⁺, Cu²⁺, Hg²⁺, and pH were detected at different concentrations and displayed with color intensity in grayscale for quantitative analysis using ImageJ. This study demonstrated that a 3D-μPAD biosensor can be applied to detect metal ions without special analysis equipment. This 3D-μPAD provides a highly portable and rapid on-site monitoring platform for detecting multiple heavy metal ions with extremely high repeatability, which is useful for resource-limited areas and developing countries.

• Journal of Dental Rehabilitation and Applied Science
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• v.38 no.3
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• pp.127-137
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• 2022

Zirconia is fabricated through various processes. Each element in fabricating process can affect the physical properties of the definitive prosthesis. In particular, both the milling process and the sintering process can affect the final integrity of the zirconia prosthesis. Most of the milling machines adopt the ultra-precision 5-axis machining method, and the results vary depending on which milling method was used and how the milling equipment was managed. Milling blocks are selected according to cutting efficiency and aesthetic reproducibility. The sintering method can affect the grain growth and optical properties, and an accurate evaluation can be made only with additional research on the recent speed sintering procedure. Not only the sintering temperature but also the temperature holding time can affect the quality of definitive prosthesis.