• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.6
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• pp.21-31
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• 2020

This study analyzed the spatio-temporal change pattern of greenhouse areas for Sangnam-myeon and Samrangjin-eup of Miryang-si in Gyeongnam, which is one of major greenhouse area. First, in order to overcome the lack of statistical data of the distribution of greenhouses, aerial and satellite images were interpreted from 1987 to 2018, and the spatial distribution of the greenhouse parcels which has continuously increased was mapped based on the digital cadastral map. Next, through the emerging hot spot tool in ArcGIS Desktop, the spatio-temporal change in transition from open-field to greenhouse cultivation was classified into 9 clusters. About 67.7% of the target area was categorized as a hot spot, and the pattern of New hot spot, which were recently converted to greenhouse parcels, covered about 34.1%. While, about 11.3% of parcels were expected to keep the existing open-field cultivation practice for a while. Overall, the greenhouse parcels have been densely developed along a river and were lately expanding even to the far neighbor. It implied that, in the future, the competition of water intake among farms would be more serious and the environmental responsibility in consideration of water quality as well as quantity would be getting strengthened due to increasing pollution loads and river intake.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.11
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• pp.148-154
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• 2001

Drilling is one of the most important operations in machining industry and usually the most efficient and economical method of cutting a hole in metal. From automobile parts to aircraft components, almost every manufactured product requires that holes are to be drilled for the purpose of assembly, creation of fluid passages, and so on. It is therefore desirable to monitor drill wear and hole quality changes during the hole drilling process. One important aspect in controlling the drilling process is monitoring drill wear status. A drill-wear monitoring system provides information about drill status. With the information, optimum planning for tool change is possible. And drill-wear monitoring system in needed to evaluated drilled hole quality and the wear of drill. Accordingly, this paper deals with an on-line drill wear monitoring system of the detection of tool wear with the computer vision and the area of the drill flank wear is analyzed quantitatively by the system.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.6
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• pp.1561-1566
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• 2012

Moxa cautery has long been used(among the public) due to its widespread efficacy with few side effects, and is still in use for a variety of purposes. However, conventional indirect moxa cautery accompanied with some problems such as smoke from its combustion and ashes which are difficult to clean. As parts of effects to deal with such problems, this research conducted a survey while referring to a variety of relevant documents. In the survey, 80% of respondents said that their current moxa tools are inconvenient to use. Many of them pointed out smoke, hot temperature problem, and the difficulty of fixing the tool as major sources of inconveniences in using moxa cautery.

• Biomolecules & Therapeutics
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• v.5 no.1
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• pp.8-11
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• 1997

The odor theory (기미론) has been defined as the Nature (기) and the Taste(미) of traditional herbal medicine to find the logic in treatment of various diseases by them. There is a strong possibility these Na1ures of the drug can be categorized according to yin (음) and yang (음). There is a neutral Nature which does not fit into one of these four categories. To understand the Natures of traditional herbal drugs in modern scientific approaches, changes in rectal temperature of rats have been measured at 0,30, 60, 90 min after a 10 g/Kg oral administration each of 34 different drugs. Following the classification of the four Natures of drugs, only the temperatures of warm group at 30, 60, and 90 min were elevated significantly from the control and the rest groups. Following a modified classification of 3 groups such as cold and cool, warm and hot, and neutral Nature, changes in temperatures after administration of Hot and Warm drugs were also increased significantly from the control (P<0.01). Thus, the measurement of rectal temperature can be a tool to define the Nature (기) of traditional herbal drugs, but the modified classification is another way to do.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.9
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• pp.82-88
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• 2001

In order to fulfil the requirements of the various performance profiles of ceramic cutting tools, six different SiC-based ceramics have been fabricated by hot-pressing (SiC--${Si}_3 {N}_4$composites) or by hot-pressing and subsequent annealing (monolithic SiC and SiC-TiC composites). Correlation between the annealing time and the corresponding microstructure and the mechanical properties of resulting ceramics have been investigated. The grain size of both ${Si}_3 {N}_4$and SiC in SiC-${Si}_3 {N}_4$composites increased with the annealing time. Monolithic SiC has the highest hardness, SiC-TiC composite the highest toughness, and the SiC-${Si}_3 {N}_4$composite the highest strength among the ceramics investigated. The hardness of SiC-${Si}_3 {N}_4$composites was relatively independent of the grain size, but dependent on the sintered density. The cutting performance of the newly developed SiC-based ceramic cutting tools will be described in Part 2 of this paper.

• Journal of Korea Foundry Society
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• v.26 no.5
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• pp.227-231
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• 2006

Liquid formability of bulk amorphous alloys is known to be very poor due to their high viscosity comparing with conventional metallic materials. It is important to have the fabricating technology of bulk amorphous alloys in order to make the components with complicated shape. Liquid formability includes the mold cavity filling ability and the hot tear(crack) resistance during solidification. A mold made of a commercial tool steel for the formability test was designed. Melting was performed by the arc melting furnace with melting capacity of 200 g in an argon atmosphere. Liquid formability and glass forming ability of Cu base and Ni base bulk amorphous alloys were measured and evaluated. Mold filling ability of Ni-Zr-Ti-Si-Sn alloy was better than that of Cu-Ni-Zr-Ti alloy, however the reverse is the hot tear resistance. Bulk amorphous alloy is very susceptible to crack if partial crystallization occurs during solidification. Crack resistance was thought to be closely related with the glass forming ability.

• Korean Journal of Materials Research
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• v.10 no.8
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• pp.532-539
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• 2000

Co-0.5C-(15~20)Cr-20Ni-8W-(2~7)Fe alloy bond in diamond-impregnated abrasive tool was synthesized by ball-milling and mechanical alloying process. When the powders were mechanical alloyed for 6h, micro-welding in most metal powders was observed irrespective of addition of stearic acid. Without stearic acid in metal powders, partial-ly coarse powders were obtained, which could be unfaverable to the densification of composite of composite powders. The hot-pressed compacts showed rupture strength of 1100MPa and hardness of about $46H_{RC}$, respectively.

• Nuclear Engineering and Technology
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• v.33 no.2
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• pp.209-224
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• 2001

The SSC-K system analysis code is under development at the Korea Atomic Energy Research Institute (KAERI) as a part of the KALIMER project. The SSC-K code is being used as the principal tool for analyzing a variety of off-normal conditions or accidents of the preliminary KALIMER design. The SSC-K code features a multiple-channel core representation coupled with a point kinetics model with reactivity feedback. It provides a detailed, one-dimensional thermal-hydraulic simulation of the primary and secondary sodium coolant circuits, as well as the balance-of-plant steam/water circuit. Recently a two-dimensional hot pool model was incorporated into SSC-K for analysis of thermal stratification phenomena in the hot pool. In addition, SSC-K contains detailed models for the passive decay heat removal system and a generalized plant control system. The SSC-K code has also been applied to the computational engine for an interactive simulation of the KALIMER plant. This paper presents an overview of the recent activities concerned with SSC-K code model development This paper focuses on both descriptions of the newly adopted thermal hydraulic and neutronic models, and applications to KALIMER analyses for typical anticipated transients without scram.

• Journal of the Korean Solar Energy Society
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• v.23 no.3
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• pp.7-14
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• 2003

Absorption potential of desiccant solution significantly decreases after absorbing moisture from humid air, and a regeneration process requires a great amount of energy to recover absorption potential of desiccant solution. In an effort to develop an energy efficient regenerator, this study examines a regeneration process using hot air heated by solar radiation to recover absorption potential by evaporating moisture in liquid desiccant. More specifically, this study is aimed at finding the optimum operating condition of the regenerator by utilizing a well-established statistical tool, so-called response surface methodology(RSM), which may provide a functional relationship between independent and dependent variables. It is demonstrated that an optimization model to find the optimum operating condition can be obtained using the functional relationship between regeneration rate and affecting factors which is approximated on the basis experimental results.

• Journal of Korea Foundry Society
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• v.39 no.1
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• pp.1-6
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• 2019

During the casting process, it is possible to minimize shrinkage and blowholes by modifying the casting design. However, it is impossible to eliminate these factors completely. Therefore, mechanical design engineers apply a sufficient safety factor owing to the possibility of insufficient performances of the cast products. In this paper, prediction method of the fatigue life of cast products containing shrinkage is conducted by using CT (computed tomography) and the SSM (shape simplification method), and additional fatigue analyses are carried out. The analysis results are then compared to results from actual experiments on samples with shrinkage defects. It is found to be that the considering actual shrinkage in cast products by means of stress and fatigue analyses is more accurate and effective. It is also considered that the proposed hot spot method provides us a good tool to predict the fatigue lifes of cast product.