• Geophysics and Geophysical Exploration
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• v.2 no.2
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• pp.104-111
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• 1999

As a practical developing step of electromagnetic (EM) tomography technique, we quantitatively analyzed the effects of borehole fluid and casing on the borehole EM responses. The EM response turns out to have nothing to do with the property of the borehole fluid except in the close vicinity of the transmitter, which shows the wide perspective of the application of borehole EM. Single-hole responses in the presence of the steel casing throughly reflect those of the casing itself since its extremely high induction number or shallow skin depth. EM responses through steel casing do show the information of the host medium. In the near field region which corresponds to low frequency or the vicinity of the borehole, however, we can not separate the signal containing the information of the host from that of casing. Otherwise, the severe attenuation of energy in the casing at high frequencies renders the signal undetectable. The optimum frequency is, therefore, to be chosen to extract the information of the host considering both the property of the casing and the skin depth of the medium and the practical technique to determine the casing property through single-hole measurements is required.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.2 no.4
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• pp.135-151
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• 2007

A 5 days working system and a 6 days working system will be put in force at a food service consumption behavior of company workers. As a 5 days working system have adopted company, which the number of employee is more than 50, from July 1, 2007. The purpose of this paper is to study the In food service consumption behavior of company workers. There is no doubt that it is only way of surviving In current society to analyze the change of social situation and actively cope with the development. Especially, in the field of restaurant industries, they have to be equipped with a great store of experience and skill, theory and practical business, pertinent and rapid disposal. Consequently, it is very important to know the objective and practical knowledge for the restaurant industries trend by having a through grasp of the need of consumer and their propensity to consume. In order to study motives of eating-out and restaurants selection, office workers, who live in the national capital region, are interviewed. The period of interview is from Oct 1 to Nov 20, 2007. According to the result of interview, The most workers prefer to eating-out on week with family and friends. But family is eating-out the more preference to weekend compare to friends. And it is deduced that restaurant near tourist resorts or outside the city rather than in downtown will be prosperous with this result. That is to say, workers go out to eat delicious food regardless of traffic problem and distance, with the increase of national income and the car holding. This paper is worthy of notice in terms of trying to find the relevance between the working system and the restaurant industries development. In after research, I expect the more synthetic and deeper study should be made though the more technical methods.

• Korean journal of applied entomology
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• v.48 no.4
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• pp.423-429
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• 2009

Characteristics of habitat alteration and post-embryonic development of Paratlanticus ussuriensis were investigated in the mountain region of Bitanri, Yeongdong county, Chungcheongbuk-do from 2007 to 2009. Overwintered eggs under the ground in the hillside were hatched from late March to early April. The soil temperature during this season was $7{\sim}14^{\circ}C$. Young nymphs lived mainly at the hillside by eating oak tree leaves but the 3rd or 4th instars switched their habitat to orchards near the hillside in early May, which is the time for sprouting of peach leaves. Old nymphs developed into the adult stage at the orchards in late May and moved back to the hillside in late June. Duration of post-embryonic development from the first instar nymph to adult was 49.2 days after 7 moltings at $25^{\circ}C$. Female adults collected from the field had long ovipositor (26.2 mm) and were slightly longer in the body length, hind femur, tegmen and pronotum than those of males.

• Geophysics and Geophysical Exploration
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• v.4 no.4
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• pp.124-132
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• 2001

Electrical resistivity survey has been conducted for delineating geological fault structure in Kaekok-ri near Kyungju. In general, electrical resistivity survey has an advantage of searching buried faults and its traces compared with other geophysical survey methods. Distribution of electrical conductivity in the ground is influenced by the ratio of pores, groundwater and clay minerals. These properties are evidenced indirectly to explain for weathering condition, faults and fracture Bones. Thus the electrical resistivity survey can be an effective method to find buried faults. We have carried out two dimensional (2-D) interpretation by means of smoothness-constrained least-squares and finite element method. Field data used in this paper was acquired at Kaekok-ri, Wuedong-eup, Kyungju-si, where is Ulsan Fault and is close to the region in which debatable quaternary fault traces were found recently. The dipole-dipole array resistivity survey which could show the 2-D subsurface electrical resistivity structure, was carried out in the area with three lines. The results showed good property of fault, fracture zone and fault traces which we estimated were congruous with the results. Through this study, 2-D electrical resistivity survey interpretation for fault is useful to apply.

• Journal of the Korean Society for Nondestructive Testing
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• v.16 no.3
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• pp.162-173
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• 1996

Dry magnetic particle inspection(MPI) was performed to detect the surface defects of steel ingot cast billets. Magnetic properties of several materials were characterized by the measurement of the B-H hysteresis curve. The inspection results were evaluated in terms of the magnetizing current, temperature, and the amount of magnetic particles applied to billets. Magnetic flux leakage near the defect site of interest was measured and compared with the results of calculation by the finite element method in the case of direct magnetizing current. Direct and alternating magnetizing currents for materials were deduced by the comparison of the inspections. Results of the magnetic particle inspection by direct magnetizing current were compared with those of finite element method calculations, which were verified by measuring magnetic leakage flux above the surface and the surface defects of the material. For square rods, due to the geometrical effect, the magnetic flux density at the edges along the length of the rods was about 30% of that at the center of rod face for a sufficiently large direct magnetizing current, while it was about 70% for an alternating magnetizing current. Thus, an alternating magnetizing current generates rather uniform magnetic flux density over the rods, except for the region on the face across about 10 mm from the edge. The attraction of the magnetic particle by the magnetic leakage field was nearly independent of the surface temperature of the billets up to $150^{\circ}C$. However, the temperature should have been limited below $60^{\circ}C$ for an effective fixing of gathered magnetic particles to the billet surface using methylene chloride. We also found that the amount of applied magnetic particles tremendously affected the detection capability.

• Magazine of the Korean Society of Agricultural Engineers
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• v.24 no.1
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• pp.31-43
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• 1982

Engineering phase of dairy housing systems has close connection with the milk produc- tivity of dairy cattle, the quality of milk, extension of dairy production systems, labor- saving in management of dairy cattle and the like. Moreover, the rate of investment of dairy housing facilities is of relatively high level, However, there has been almost no research effort for the improvement of engineering aspects of dairy housing systems in Korea. The purpose of this study is to find out general engineering problems and to recomm- end the improvement in dairy housing systems in Korea. Field survey by means of questionaire, direct measurements, taking pictures and sketching was conducted to get necessary information for the study. Kyung-ki Do region was firstly chosen for sampling area since it has included more than half of the number of dairy farms of the whole country. The results obtained are summarized as follows: 1. In overall dairy farm layout, the dwellings of workers were ignored in the light of sanitary environment 2. The layout of stalls in a dairy barn belongs mostly to the type of double-row face-out, which is compatible with the emphasis of manure disposal activities. 3. While the width and length of stalls were sufficiently close to the standard dimension, the width of mangers was much less than the standard dimension. 4. The width and depth of manure gutters and the width of working alleys were much. less than the standard dimension. 5. The mooring equipment was mostly in the classes of chain or rope. The watering equipment was not facilitated independantly except the one cese of using watercup. 6. The bucket milkers with one or two bucket milkers with the capacity of two cattles. each were used as milking equipment in most dairy farms. 7. There were only few milk rooms independently spaced from other space, in which the arrangement of milking equipment was much less than the standard condition. 8. The lounging ground area was averaged to be sufficient for the activity of dairy herd. 9. Silos for silage used during winter consisted of mostly bunker silos, trench silos and underground vertical silos. Ordinary vertical silos were considered for the farmers to be inconvenient for the labor saving. 10. From the view point of heat conservation and moisture removal within the dairy barns, windows were not flexible for the easy ventilation and ceiling part was not adequate for temperatur maintenance. 11. Waste treatment and disposal systems were not provided with most dairy farms, therefore the livestock waste pollution problems would be serious in the near future.

• Proceedings of the Korea Crystallographic Association Conference
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• 2002.11a
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• pp.5-6
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• 2002

The new spectrometer for X-ray Induced Electron Emission Spectroscopy (XIEES) .has been recently developed in KRISS in collaboration with PTI (Russia). The spectrometer allows to perform research using the XAFS, SXAFS, XANES techniques (D.C.Koningsberger and R.Prins, 1988) as well as the number of techniques from XIEES field(L.A.Bakaleinikov et all, 1992). The experiments may be carried out with registration of transmitted through the sample x-rays (to investigate bulk samples) or/and total electron yield (TEY) from the sample surface that gives the high (down to several atomic mono-layers in soft x-ray region) near surface sensitivity. The combination of these methods together give the possibility to obtain a quantitative information on elemental composition, chemical state, atomic structure for powder samples and solids, including non-crystalline materials (the long range order is not required). The optical design of spectrometer is made according to Johannesson true focusing schematics and presented on the Fig.1. Five stepping motors are used to maintain the focusing condition during the photon energy scan (crystal angle, crystal position along rail, sample goniometer rail angle, sample goniometer position along rail and sample goniometer angle relatively of rail). All movements can be done independently and simultaneously that speeds up the setting of photon energy and allows the using of crystals with different Rowland radil. At present six curved crystals with different d-values and one flat synthetic multilayer are installed on revolver-type monochromator. This arrangement allows the wide range of x-rays from 100 eV up to 25 keV to be obtained. Another 4 stepping motors set exit slit width, sample angle, channeltron position and x-ray detector position. The differential pumping allows to unite vacuum chambers of spectrometer and x-ray generator avoiding the absorption of soft x-rays on Be foil of a window and in atmosphere. Another feature of vacuum system is separation of walls of vacuum chamber (which are deformed by the atmospheric pressure) from optical elements of spectrometer. This warrantees that the optical elements are precisely positioned. The detecting system of the spectrometer consists of two proportional counters, one scintillating detector and one channeltron detector. First proportional counter can be used as I/sub 0/-detector in transmission mode or by measuring the fluorescence from exit slit edge. The last installation can be used to measure the reference data (that is necessary in XANES measurements), in this case the reference sample is installed on slit knife edge. The second proportional counter measures the intensity of x-rays transmitted through the sample. The scintillating detector is used in the same way but on the air for the hard x-rays and for alignment purposes. Total electron yield from the sample is measured by channeltron. The spectrometer is fully controlled by special software that gives the high flexibility and reliability in carrying out of the experiments. Fig.2 and fig.3 present the typical XAFS spectra measured with spectrometer.

• Conservation Science in Museum
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• v.19
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• pp.19-40
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• 2018

Most stone monuments in Korea are made from the granitoids found extensively throughout the nation. To identify the provenance of the stone materials, this study carried out comprehensive analyses of the occurrence, physical properties, mineralogy, and chemical composition of Stupa for National Preceptor Wongong at Geodonsa Temple and Five-story Pagoda at Cheonsusa Temple, both located in the Gangwon region. Their features were compared with those of granite from Wonju City near the sites of the two monuments. Stupa for National Preceptor Wongong is composed purely of two-mica granite, whereas Five-story Pagoda was made from both two-mica and biotite granites. The occurrence and magnetic susceptibility of the two granite monuments generally coincide with those of granite from Wonju. When selecting materials for the restoration of stone monuments, it is deemed necessary to carry out a field survey on granite in areas adjacent to the locations of the stone monuments subject to restoration.

• Korean Journal of Plant Taxonomy
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• v.41 no.4
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• pp.429-439
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• 2011

We investigated the flora of Imja-do(Isl.), an island of the Shinan archipelago, located in Imja-myeon, Shinan-gun, Jollanamo-do and discussed the vascular plants found there. Twenty-four separate field trips (100days) were completed from August of 1997 to October of 2009. As a result, we identified the distribution of 526 taxa in Imja-do(Isl.), comprising 112 families, 331 genera, 463 species, 1 subspecies, 60 varieties, and 2 forms. There are a total of 78 taxa of floristic regional indicator plants and one taxon of level II endangered species, Millettia japonica, as designated by the Korean Ministry of the Environment. The floristic regional indicator plants are as follows; four taxa of level V such as Utricularia bifida, two taxa of level IV such as Cladium chinense, 14 taxa of level III such as Aletris spicata, three taxa of level II, and 55 taxa of level I. In addition, one endangered species (EN), Nymphoides coreana, five vulnerable species (VU),such as Ilex cornuta, and three near-threatened species (NT) such as Utricula riaracemosa, were found in the investigated area. The plants of Imja-do(Isl.) are classified into four types based on the plant geographical origin, as follows: 1) boreal plants advancing southward in a glacial period, 2) temperate plants spreading eastward from the Himalayas and China to Japan passing through the south coast of Korea, 3) subtropical plants, and 4) indigenously developed endemic species of the warm-temperate region of East Asia.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.37.3-38
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• 2016

Recent studies suggest that faint active galactic nuclei may be responsible for the reionization of the universe. Confirmation of this scenario requires spectroscopic identification of faint quasars ($M_{1450}$ > -24 mag) at z > 6, but only a very small number of such quasars have been spectroscopically identified so far. Here, we report the discovery of a faint quasar IMS J220417.92+011144.8 at z ~ 6 in a $12.5deg^2$ region of the SA22 field of the Infrared Medium-deep Survey (IMS). The spectrum of the quasar shows a sharp break at ${\sim}8443{\AA}$, with emission lines redshifted to $z=5.944{\pm}0.002$ and rest-frame ultraviolet continuum magnitude $M_{1450}=-23.59{\pm}0.10$ AB mag. The discovery of IMS J220417.92+011144.8 is consistent with the expected number of quasars at z ~6 estimated from quasar luminosity functions based on previous observations of spectroscopically identified low-luminosity quasars. This suggest that the number of $M_{1450}$ ~ -23 mag quasars at z ~ 6 may not be high enough to fully account for the reionization of the universe. In addition, our study demonstrates that faint quasars in the early universe can be identified effectively with a moderately wide and deep near-infrared survey such as the IMS.