• Analytical Science and Technology
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• v.31 no.6
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• pp.240-246
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• 2018

The present study analyzed standard samples of three types of aluminum matrix certified reference materials (CRM) using GD-MS. Calibration curves were constructed for 13 elements (Mg, Si, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Sn, and Pb), with the slope representing the relative sensitivity factor (RSF). The x- and y-axes of the calibration curve represented ion beam ratio (IBR) and the authenticated value of the standard sample, respectively. In order to evaluate precision and linearity of the calibration curve, RSD and the coefficient of determination were calculated. Curve RSD for every element reflected high precision (within 10 %). For most elements, the coefficient of determination was ${\geq}0.99$, indicating excellent linearity. However, vanadium, nickel, and gallium curves exhibited relatively low linearity (0.90~0.95), likely due to their narrow concentration ranges. Standard RSF was calculated using the slope of the curve generated for three types of CRM. Despite vanadium, nickel, and gallium exhibiting low coefficients of determination, their standard RSF resembled that of the three types of CRM. Therefore, the RSF method may be used for element quantitation. Standard iron matrix samples were analyzed to verify the applicability of the aluminum matrix standard RSF, as well as to calculate the RSD-estimated error of the measured value relative to the actual standard value. Six elements (Al, Si, V, Cr, Mn, and Ni) exhibited an RSD of approximately 30 %, while the RSD of Cu was 77 %. In general, Cu isotopes are subject to interference: $^{63}Cu$ to $^{54}Fe^{2+}-^{36}Ar$ and $^{65}Cu$ to $^{56}Fe-Al^{3+}$ interference. Thus, the influence of these impurities may have contributed to the high RSD value observed for Cu. To reliably identify copper, the resolution should be set at ${\geq}8000$. However, high resolutions are inappropriate for analyzing trace elements, as it lowers ion permeability. In conclusion, quantitation of even relatively low amounts of six elements (Al, Si, V, Cr, Mn, and Ni) is possible using this method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.10
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• pp.1737-1743
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• 2006

OCR(On channel repeater) provides the high frequency reuse efficiency for allocating frequency bands to repeaters because the frequency of input and output signals of OCRs is the same. However the oscillation probability of OCRs is high due to the same input and output frequency. In order to prevent a repeater from oscillating, we must keep the antenna isolation higher than the gain of the repeater with a some margin. In this paper we simulated the effects of the amplitude, phase and time delay of feedback signals (m the characteristics of non-regeneration OCR. Simulation results show that the highest probability of oscillation is occurred when the gain of a repeater is the same value of the isolation. From the simulation results, we know that the phase of feedback signals can be adjusted to reduce the possibility of oscillation if a non-regeneration repeater has a narrow operation bandwidth or a signal bandwidth is narrow. As the time delay increases, the probability of oscillation and the fluctuation of gain over a certain frequency band increase also. The effects of the amplitude and phase of feedback signals on S/N of 8-VSB signal for generation and non-generation repeater were tested. The measured results show that the set-top can receive 8-VSB signal when the received signal power is $17{\sim}18dB$ higher than the noise power. When the isolation is almost same as the gain of the repeater, then the set-top can not receive 8-VSB signals due to the oscillation of the repeater. And the phase of feedback signals affects S/N at the output of the repeater when the isolation is $11.75{\sim}13.75dB$ larger than the gain of the repeater. In this case the set-top can not receive 8-VSB signal of at $48^{\circ}\;and\;347^{\circ}$ of the phase of feedback signals. However the phase of feedback signals can not affect the S/N of 8-VSB signals of the generation repeater because of the demodulation and modulation process of the generation repenter. The set-top can not receive 8-VSB signals when the amplitude of feedback signals is $12.6{\sim}13.6dB$ larger than the wanted signal power at the input port of the repeater. It's because that the amplitude of feedback signals saturates the front end of the repeater.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.7 no.1
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• pp.5-22
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• 1994

This paper attempts to define some general characteristics of the Abstracting Journals published in Korea as evidenced in those published during last ten years. This purpose is achieved by comparing the results of the two studies conducted by the author in 1984 and in 1994. Both studies were conducted to present the state of the art in the abstracting services in Korea. The major conclusions made in this paper are summarised as follows： (1) Researchers and professionals working in a small number of subject fields are benefited by the abstracting journals, which provide current-awareness services of recent achievements in research and development in Korea. Those in most of the fields have no abstracting journals of their own, and naturally they have no substantial abstract-ing services. Even many researchers and professionals in the fields that have some abstracting journals are not informed of research results in their fields because the abstracting journals are scattered in many narrow subjects and in many cases, the abstracting journals only cover publications in some specific forms and kinds. (2) Abstracting journals that cover more than two subject fields, which are supposed to be of more or less help to the researchers and professionals in the subject fields that have no abstracting journals published in their fields, have rapidly increased in number in the past ten years. Most of suh abstracting journals carry thesis and dissertation abstracts, and the rest, those of research papers published in specific places, in specific forms, by specific institutions, and of reports of research projects sponsored by specific foundations. These abstracting journals are not of the kind that comprehensively provide researchers in related fields with current awareness of publications of research results in Korea. (3) Most of the abstracting Journals existing in Korea are Published by institutions of higher education and research institutes, and the rest, by commercial publishers, industrial firms, libraries, information centres, government agencies, research foundations, learned societies, etc. Those which publish many titles are small in number and those publish one or two titles are large in number. The former is largely made up of institutions of higher education and research institutes. (4) The abstracting journals published in Korea are classified by type into those of dissertations, research papers, journal articles, patent specifications in that descending order. The fact that Master; and doctoral dissertation abstracts ate dominating in Korea is due to the irrational practice of publishing those abstracts at many different institutions. (5) Most of the abstracting journals existing in Korea are published by national or government-supported research institutes in order to publicise their own research outputs. Their coverage of literature is normally narrow, and naturally their value to users is limited. (6) Korean is the desirable language for the abstracting journals intended to be distributed within Korea. About half of the abstracting jornals published in Korea is printed in Korean and the other half, in foreign languages, and in Korean and in foreign languages together. All the abstracting journals in foreign languages are printed in English except one, which is printed in Japanese. (7) Some twenty per cent of the abstracting journals in Korea is published monthly, bimonthly, and quarterly. The others are published annually, biannually and irregularly. The latter may not function properly as a current-awareness tool due to long intervals between their issues. It is particularly undesirable that about half of the abstracting journals in Korea is published irregularly. Most of the abstracting journals published in Korea are distributed freely to individuals and institutions selected by the publishers. (8) The abstracting journals published by the use of computers increased drastically in the past ten years. The abstracting journals produced by the conventional type-setting method will possibly disappear in Korea in another ten years to come. Automation of the production of abstracting journals does not simply mean technical, economic improvement in publishing processes but availability of machine-readable databases that can be used for many other pur-poses, including generation of other bibliographical publications and provision of machine literature searching capabilities. Necessary steps should be taken for this important development immediately.

• Korean Journal of Weed Science
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• v.30 no.3
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• pp.191-198
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• 2010

The objective of this study was to find herbicidal compounds from seven different plant essential oils such as amyris (Amyris balsamifera), cajuput (Melaleuca cajeputi), geranium (Pelargonium graveolens), lavender (Lavendula spp.), mandarin (Citrus reticulata), pine (Pinus spp.) and rosemary (Rosmarius officinale), and determine their herbicidal activities. The in vitro herbicidal activity of cajuput essential oil was the highest among six essential oils ($GR_{50}$ value, $425{\mu}g\;g^{-1}$) and major chemical components in cajuput essential oil were eucalyptol (37.2%), ${\alpha}$-terpineol (11.6%), benzaldehyde (5.2%), linalool (4.1%), ${\alpha}$-pinene (2.5%) and ${\beta}$-pinene (2.4%), and their $GR_{50}$ values were 2,731, 500, 50, 372, 4,363, and $4,671{\mu}g\;g^{-1}$, respectively. Soil application of cajuput essential oil and benzaldehyde did not show any herbicidal activity at 80 kg $ha^{-1}$. When cajuput essential oil was applied to foliar at 80 kg $ha^{-1}$, narrow-leaved plants such as sorghum (Sorghum bicolar), barnyardgrass (Echinochloa crus-galli), and southern crabgrass (Digitaria ciliaris) were killed 100%, however, broad-leaved plants indian jointvetch (Aeschynomeme indica), velvet leaf (Abutilon theophrasti), cocklebur (Xanthium strumarium), Japanese morningglory (Calystegia japonica) were not killed, indicating the cajuput essential oil was effective to control narrow-leaved plants. Herbicidal activities of benzaldehyde at 80 kg $ha^{-1}$, to those plants were 20, 60 and 95%, respectively. Overall data showed that the herbicidal activity of cajuput essential oil was in part due to benzaldehyde.

• Journal of the Korean Society for Library and Information Science
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• v.24
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• pp.9-51
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• 1993

The purpose of this study is twofold: to investigate into general characteristics of the abstracting services in Korea and to discuss general directions of development of the abstracting services in the country. This study is designed to achieve the purpose by gathering and analysing data related to the abstracting journals published in the past ten years and by comparing the results with similar data gathered by the investigator in 1984. The major conclusions made in this study is summarised as follows. (1) Researchers and professionals working in limited numbers of subject fields are benefited by abstracting services of recent achievements in research and development in Korea. Those in most of the fields have essentially no abstracting services of such achievements. Even many researchers and professionals in the limited numbers of the fields that have some elementary abstracting services are not informed of research results in their fields because the abstracting journals are scattered in many narrow subjects and in many cases, the abstracting journals only cover publications in some specific forms and kinds. (2) Abstracting journals of general subjects, which are supposed to be of more or less help to the researchers in the subject fields that have no abstracting journals of their own, have rapidly increased in number in the past ten years. Most of such abstracting journals carry thesis and dissertation abstracts, and the rest those of research papers published in specific places, in specific forms, by specific institutes, and of reports of research projects sponsored by specific foundations. These abstracting journals are not of the kind that comprehensively provide general readers with current awareness of publications of research results in Korea. (3) Most of the abstracting journals existing in Korea are published by institutions of higher education and research institutes, and the rest by commercial publishers, industrial firms, libraries, information centers, government agencies, research foundations, learned societies, etc. Those which publish many titles are small in number and those publish one or two titles are large in number. The former is largely made up of institutions of higher education and research institutes. (4) Ten years ago, there was not a single publishing house that produced abstracting journals. Three commercial publishing houses now produce abstracting journals. As this change occurs, centers of excellence are founded and competitive elements are introduced in abstracting services. This change, in turn, is expected to improve quality of the other abstracting journals in Korea. (5) The abstracting journals published in Korea are classified by type into those of dissertations, research papers, journal articles, patent specifications in that descending order. The fact that Master's and doctoral dissertation abstracts are dominating in Korea is due to the irrational practice of publishing those abstracts at many institutions. (6) Most of the abstracting journals existing in Korea are published by national or government-supported research institutes in order to publicise their own research outputs. Their coverage of literature is normally narrow, and naturally their value to users is limited. (7) The abstracting journals published in Korea increased in number at the rate of $77.8-100\%$ every five years in the past twenty-five years. Most of the abstracting journals that ceased to be published during the period survived for two years. (8) Korean is the desirable language for the abstracting journals designed to be distributed within Korea. About half of the abstracting journals published in Korea is printed in Korean and the other half in foreign languages, and in Korean with foreign languages. All the abstracting journals in foreign languages are printed in English xcept one, which is printed in Japanese. (9) Some twenty percent of the abstracting journals in Korea is published monthly, bimonthly, and quarterly. Others are published annually, biannually, and irregularly. The latter may not function properly as a current-awareness tool due to long intervals between their issues. It is particularly undesirable that about half of the abstracting journals in Korea is published irregularly. Most of the abstracting journals published in Korea are distributed freely to individuals and institutions selected by the publishers. (10) The abstracting journals published by the use of computers increased drastically in the past ten years. The abstracting journals produced by the conventional type-setting method will probably disappear In Korea in another ten years to come. Automation of the production of abstracting journals does not simply mean technical, economic improvement of publishing processes but availability of machine-readable databases that can be used for other purposes, including the generation of other publications and the provision of machine literature searching capabilities. Necessary steps should be taken for this important development that is occurring in the abstracting services in Korea.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.2
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• pp.1-12
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• 2015

This study explores urban gardening and garden culture in residential area as an everydayness that has been overlooked during the modern period urbanization and investigates the meaning and value of urban gardening from the perspective of urban formations and growth in spontaneous urban residential area, Haebangchon. The result identified that urban gardening as a meaning of contemporary culture is a new clue to improving the urban physical environment and changing the lives and community network of residents. Haebangchon is one of the few remaining spontaneous habitations in Seoul, and was created as a temporary unlicensed shantytown in 1940s. It became the representative habitation for common people in downtown Seoul through the revitalization of the 60s and the local reform through self-sustaining redevelopment projects during the 70s through the 90s. This area still contains the image of times during the 50s to the 60s, the 70s to the 80s and present, with the percentage of long-term stay residents high. Within this context, the site is divided into third quarters, and the research undertaken by observation and investigation to determine characteristics of urban gardening as an everydayness. It can be said that urban gardening and garden culture in Haebangchon is a unique location culture that has accumulated in the crevices of the physical condition and culture of life. These places are an expression of resident's desires that seeking out nature and gardening as revealed in densely-populated areas and the grounds of practical acting and participating in care and cultivation. It forms a unique, indigenous local landscape as an accumulation of everyday life of residents. Urban gardens in detached home has retained the original function of the dwelling and the garden, or 'madang', and takes on the characteristic of public space through the sharing of a public nature as well as semi-private spatial characteristic. Also, urban gardens including small kitchen garden and flowerpots that appear in the narrow streets provide pleasure as a part of nature that blossoms in narrow alley and functions as a public garden for exchanging with neighbors by sharing produce. This paper provides the concept of redefining the relationship between the private-public area that occurs between outside spaces that are cut off in a modern city.

• Proceedings of the Korean Journal of Food and Nutrition Conference
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• 2001.12a
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• pp.39-74
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• 2001

The endeavors enhancing the grain quality of high-yielding japonica rice were steadily continued during 1980s∼1990s along with the self-sufficiency of rice production and the increasing demands of high-quality rices. During this time, considerably great, progress and success was obtained in development of high-quality japonica cultivars and qualify evaluation techniques including the elucidation of interrelationship between the physicochemical properties of rice grain and the physical or palatability components of cooked rice. In 1990s, some high-quality japonica rice caltivars and special rices adaptable for food processing such as large kernel, chalky endosperm aromatic and colored rices were developed and its objective preference and utility was also examined by a palatability meter, rapid-visco analyzer and texture analyzer. The water uptake rate and the maximum water absorption ratio showed significantly negative correlations with the K/Mg ratio and alkali digestion value(ADV) of milled rice. The rice materials showing the higher amount of hot water absorption exhibited the larger volume expansion of cooked rice. The harder rices with lower moisture content revealed the higher rate of water uptake at twenty minutes after soaking and the higher ratio of maximum water uptake under the room temperature condition. These water uptake characteristics were not associated with the protein and amylose contents of milled rice and the palatability of cooked rice. The water/rice ratio (in w/w basis) for optimum cooking was averaged to 1.52 in dry milled rices (12% wet basis) with varietal range from 1.45 to 1.61 and the expansion ratio of milled rice after proper boiling was average to 2.63(in v/v basis). The major physicochemical components of rice grain associated with the palatability of cooked rice were examined using japonica rice materials showing narrow varietal variation in grain size and shape, alkali digestibility, gel consistency, amylose and protein contents, but considerable difference in appearance and torture of cooked rice. The glossiness or gross palatability score of cooked rice were closely associated with the peak. hot paste and consistency viscosities of viscogram with year difference. The high-quality rice variety “Ilpumbyeo” showed less portion of amylose on the outer layer of milled rice grain and less and slower change in iodine blue value of extracted paste during twenty minutes of boiling. This highly palatable rice also exhibited very fine net structure in outer layer and fine-spongy and well-swollen shape of gelatinized starch granules in inner layer and core of cooked rice kernel compared with the poor palatable rice through image of scanning electronic mcroscope. Gross sensory score of cooked rice could be estimated by multiple linear regression formula, deduced from relationship between rice quality components mentioned above and eating quality of cooked rice, with high Probability of determination. The ${\alpha}$ -amylose-iodine method was adopted for checking the varietal difference in retrogradation of cooked rice. The rice cultivars revealing the relatively slow retrogradation in aged cooked rice were Ilpumbyeo, Chucheongbyeo, Sasanishiki, Jinbubyeo and Koshihikari. A Tongil-type rice, Taebaegbyeo, and a japonica cultivar, Seomjinbyeo, shelved the relatively fast deterioration of cooked rice. Generally, the better rice cultivars in eating quality of cooked rice showed less retrogiadation and much sponginess in cooled cooked rice. Also, the rice varieties exhibiting less retrogradation in cooled cooked rice revealed higher hot viscosity and lower cool viscosity of rice flour in amylogram. The sponginess of cooled cooked rice was closely associated with magnesium content and volume expansion of cooked rice. The hardness-changed ratio of cooked rice by cooling was negatively correlated with solids amount extracted during boiling and volume expansion of cooked rice. The major physicochemical properties of rice grain closely related to the palatability of cooked rice may be directly or indirectly associated with the retrogradation characteristics of cooked rice. The softer gel consistency and lower amylose content in milled rice revealed the higher ratio of popped rice and larger bulk density of popping. The stronger hardness of rice grain showed relatively higher ratio of popping and the more chalky or less translucent rice exhibited the lower ratio of intact popped brown rice. The potassium and magnesium contents of milled rice were negatively associated with gross score of noodle making mixed with wheat flour in half and the better rice for noodle making revealed relatively less amount of solid extraction during boiling. The more volume expansion of batters for making brown rice bread resulted the better loaf formation and more springiness in rice bread. The higher protein rices produced relatively the more moist white rice bread. The springiness of rice bread was also significantly correlated with high amylose content and hard gel consistency. The completely chalky and large gram rices showed better suitability for fermentation and brewing. Our breeding efforts on rice quality improvement for the future should focus on enhancement of palatability of cooked rice and marketing qualify as well as the diversification in morphological and physicochemical characteristics of rice grain for various value-added rice food processings.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.3
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• pp.215-220
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• 2008

This experiment was conducted to compare forage production and feed value of winter forage crops at the experimental field of Livestock Division, National Institute of Subtropical Agriculture from 2007 to 2008. The experiment was arranged in a randomized block design with three replications. The five winter forage crops used in this experiment were barely ('Youngyang' and 'Yuyeon'), oats ('Samhan' and 'Swan'), wheat ('Kumkang' and 'Woori'), triticale ('Shinyoung') and italian ryegrass ('Hwasan 101' and 'Florida-80'). The species having the fastest heading date was wheat (5th April) while the heading date of oats ('Samhan') was the latest as 28th April. The dry matter (DM) content of wheat was the highest among the five winter forage crops. Italian ryegrass ('Hwasan 101') showed the highest CP content by 11.2% and oats (Swan) showed the lowest content by 9.8%. Average acid detergent fiber (ADF) and neutral detergent fiber (NDF) content were 28.6 and 50.8% respectively. The five winter forage crops have narrow range of total nutrient digestibility (TDN) from 64.0% to 69.1%. Italian ryegrass ('Hwasan 101') showed the highest DM yield by 25,951 kg/ha, but the DM yield of barely and wheat low by 13,892 kg/ha ('Yuyeon') and 14,815 kg/ha ('Woori'), respectively. Italian ryegrass and oats have higher forage yield and feed value in Jeju. Also, oats has high grain and forage yield. The results demonstrated oats can cultivate as alternative winter forage crop for whole crop silage barely in Jeju.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.189-189
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• 2012

Lead sulfide (PbS) nanocrystal quantum dots (NQDs) are promising materials for various optoelectronic devices, especially solar cells, because of their tunability of the optical band-gap controlled by adjusting the diameter of NQDs. PbS is a IV-VI semiconductor enabling infrared-absorption and it can be synthesized using solution process methods. A wide choice of the diameter of PbS NQDs is also a benefit to achieve the quantum confinement regime due to its large Bohr exciton radius (20 nm). To exploit these desirable properties, many research groups have intensively studied to apply for the photovoltaic devices. There are several essential requirements to fabricate the efficient NQDs-based solar cell. First of all, highly confined PbS QDs should be synthesized resulting in a narrow peak with a small full width-half maximum value at the first exciton transition observed in UV-Vis absorbance and photoluminescence spectra. In other words, the size-uniformity of NQDs ought to secure under 5%. Second, PbS NQDs should be assembled carefully in order to enhance the electronic coupling between adjacent NQDs by controlling the inter-QDs distance. Finally, appropriate structure for the photovoltaic device is the key issue to extract the photo-generated carriers from light-absorbing layer in solar cell. In this step, workfunction and Fermi energy difference could be precisely considered for Schottky and hetero junction device, respectively. In this presentation, we introduce the strategy to obtain high performance solar cell fabricated using PbS NQDs below the size of the Bohr radius. The PbS NQDs with various diameters were synthesized using methods established by Hines with a few modifications. PbS NQDs solids were assembled using layer-by-layer spin-coating method. Subsequent ligand-exchange was carried out using 1,2-ethanedithiol (EDT) to reduce inter-NQDs distance. Finally, Schottky junction solar cells were fabricated on ITO-coated glass and 150 nm-thick Al was deposited on the top of PbS NQDs solids as a top electrode using thermal evaporation technique. To evaluate the solar cell performance, current-voltage (I-V) measurement were performed under AM 1.5G solar spectrum at 1 sun intensity. As a result, we could achieve the power conversion efficiency of 3.33% at Schottky junction solar cell. This result indicates that high performance solar cell is successfully fabricated by optimizing the all steps as mentioned above in this work.

• Korean Journal of Clinical Pharmacy
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• v.30 no.1
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• pp.36-43
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• 2020

Background: Tacrolimus, a calcineurin inhibitor, is an immunosuppressant used in post-transplantation maintenance therapy. The drug has a narrow therapeutic range and requires periodic therapeutic drug monitoring. Although many studies have reported the effects of intrapatient variability of tacrolimus on survival, rejection, and complications in renal transplant recipients, very few studies have reported these effects in liver transplant recipients. The purpose of this study was to evaluate the effect of intrapatient variability of tacrolimus on clinical outcomes after liver transplantation. Methods: Intrapatient variability was calculated using individual, averaged tacrolimus concentrations. Patients were divided into two groups according to their median variability value: high-variability and low-variability groups. The rate of deviation from the therapeutic range, incidence of acute rejection, post-transplant diabetes, incidence of infection, and estimated glomerular filtration rate (eGFR) after transplantation were compared between the groups. Results: Of the total patients (n=82), the high-variability group (n=41) exhibited significantly greater deviation from the therapeutic range (65.92% vs. 56.84%; p<0.001). There was no significant difference in acute rejection or post-transplantation diabetes incidence or eGFR; however, the number of infection in the first 6 months was significantly lower in the low-variability group (0.4 vs. 0.9 times; p=0.039). Multiple linear regression analysis showed that the number of infection significantly increased as intrapatient variability increased (p=0.015). Conclusion: High intrapatient variability in tacrolimus concentrations was strongly associated with an increased frequency of deviation from the suggested therapeutic range and an increased number of infection.