• Research in Plant Disease
• /
• v.23 no.1
• /
• pp.49-55
• /
• 2017

The previous study showed that die-back of apple trees caused by soil-borne diseases was significantly high in the apple orchards in Chungbuk province. The correlation between dieback ratio and cultivation environment in apple orchards infected by soil-borne diseases was investigated in this study. The dieback ratio of five orchards diseased by violet root rot and five places infected by white root rot showed significantly positive correlation with Ca content and available $P_2O_5$ content in soil, respectively. Whereas, the dieback ratio of fourteen orchards diseased by Phytophthora root rot was not significant. Subgrouping of cultivation environment analysis showed that the slope degree of orchard and the number of fruit setting also affected the dieback ratio caused by violet root rot and Ca content in soil also affected the dieback ratio caused by white root rot. It showed that the slope degree, soil texture, Mg and Ca content affected the dieback ratio caused by Phytophthora root rot. These results can be applied to reduce die-back ratio by the modification cultivation environment for each soil-borne disease.

• Clinical and Experimental Pediatrics
• /
• v.45 no.4
• /
• pp.473-481
• /
• 2002

Purpose : Ascending cholangitis is the most common complication after Kasai operations. The aim of this study is to evaluate the therapeutic efficacy of cefotaxime as an empirical antibiotic on ascending cholangitis after Kasai operations. Methods : Thirty-nine episodes of cholangitis in twenty-nine children who underwent Kasai operations at Seoul National University Children's Hospital from January 1991 to December 2000 were included in this study. Empirical cefotaxime treatments were divided into three groups : cefotaxime and amikacin treatment group(CA group), cefotaxime and gentamicin treatment group(CG group) and cefotaxime treatment group(C group). A diagnosis of cholangitis was made on the basis of unexplained fever(>$38^{\circ}C$) and either development of acholic stool or elevation of serum total bilirubin (>1.5 mg/dL). Therapeutic efficacy was judged by elimination of fever up to 72 hours, 120 hours, and 168 hours after antibiotic treatment. Results : There were therapeutic responses in 51%(20/39) up to 72 hours after antibiotic treatment : 54%(13/24) in CA group, 43%(3/7) in CG group and 50%(4/8) in C group. There were therapeutic responses in 69%(27/39) up to 120 hours, in 79%(31/39) up to 168 hours and in 82%(32/39) up to 2 weeks. There were no differences in therapeutic efficacy among the three regimens. In 12 of 39 episodes, the etiologic pathogens including Escherichia coli and enterococcus were cultured from the blood. Conclusion : Cefotaxime can be tried as an initial antibiotic in Korean children with ascending cholangitis after Kasai operation prior to the identification of microorganism on culture. However, further evaluation of pathogen and its resistant strain to cefotaxime should be done.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.50 no.6
• /
• pp.1-14
• /
• 2022

To alleviate the urban heat island phenomenon, this study aims to quantitatively analyze the effects of neighborhood green spaces on the improvement of the thermal environment based on detailed scenarios of five types of green spaces, including parks, pocket parks, parking lot greening, roadside planting, and rooftop-wall greening. The ENVI-met 4.4.6v model, a microclimate simulation program, was used to analyze the effects of green spaces. As a result, it was found that the air temperature decreased as the planting density of the park increased, but the thermal comfort index PET, which is the degree of heat sensation felt by humans, was not directly proportional to temperature. The establishment of a pocket park reduced air temperature up to a radius of 56m, while the range of temperature reduction increased by about 12.5% when three additional pocket parks were established at 250m intervals. Unlike the air temperature, PET was only affected in the vicinity of the planted area, so there was no significant difference in the thermal comfort of the surrounding environment due to the construction of pocket parks. Changing the surface pavement from asphalt to lawn blocks and implementing rooftop or wall greening did not directly act as solar shading but positively affected air temperature reduction; PET showed no significant difference. Roadside planting showed a higher air temperature reduction effect as the planting interval was narrower, but PET was not directly proportional to tree density. In the case of shrub planting under trees, it did not significantly affect the air temperature reduction but positively affected the improvement of thermal comfort. This study can outline strategies for constructing neighborhood green spaces to solve the urban heat island phenomena and establish detailed strategies for efficient thermal environment improvements.

• International Commerce and Information Review
• /
• v.18 no.3
• /
• pp.181-201
• /
• 2016

In this study, transaction cost approach was applied to analysis on direct export determinants of SMEs by using key attributes of transactions, asset specificity, environmental uncertainty, frequency and marketing capability, with a parameter of opportunism. Typical Transaction Cost Analysis theory explains that when transaction cost with business channels(whether it is for buy or sell) increase, the firms integrate the channels. So it is a choice made by firms regarding direct versus indirect channels. The theory was extended to a model of choice of institutional form of direct or indirect export by a norm of opportunism in this empirical study. The survey result showed that lower level of asset specificity and marketing capability or higher level of environmental uncertainty were likely to expose indirect exporters to higher level of opportunism of direct exporter. And we also saw that indirect exporters were likely to choose direct export chanel when opportunism of exporters was higher. From the standpoint of theory, we can say that the basic propositions of the Transaction Cost Analysis, except the attribute of frequency, are supported. This study result could provide a profiling of target business areas and firms for government's policy on direct export promotion of SMEs.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.28 no.5
• /
• pp.366-372
• /
• 2017

In this paper, the analysis of baluns that are inevitably required to design a differential low noise amplifier, The balun converts a single signal input from the antenna into a differential signal, which serves as an input to the differential amplifier. In addition, it protects the circuit from ESD(Electrostatic Discharge) coming through the antenna and helps with input matching. However, in the case of a passive balun used in general, since the AC signal is transmitted through electromagnetic coupling formed between two metal lines, it not only has loss without gain but also has the greatest influence on the total noise figure of the receiving end. Therefore, the design of a balun in a low-noise amplifier is very important, and it is important to design a balun in consideration of line width, line spacing, winding, radius, and layout symmetry that are necessary. In this paper, the factors to be considered for improving the quality factor of balun are summarized, and the tendency of variation of resistance, inductance, and capacitance of the balun according to design element change is analyzed. Based on the analysis results, it is proved that the design of input balun allows the design of low noise, high gain differential amplifier with gain of 24 dB and noise figure of 2.51 dB.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.39 no.6
• /
• pp.21-35
• /
• 2011

This study is basic research which aims to compare and analyze changes in rural areas in modern times. The main purpose of this study is to comprehend the characteristics of changes in the Korean rural landscape and to suggest the implications for preservation and maintenance of the rural landscape. To help in understanding the rural landscape systematically, it should be divided into six types: housing landscape, cultivation landscape, green landscape, waterside landscape, streetscape and symbolic and religious landscape. According to this step, the contents and the procedures of changes were analyzed generally. Based on the literature review and field survey, the styles of changes were deduced to be formation, alternation, relocation, damage and restoration on landscape elements. Lastly, it was concluded that complex changes of landscape in rural areas from the government's development policy have been continued from macroscopic changes like overall structure and system of landscape to microscopic changes like shape, material, size and color of each landscape element. Rural villages which have not had the government's development policy applied to them may not be appropriate for this study. However, this study has significance in that it can suggest the direction for desirable rural planning. Future studies need to consider landscape change through not only the development policy but also economic, social and cultural factors.

• Journal of the Korea Society of Computer and Information
• /
• v.15 no.11
• /
• pp.1-9
• /
• 2010

As the process technology scales down, an interconnection has became a major performance constraint for multi-core processors. Recently, in order to mitigate the performance bottleneck of the interconnection for multi-core processors, a 3D integration technique has drawn quite attention. The 3D integrated multi-core processor has advantage for reducing global wire length, resulting in a performance improvement. However, it causes serious thermal problems due to increased power density. For this reason, to design efficient 3D multi-core processors, thermal-aware design techniques should be considered. In this paper, we analyze the temperature on the 3D multi-core processors in function unit level through various experiments. We also present temperature characteristics by varying application features, cooling characteristics, and frequency levels on 3D multi-core processors. According to our experimental results, following two rules should be obeyed for thermal-aware 3D processor design. First, to optimize the thermal profile of cores, the core with higher cooling efficiency should be clocked at a higher frequency. Second, to lower the temperature of cores, a workload with higher thermal impact should be assigned to the core with higher cooling efficiency.

• Nuclear Engineering and Technology
• /
• v.17 no.4
• /
• pp.290-301
• /
• 1985

600MW(e) CANDU Primary Heat Transport System (PHTS) is composed of the two “figure-of-eight” loops and is designed to operate with the 4% Reactor Outlet Header (ROH) quality at its rated power. This existence of the two compressible regions and the positive flow-qualitly-void feedbacks are the sources of the PHTS flow instability. To ensure the PHTS stability, ROH-ROH interconnect pipes are installed as passive systems. This paper describes the investigation of the PHTS flow instability at its design full power condition. Also studied are the interconnect effect and the inherent system damping effect on the system stability. The time domain stability analyses are accessed by using the ATHER/MOD-I code which is the improved version of the KAERI developed ATHER code. Under the most adverse system modelling, the “figure-of-eight” symmetric loop shows divergent flow oscillations. Under with the interconnect, the PHTS stability is remarkably enhanced so that the system becomes stable. However, even under the conservative pressurizer modelling, the PHTS shows the more convergent flow oscillations. With the interconnect and the pressurizer modelling, its stability is highly credited. Conclusively, the inherent system damping by pressurizer itself can credit the PHTS stability without the interconnect.

• The KIPS Transactions:PartD
• /
• v.15D no.1
• /
• pp.61-72
• /
• 2008

One of the most significant tasks of software development project is to know how much it will be the software development cost in the early stage of software development cycle. The software development environment and technology are changing very rapidly. For accuracy, we should apply those to the software cost estimation. And it is important that we select the suitable adjustment factor and the value of a suitable adjustment factor. For that, this paper have applied the method of AHP. And we have also analyzed the sensitivity of the adjustment factor which is influenced by decision metrics. In conclusion, the value of the application type adjustment factor is responded more sensitively to the data complexity and the control complexity than processing complexity. And the value of the language adjustment factor is responded more sensitively to the supplying manpower and the time of the coding than the time of the debugging. In the future, we will research the selection of an additional adjustment factor and a suitable value of the adjustment factor which are influenced by the environment and the technology of the domestic software development. And then, in the language adjustment factor, we will try to calculate the value about the individual programming language.

• Archives of design research
• /
• no.16
• /
• pp.161-170
• /
• 1996

In an attempt to teace trands in fashion journalism based on the examination of recent fashion magazines in korea, this study has dealt with the followings: the number of articles on fashion, image of fashion, characteristics of articles, change in "coordinate" and titles, and length of time of publication. The results of this study follow: 1. Among the general magazines for ladies whose titles have been changed, those dedicated to the "Ms class" have increased the pages on fashion and coverage of casual brand: those for housewives have shown no change in contents despite the change in titles, 2. The length of time of publication does not affect the change in the number of articles on fashion. General magazines for ladies have shown the greater "coordinate" in articles on fashion. 3. In terms of the contents of articles on fashion, those devoted to fashion and clothing are specialized and innovation-oriented, whereas general magaines stress the provision of more practical information. 4. The emergence of the X-generation and the newer generation has resulted in positioning of clothing crand, making them chief tarhet readers.ing them chief tarhet readers.