• Korean Journal of Veterinary Research
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• v.16 no.1
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• pp.11-25
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• 1976

Studies on pathogenicities and developmental stages of Nosema apis (Zander, 1909) were carried out through artificial infection to Nosema free honey bees with various levels of spores isolated from local honey bee colony. The results obtained were summarized as follows: 1. The clinical symptoms were observed as dysentery, enteritis of mid-gut (enlargement and decoloration), crawling posture and shortening of the longevity of worker bees in the rearing honey bee colony inoculated with the spores. 2. Number of spores harvested from laboratory rearing honey bees were progresively increased to 4 weeks after inoculation. The regression equations and coefficients of correlations to various spore levels were as follows in each treatment colony. Colony 1. ($$1,000{\times}10^4spores/ml$$) $$y_{c1}=471{\times}10^{4}x+454{\times}10^4(r=0.65^*$$) Colony 2. ($$500{\times}10^4spores/ml$$) $$y_{c2}=340{\times}10^{4}x+207.8{\times}10^4(r=0.99^{**}$$) Colony 3. ($$100{\times}10^4spores/ml$$) $$y_{c3}=150{\times}10^{4}x+84.2{\times}10^4(r=0.99^{**}$$) Colony 4. ($$10{\times}10^4spores/ml$$) $$y_{c4}=13.8{\times}10^{4}x+13{\times}10^4(r=0.98^{**}$$) 3. Average longevity of worker bees artificially infected with Nosema apis was shortened as 21.7~43.8% compare to the control. (p<.05, p<.01) 4. The spores which were isolated from honey bee colony infected with Nosema disease were ovoid or spherical form, and measured, as a rule, from $4.7{\mu}m$ to $6.1{\mu}m$ (mean $5.3{\mu}m$) in length and from $2.4{\mu}m$ to $3.2{\mu}m$ (mean $2.9{\mu}m$) in width. 5. In the mid-gut of honey bees, the spore was progresively germinated and became trophozoite stage. The trophozoites were grown to meronts and their binary fission were begun. The divided two sporoblasts were developed to the spores which had elastic membrane. The new spores were shed in excreta of honey bees 10~15 day after inoculation at $25{\pm}2$ centigrade. 6. The ultrastructure of spore membrane consisted of three layers, such as, outer, middle and inner layer. The sporoplasm consisting lamellar structure occupied only anterior part of the spore and was often extended to posterior direction where definite vacuoles and a polar filament was able to detect.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.1
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• pp.141-148
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• 2012

The objective of this study is to remove arsenate from artificially contaminated wastewater using CaAl-ettringite and CaAl-monosulfate which were synthesized in laboratory. The study was carried on the basis of solidification/stabilization of waste using cement. Monosulfate and ettringite are constituents of cement paste. The CaAl-ettringite has a chemical formula of $Ca_6Al_2O_6(SO_4)_3{\cdot}32H_2O$ and has a needle like morphology. Whereas CaAl-monosulfate $Ca_4Al_2O_6(SO_4){\cdot}12H_2O$ has layered double hydroxide structure (LDH) in which the mainlayer consists of Ca and Al and S as interlayer. Ettringite and monosulfate were synthesized by reaction of tricalcium aluminate and gypsum and hydrating this mixture at elevated temperature. The synthesized mineral were characterized by PXRD and FESEM to ensure purity. It was found that concentrations of As(V) in contaminated water were reduced from initial concentration of 1.335 mmol/L to 0.054 mmol/L and 0.300 mmol/L by CaAl-monosulfate and CaAl-ettringite respectively. The post experimental results of PXRD and FESEM analysis indicate that arsenate removal was by ion exchange.

• Journal of the Korean Association of Geographic Information Studies
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• v.7 no.3
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• pp.22-34
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• 2004

An artificial disturbance like fragmentation in watershed forest has impacted a sustainability of watershed ecosystem, therefore this research quantified the landscape structure in the Geumho river watershed using landscape indices and GIS. Landscape indices were calculated from the forest distributed maps for 24 subwatersheds. Three common factors, which explained about 85% of the variation in the original data, were extracted by a factor analysis. The fragmentation gradient in forest landscape, which was calculated from the factor scores, was correlated with proportion of urban land (r=0.827, p<0.01, $R^2$=0.685), elevation (r=-0.637, p<0.01) and slope gradient (r=-0.593, p<0.01). The result of the study presented that the methodology and the values of landscape indices to assess the structural patterns of forest landscape for the Geumho river watershed management. Future research will be directed towards the detection of impacts of landscape patterns and their changes on the integrity of watershed environments.

• Korean Journal of Environment and Ecology
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• v.33 no.6
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• pp.686-694
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• 2019

This study was carried out to identify the long-term changes to beech forest due to climate change in Ulleung-do. To study the traits of the stand structure of beech forest with micro-topography, we investigated the distribution of the basal area, important values, and indicated species in a small ridge between Albong basin and Seongin-bong peak, and 1-ha stands (20 m × 20 m, 25 sites) dominated beech species including on the upper slope and valley parts. The result showed that the indicator species characterizing the vegetation communities were Tsuga sieboldii, Rhododendron brachycarpum, and Mitchella undulata in the small ridge and Celtis jessoensis, Dryopteris crassirhizoma, and Ulmus laciniata in the valley part. Moreover, the individuals with the total DBH < 10 cm were more predominant in the small ridge and upper slope than in the valley part, the individuals with DBH = 10-25 cm were predominant in the small slope, and individuals with DBH = 25-45 cm and DBH > 45 cm were predominant in the upper slope. The reason for the predominant distribution of beech stand with DBH<10 cm in all terrains is suggested to be germination by nutritional propagation rather than secondary succession caused by artificial disturbances and seed propagation.

• Journal of Korean Society of Forest Science
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• v.102 no.3
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• pp.446-454
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• 2013

The present study investigated the biological agents and environmental conditions of the habitats of the Kirengeshoma koreana, a class 2 endangered species class according to the South Korean Ministry of Environment (MOE), elucidated the structural characteristics of the forest stands in the habitats with the importance value and the diversity index, conducted comparative analysis of the factors, and explored their relationship with environmental factors. According to the results of direction analysis of natural habitats of the Kirengeshoma koreana, the direction was distributed to the north or the northeast, and the slope amounted to $15-40^{\circ}$, thus demonstrating that the slope has little effect. In addition, the results showed that the distribution of Kirengeshoma koreana populations dramatically increased starting in areas at least 600 m above the sea level and that the relative light intensity was 3.79% on an average. Most populations were native to gorges and crevices between rocks so that they mainly tended to inhabit areas that could see soil loss in times of precipitation. In addition, a considerable number of the populations were close to hiking trails as well, thus leading to concerns about their artificial destruction. The soil of layer a in the main growth space of the Kirengeshoma koreana was analyzed and turned out to be strongly acidic, measuring pH 4.45-4.89 (average: 4.68). All investigation sections were typical natural broad-leaved tree areas, and, judging from the fact that the Kirengeshoma koreana was most likely to appear in colonies of the Mongolian oak tree (Quercus mongolica Fisch. ex Ledeb.), the Mongolian oak tree seems to be the species of tree that has the greatest effect on the inhabitation of the Kirengeshoma koreana.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.4
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• pp.49-59
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• 2017

Smart sensing plays a key role in a variety of IoT applications, and its importance is growing more and more together with the development of artificial intelligence. Therefore the importance of smart sensors cannot be overemphasized. However, most studies related to smart sensors have been focusing on specific application purposes, for example, security, energy saving, monitoring, and there are not much effort on researches on how to efficiently configure various types of smart sensors to be needed in the future. In this paper, a component-based framework with hierarchical structure for efficient construction of smart sensor is proposed and its application to smart home is designed and implemented. The proposed method shows that various types of smart sensors to be appeared in the near future can be configured through the design and development of necessary components within the proposed software framework. In addition, since it has a layered architecture, the configuration of the smart sensor can be expanded by inserting the internal or external layers. In particular, it is possible to independently design the internal and external modules when designing an IoT application service through connection with the external device layer. A small-scale smart home system is designed and implemented using the proposed method, and a home cloud operating as an external layer, is further designed to accommodate and manage multiple smart homes. By developing and thus adding the components of each layer, it will be possible to efficiently extend the range of applications such as smart cars, smart buildings, smart factories an so on.

• Journal of Navigation and Port Research
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• v.44 no.4
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• pp.305-311
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• 2020

Rising sea levels along the coast from global warming causes the increase of wave energy along the coast. This rise in sea levels results in relatively deep water levels, which would incur the loss of sand that had not occurred in the past from erosion in coastal areas. Generally, it has been challenging to protect against coastal erosion, and the slope, cross-sectional shape, and materials are selected for the site conditions depending on the change in external forces. However, the application of counter measures based on insufficient understanding of the phenomenon is causing various damage, indicating the need for technological development and converging technologies to improve credibility. In this study, we developed eco-friendly permeable biopolymer concrete blocks to control the coastal erosion by using the Bio-Coast, an effective porous structure that mitigates the destructive erosion caused by the rising sea levels. The hexagonal design of Bio-Coast was derived from the honeycomb, columnar joints, and clover, which are durable and stable structures in nature, and the design was changed to apply bumps on the Bio-Coast filling in the form of a clover to reduce wave overtopping and run-up. Applying the field condition of beaches on the east coast of Korea, the block weight and size were decided and the prototype blocks were manufactured and are ready for field placement. In particular, it is intended to protect coastal areas from destructive erosion by natural and artificial external forces, and to extend the design to river,s lakes, and natural walking trails, to improve the efficiency of quality control and process control through the use of blocks.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.399-399
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• 2008

Synthesis and characterization of ZnO structure such as nanowires, nanorods, nanotube, nanowall, etc. have been studied to multifunctional application such as optical, nanoscale electronic and chemical devices because it has a room-temperature wide band gap of 3.37eV, large exiton binding energy(60meV) and various properties. Various synthesis methods including chemical vapor deposition (CVD), physical vapor deposition, electrochemical deposition, micro-emulsion, and hydrothermal approach have been reported to fabricate various kinds of ZnO nanostructures. But some of these synthesis methods are expensive and difficult of mass production. Wet chemical method has several advantage such as simple process, mass production, low temperature process, and low cost. In the present work, ZnO nanorods are deposited on ITO/glass substrate by simple wet chemical method. The process is perfomed by two steps. One-step is deposition of ZnO seeds and two-step is growth of ZnO nanorods on substrates. In order to form ZnO seeds on substrates, mixture solution of Zn acetate and Methanol was prepared.(one-step) Seed layers were deposited for control of morpholgy of ZnO seed layers by spin coating process because ZnO seeds is deposited uniformly by centrifugal force of spin coating. The seed-deposited samples were pre-annealed for 30min at $180^{\circ}C$ to enhance adhesion and crystallinnity of ZnO seed layer on substrate. Vertically well-aligned ZnO nanorods were grown by the "dipping-and-holding" process of the substrates into the mixture solution consisting of the mixture solution of DI water, Zinc nitrate and hexamethylenetetramine for 4 hours at $90^{\circ}C$.(two-step) It was found that density and morphology of ZnO nanorods were controlled by manipulation of ZnO seeds through rpm of spin coating. The morphology, crystallinity, optical properties of the grown ZnO nanostructures were carried out by field-emission scanning electron microscopy, high-resolution electron microscopy, photoluminescence, respectively. We are convinced that this method is complementing problems of main techniques of existing reports.

• Journal of The Korean Association For Science Education
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• v.38 no.2
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• pp.219-234
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• 2018

In this study, we explored the possibility of automating the process of analyzing elements of scientific argument in the context of a Korean classroom. To gather training data, we collected 990 sentences from science education journals that illustrate the results of coding elements of argumentation according to Toulmin's argumentation structure framework. We extracted 483 sentences as a test data set from the transcription of students' discourse in scientific argumentation activities. The words and morphemes of each argument were analyzed using the Python 'KoNLPy' package and the 'Kkma' module for Korean Natural Language Processing. After constructing the 'argument-morpheme:class' matrix for 1,473 sentences, five machine learning techniques were applied to generate predictive models relating each sentences to the element of argument with which it corresponded. The accuracy of the predictive models was investigated by comparing them with the results of pre-coding by researchers and confirming the degree of agreement. The predictive model generated by the k-nearest neighbor algorithm (KNN) demonstrated the highest degree of agreement [54.04% (${\kappa}=0.22$)] when machine learning was performed with the consideration of morpheme of each sentence. The predictive model generated by the KNN exhibited higher agreement [55.07% (${\kappa}=0.24$)] when the coding results of the previous sentence were added to the prediction process. In addition, the results indicated importance of considering context of discourse by reflecting the codes of previous sentences to the analysis. The results have significance in that, it showed the possibility of automating the analysis of students' argumentation activities in Korean language by applying machine learning.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.19 no.1
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• pp.123-136
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• 1989

The purpose of this study was to decide the diagnostic value of transmaxillary and transcranial projection in the evaluation of mandibular condyles. Five dry skulls with intact anatomic structure were selected for this study and the artificial osteophytes were attached to 9 different are as of the mandibular condyle. Ninety transcranial and forty-five transmaxillary radiographs were taken and then the radiographs were evaluated three times. The results were as follows; In transcranial radiographs, superocentral osteophyte was easily observed in closing state than in opening state (p<0.05). But there were no significant differences in other locations (p>0.05). The osteophytes on the medial and central portion easily observed at the transmaxillary projection than transcranial projection (p<0.05), but there was no significant difference on the lateral portion (p>0.05). The osteophytes on the superior (p<0.01) and posterior (p<0.01.) portion were easily observed at the transmaxillary projection than transcranial projection, but there was no significant difference on the anterior portion (p >0.05). The more laterally located osteophytes (p<0.01) at the transcranial projections were easily observed. The more posteriorly located osteophytes (p<0.05) at the transmaxillary projections were easily observed.