• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.3
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• pp.543-560
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• 2018

With the increased development in downtown underground space facilities that vertically cross under a railway at a shallow depth, the demand for non-open cut method is increasing. However, most construction sites still adopt the pipe roof method, where medium and large diameter steel pipes are pressed in to form a roof, enabling excavation of the inside space. Among the many factors that influence the loosening region and loads that occur while pressing in steel pipes, the size of the pipe has the largest impact, and this factor may correspond to the magnitude of load applied to the underground structure inside the steel pipe roof. The super equilibrium method (SEM) has been developed to minimize ground disturbance and loosening load, and uses small diameter pipes of approximately 114 mm instead of conventional medium and large diameter pipes. This small diameter steel pipe is called an SEM pile. After SEM piles are pressed in and the grouting reinforcement is constructed, a crossing structure is pressed in by using a hydraulic jack without ground subsidence or heaving. The SEM pile, which plays the role of timbering, is a fore-poling pile of approximately 5 m length that prevents ground collapse and supports surface load during excavation of toe part. The loosening region should be adequately calculated to estimate the spacing and construction length of the piles and stiffness of members. In this paper, we conducted a comparative analysis of calculations of loosening load that occurs during the press-in of SEM pile to obtain an optimal design of SEM. We analyzed the influence of factors in main theoretical and empirical formulas applied for calculating loosening regions, and carried out FEM analysis to see an appropriate loosening load to the SEM pile. In order to estimate the soil loosening caused by actual SEM-pile indentation and excavation, a steel pipe indentation reduction model test was conducted. Soil subsidence and soil loosening were investigated quantitatively according to soil/steel pipe (H/D).

• Journal of Animal Science and Technology
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• v.44 no.5
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• pp.541-548
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• 2002

This study, consisting of two experiments, was conducted to determine the effects of feeding heat treated protein and mineral complex (HPM) on milk production and composition, and ruminal fermentation of Holstein dairy cows. In in vitro experiment, HPM levels were 0, 0.2, 1 and 2%, and Timothy hay, which was substrate, was milled as 1 mm size, and the effects of HPM on pH, ammonia and VFA were analyzed after incubation times of 0, 6, 12, 24 and 48 h, respectively. The pH and ammonia production were not significantly different between treatments during the incubation. In addition, generally, total VFA and individual VFA were not affected by HPM on 0, 6 and 24 h. While, total VFA and individual VFA were increased in 0.2% and 1% of HPM supplemented treatments, but decreased in 2% of HPM treatment compared with control on 12 h. On 48 h, total VFA and individual VFA were increased in HPM treatments compared to control (P<0.05). However, A/P ratio was not affected by HPM supplementation. Gas production was higher in HPM treatment compared to control on 24 h (P<0.05) and 48 h (P<0.05). In lactating experiment, fourteen lactating Holstein cows were used for 4 months in a cross over experimental design. There were two treatments; no added HPM as a control and 0.2% of HPM added as a test treatment. Daily milk yield (P<0.001), 4% FCM (P<0.001), milk protein (P<0.05) and SNF (solid not fat; P<0.05) were increased in HPM treatment compared to control. While, milk fat, MUN (milk urea nitrogen) and SCC (somatic cell count) were not significantly different between treatments.

• Current Research on Agriculture and Life Sciences
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• v.17
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• pp.21-29
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• 1999

This study was carried out to determine the promising method for the production of mother bulbs using garlic bulbs at the experimental field of Ange high school, Eusung in Korea from 1996 to 1998. The bulbs and bulbils were taken from a local cultivar 'Eusung' garlic. The growth of bulbil and yield potential were compared with different harvesting times and cultivation methods of bulbil. The harvesting time of bulbils which were capable of producing the mother bulbs was ranged from 15 days to 30 days after the emergence of flower stalks. The best results based on the yield and number of bulbs were obtained from the bulbils sampled at the just before garlic harvesting, 30 days after flower-stalk emergence. The mulching with transparent polyethylene(PE) film in bulbil cultivation was more effective for the plant growth and bulb formation than that with black PE film. The PE mulching from 30 days after seeding of bulbils to 30 days (late-April) before bulb harvesting was the moot effective for the increase of bulb yield. In the cultivation of garlic bulbils, application of lime (150 kg/10a) and compost (3,000 kg/10a) without any chemical fertilizers produced more bulbs in comparison with the standard level of fertilizer (N - $P_2O_5$ - $K_2O$ - compost - lime = 24.8 - 8.0 - 19.2 - 3,000 - 150 kg/10a). It was determined that the involucre seeding and assemble seeding of bulbils was effective and labour-saving methods for the production of mother bulbs from garlic bulbils. Input of labour force for the involucre seeding was decreased up to 61% as compared with the conventional drill seeding of bulbils. Mean yield from the cultivation of bulbil-derived single cloves was remarkably increased up to 95% in comparison with that of the common cloves. The larger size of single clove produced more yields, and the optimum planting density of single clove was $20{\times}10cm$. The cloves differentiated directly from bulbil showed to have higher yield potential than that from common cloves.

• Journal of Intelligence and Information Systems
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• v.17 no.4
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• pp.157-173
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• 2011

As the Internet use explodes recently, the malicious attacks and hacking for a system connected to network occur frequently. This means the fatal damage can be caused by these intrusions in the government agency, public office, and company operating various systems. For such reasons, there are growing interests and demand about the intrusion detection systems (IDS)-the security systems for detecting, identifying and responding to unauthorized or abnormal activities appropriately. The intrusion detection models that have been applied in conventional IDS are generally designed by modeling the experts' implicit knowledge on the network intrusions or the hackers' abnormal behaviors. These kinds of intrusion detection models perform well under the normal situations. However, they show poor performance when they meet a new or unknown pattern of the network attacks. For this reason, several recent studies try to adopt various artificial intelligence techniques, which can proactively respond to the unknown threats. Especially, artificial neural networks (ANNs) have popularly been applied in the prior studies because of its superior prediction accuracy. However, ANNs have some intrinsic limitations such as the risk of overfitting, the requirement of the large sample size, and the lack of understanding the prediction process (i.e. black box theory). As a result, the most recent studies on IDS have started to adopt support vector machine (SVM), the classification technique that is more stable and powerful compared to ANNs. SVM is known as a relatively high predictive power and generalization capability. Under this background, this study proposes a novel intelligent intrusion detection model that uses SVM as the classification model in order to improve the predictive ability of IDS. Also, our model is designed to consider the asymmetric error cost by optimizing the classification threshold. Generally, there are two common forms of errors in intrusion detection. The first error type is the False-Positive Error (FPE). In the case of FPE, the wrong judgment on it may result in the unnecessary fixation. The second error type is the False-Negative Error (FNE) that mainly misjudges the malware of the program as normal. Compared to FPE, FNE is more fatal. Thus, when considering total cost of misclassification in IDS, it is more reasonable to assign heavier weights on FNE rather than FPE. Therefore, we designed our proposed intrusion detection model to optimize the classification threshold in order to minimize the total misclassification cost. In this case, conventional SVM cannot be applied because it is designed to generate discrete output (i.e. a class). To resolve this problem, we used the revised SVM technique proposed by Platt(2000), which is able to generate the probability estimate. To validate the practical applicability of our model, we applied it to the real-world dataset for network intrusion detection. The experimental dataset was collected from the IDS sensor of an official institution in Korea from January to June 2010. We collected 15,000 log data in total, and selected 1,000 samples from them by using random sampling method. In addition, the SVM model was compared with the logistic regression (LOGIT), decision trees (DT), and ANN to confirm the superiority of the proposed model. LOGIT and DT was experimented using PASW Statistics v18.0, and ANN was experimented using Neuroshell 4.0. For SVM, LIBSVM v2.90-a freeware for training SVM classifier-was used. Empirical results showed that our proposed model based on SVM outperformed all the other comparative models in detecting network intrusions from the accuracy perspective. They also showed that our model reduced the total misclassification cost compared to the ANN-based intrusion detection model. As a result, it is expected that the intrusion detection model proposed in this paper would not only enhance the performance of IDS, but also lead to better management of FNE.

• Korean Journal of Environment and Ecology
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• v.28 no.4
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• pp.457-471
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• 2014

This study aims to present an evaluation scheme to improve the problems in tree shapes and tree growth which were identified through shape and growth assessments of landscape trees currently planted in Haedoji Park, Songdo, Incheon Metropolitan City after plant structure status and propriety review for funtion of space and concept of planting. Suitability the planting concept was evaluated according to function of space. The result indicated that the shade planting areas accounted for 29.5% of the the shade spaces area. 58.7%, respectively planting areas of visual landscape. And 11.8%, respectively planting areas of buffer. Because the planting areas was lacked according to the park established spatial configuration of central facilities and the result of plant young trees. Plant structure status required consideration with plant structure, density, size, growth status for improve planting function. The tree assessment was performed on a total of 28 species and 600 trees of which 22 species and 209 trees were planted in the buffer zone, 8 species and 71 trees in the shade zone, 16 species and 266 trees in the visual landscape zone, and 4 species and 54 trees in the ecological landscape zone. The trees were divided into grades based on their assessment score and were statistically grouped by the functional zone in where they are planted and by tree species to verify their significance. The tree shape assessment was an average of 56.6 points and the tree growth assessment was an average of 76.0 points. Using the results of the tree assessments, the tree standards for each functional space were identified and a concept of optimum planting and cultivating was applied. When applying the shape assessment results by zone to the concept of planting, since trees for buffering require high functionality they received E's, the lowest grade; as trees for ecological landscaping require diverseness and naturalness, they received D's; since trees for shading require utilization, they received C's as trees with branching at the main stems were considered; and since trees for visual landscaping required aesthetical value, they received A's and B's. When applying the growth assessment results by zone to the concept of planting, based on planting foundations of favorable and poor, for buffering, visual landscaping, and ecological landscaping, trees from grades A to E could be planted, and for shading, trees from grades A to C could be planted. For a cultivation plan that could improve the growth of the trees, we proposed that the topography of the land be selected considering the tree's characteristics and that a method of pot seeding be used. Also, to improve the shape of the trees, we proposed that poles be used to improve the growth of vertically-straight stems, an appropriate planting density be applied for reasonable branch growth, manage tree shape to maintain good crowning, and better manage fertilization to maintain a reasonable crown density.

• KSBB Journal
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• v.22 no.5
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• pp.297-304
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• 2007

For large and rapid screening of high-yielding mutants of lovastatin produced by filamentous fungal cells of Aspergillus terreus, one of the most important stage is to test as large amounts of mutated strains as possible. For this purpose, we intended to develop a miniaturized cultivation method using $7m{\ell}$ culture tube instead of traditional $250m{\ell}$ flask (working volume $50m{\ell}$). For obtaining large amounts of conidiospores to be used as inoculums for miniaturized cultures, 4 components i.e., glucose, sucrose, yeast extract and $KH_2PO_4$ were intensively investigated, which had been observed to show positive effect on enhancement of spore production through Plackett-Burman design experimet. When optimum concentrations of these components that were determined through application of response surface method (RSM) based on central composite design (CCD) were used, maximum spore numbers amounting to $1.9\times10^{10}$ spores/plate were obtained, resulting in approximately 190 fold increase as compared to the commonly used PDA sporulation medium. Using the miniaturized cultures, intensive strain development programs were carried out for screening of lovastatin high-yielding as well as highly reproducible mutants. It was observed that, for maximum production of lovastatin, the producers should be activated through 'PaB' adaptation process during the early solid culture stage. In addition, they should be proliferated in condensed filamentous forms in miniaturized growth cultures, so that optimum amounts of highly active cells could be transferred to the production culture-tube as reproducible inoculums. Under these highly controlled fermentation conditions, compact-pelleted morphology of optimum size (less than 1 mm in diameter) was successfully induced in the miniaturized production cultures, which proved essential for maximal utilization of the producers' physiology leading to significantly enhanced production of lovastatin. As a result of continuous screening in the miniaturized cultures, lovastatin production levels of the 81% of the daughter cells derived from the high-yielding producers turned out to be in the range of 80%$\sim$120% of the lovastatin production level of the parallel flask cultures. These results demonstrate that the miniaturized cultivation method developed in this study is efficient high throughput system for large and rapid screening of highly stable and productive strains.

• The korean journal of orthodontics
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• v.35 no.6 s.113
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• pp.475-484
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• 2005

This study was performed to investigate the reproducibility of the horizontal and midsagittal planes, and to suggest a stable coordinate system for three-dimensional (3D) cephalometric analysis. Eighteen CT scans were taken and the coordinate system was established using 7 reference points marked by a volume model, with no more than 4 points on the same plane. The 3D landmarks were selected on V works (Cybermed Inc., Seoul, Korea), then exported to V surgery (Cybermed Inc., Seoul, Korea) to calculate the coordinate values. All the landmarks were taken twice with a lapse of 2 weeks. The horizontal and midsagittal planes were constructed and its reproducibility was evaluated. There was no significant difference in the reproducibility of the horizontal reference planes, But, FH planes were more reproducible than other horizontal planes. FH planes showed no difference between the planes constructed with 3 out of 4 points. The angle of intersection made by 2 FH planes, composed of both Po and one Or showed less than $1^{\circ}$ difference. This was identical when 2 FH planes were composed of both Or and one Po. But, the latter cases showed a significantly smaller error. The reproducibility of the midsagittal plane was reliable with an error range of 0.61 to $1.93^{\circ}$ except for 5 establishments (FMS-Nc, Na-Rh, Na-ANS, Rh-ANS, and FR-PNS). The 3D coordinate system may be constructed with 3 planes; the horizontal plane constructed by both Po and right Or; the midsagittal plane perpendicular to the horizontal plane, including the midpoint of the Foramen Spinosum and Nc; and the coronal plane perpendicular to the horizontal and midsagittal planes, including point clinoidale, or sella, or PNS.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.2
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• pp.120-127
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• 2015

Purpose: The aim was to investigate the effect of implant thread designs on the stress dissipation of the implant. Materials and methods: The threads evaluated in this study included the V-shaped, buttress, reverse buttress, and square-shaped threads, which were of the same size (depth). Building four different implant/bone complexes each consisting of an implant with one of the 4 different threads on its cylindrical body ($4.1mm{\times}10mm$), a force of 100 N was applied onto the top of implant abutment at $30^{\circ}$ with the implant axis. In order to simulate different osseointegration stages at the implant/bone interfaces, a nonlinear contact condition was used to simulate immature osseointegration and a bonding condition for mature osseointegration states. Results: Stress distribution pattern around the implant differed depending on the osseointegration states. Stress levels as well as the differences in the stress between the analysis models (with different threads) were higher in the case of the immature osseointegration state. Both the stress levels and the differences between analysis models became lower at the completely osseointegrated state. Stress dissipation characteristics of the V-shape thread was in the middle of the four threads in both the immature and mature states of osseointegration. These results indicated that implant thread design may have biomechanical impact on the implant bed bone until the osseointegration process has been finished. Conclusion: The stress dissipation characteristics of V-shape thread was in the middle of the four threads in both the immature and mature states of osseointegration.

• Tuberculosis and Respiratory Diseases
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• v.51 no.2
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• pp.147-154
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• 2001

Background : Bronchoscopy has been widely used for a histologic diagnosis through a transbronchial lung biopsy or for staging of patients with peripheral lung cancer. However a transthoracic needle aspiration (TTNA) has been used more widely for a histologic diagnosis in patient with a small size nodule or a nodule located in the outer portion of the lung because of the low diagnostic yield of bronchoscopy in these cases. The role of bronchoscopy for staging is not well established in patients with peripheral lung cancer diagnosed by a TTNA or patients who are undergoing surgery without a histologic diagnosis. Method: To evaluate the role of bronchoscopy for the staging in patients with peripheral lung cancer, who were diagnosed by TTNA, the medical records of 86 patients with peripheral lung cancer who underwent bronchoscopyat Kyungpook National University Hospital between January 1995 and May 1997 were reviewed. Results : While 53 cases had normal bronchoscopic findings, 33 cases had abnormal bronchoscopic findings comprising 9 cases of tumor, 10 cases of infiltration and 14 cases of compression of which there were 25 cases of T1 and 8 T2 endoscopically. The bronchoscopic staging did not influence the changes of the clinical stage of lung cancer. The frequencies of bronchial involvement tended to increase as the sizes of the nodule increased. Among the 42 patients who underwent surgery, 9 patients staged higher after operation because of lymph node involvement in 8 patients and the involvement of the pulmonary artery in 1 patient. No case staged above after operation due to a bronchial invasion. Conclusion : These findings suggests that bronchoscopy is not useful for staging in patients with peripheral lung cancer diagnosed by a TTNA.

• Information Systems Review
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• v.18 no.1
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• pp.57-78
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• 2016

Hacking has raised many critical issues in the modern world, particularly because the size and cost of the damages caused by this disruptive activity have steadily increased. Accordingly, many significant studies have been conducted by behavioral scientists to understand hackers and their practices. Nonetheless, only qualitative methods, such as interviews, meta-studies, and media studies, have been employed in such studies because of hacker sampling limitations. Existing studies have determined that intrinsic motivation was the dominant factor influencing hackers, and that their techniques were mainly acquired from online hacking communities. However, such results have yet to be causally proven. This study attempted to identify the causal factors influencing the motivational and environmental factors encouraging hackers to learn hacking skills. To this end, hacker community members using the theory of planned behavior were observed to identify the causal factors of their learning of hacking skills. We selected a group of students who were developing their hacking skills. The survey was conducted over a two-week period in May 2015 with a total of 227 students as respondents. After list-wise deletion, 215 of the responses were deemed usable (94.7 percent). In summary, the hackers were aware that hacking skills are considered socially unethical, and their attitudes toward the learning of hacking skills were affected by both intrinsic and extrinsic motivations. In addition, the characteristics of the online hacking community affected their perceived behavioral control. This study introduced new concepts in the process of conducting a causal relationship analysis on a hacker sample. Moreover, this research expanded the discussion on the causal direction of subjective norms in unethical research, and empirically confirmed that both intrinsic and extrinsic motivations affect the learning of hacking skills. This study also made a practical contribution by raising the educational and policy response issues for ethical hackers and demonstrating the necessity to intensify the punishment for hacking.