• Journal of Digital Convergence
• /
• v.20 no.2
• /
• pp.217-223
• /
• 2022

Subspace clustering for online data streams requires a large amount of memory resources as all subsets of data dimensions must be examined. In order to track the continuous change of clusters for a data stream in a finite memory space, in this paper, we propose a grid-based subspace clustering algorithm that effectively uses memory resources. Given an n-dimensional data stream, the distribution information of data items in data space is monitored by a grid-cell list. When the frequency of data items in the grid-cell list of the first level is high and it becomes a unit grid-cell, the grid-cell list of the next level is created as a child node in order to find clusters of all possible subspaces from the grid-cell. In this way, a maximum n-level grid-cell subspace tree is constructed, and a k-dimensional subspace cluster can be found at the k^th level of the subspace grid-cell tree. Through experiments, it was confirmed that the proposed method uses computing resources more efficiently by expanding only the dense space while maintaining the same accuracy as the existing method.

• Journal of the Korea Society for Simulation
• /
• v.18 no.4
• /
• pp.207-217
• /
• 2009

We propose a two-stage Distributed Denial of Service (DDoS) defense system, which can protect a given subnet by serving existing flows and new flows with a different priority based on IP history information. Denial of Service (DoS) usually occurs when the resource of a network node or link is limited and the demand of the users for that resource exceeds the capacity. The objective of the proposed defense system is to provide continued service to existing flows even in the presence of DDoS attacks. The proposed scheme can protect existing connections effectively with a smaller memory size by reducing the monitored IP address set through sampling and per-prefix history management. We evaluate the performance of the proposed scheme through simulation.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.2A
• /
• pp.114-126
• /
• 2011

Video streaming over wireless multi-hop networks(WMNs) contains the following challenges from channel fading and variable bandwidth of wireless channel, and it cause degradation of video streaming performance. To overcome the challenges, currently, WMNs can use Forward Error Correction (FEC) mechanism. In WMNs, traditional FEC schemes, E2E-FEC and HbH-FEC, for video streaming are applied, but it has long transmission delay, high computational complexity and inefficient usage of resource. Also, to distinguish network status in streaming path, it has limitation. In this paper, we propose monitoring-based coordination of network-adaptive hop-to-end(H2E) FEC scheme. To enable proposed scheme, we apply a centralized coordinator. The coordinator has observing overall monitoring information and coordinating H2E-FEC mechanism. Main points of H2E-FEC is distinguishing operation range as well as selecting FEC starting node and redundancy from monitored results in coordination. To verify the proposed scheme, we perform extensive experiment over the OMF(Orbit Measurement Framework) and IEEE 802.1la-based multi-hop WMN testbed, and we carry out performance improvement, 17%, from performance comparison by existing FEC scheme.

• Journal of Veterinary Clinics
• /
• v.17 no.2
• /
• pp.443-449
• /
• 2000

A three-year-old male jindo with generalized skin lesions (including seborrhea, hyperk- eratosis, alopecia, papules, and ecchymoses), pruritus lymph node enlargement, and fever was brought to Veterinary Teaching Hospital, College of Veterinary Medicine, Chungbuk National Uni- versity. There were no laboratory findings for parasites and fungi in the hair and skin But, the com- plete blood counts (CBC) showed leukocytosis and severe cosinophilia, It was suspected to be an inflammatory and allergic dermatitis. Thus, prednisoIone (0.5 mg/kg PO, BID for 1 week) and ampi- cillin (10 mg/kg PO, BID for 1 week given. One week later, pruritus and ecchymoses were reduced. These treatments were repeated for 7 day again. Three months later, the dog was presented again due to the relapse and exacerbation of the clinical signs. The signs were as follows; severe pru- ritus, vesicobullous skin lesions, anorexia, emaciation, lameness, and welling of carpal joints that showed inflammatory skin lesion and draining of synovia-like fluid. The values of WBC counts were returned to normal ranges. In contrast, eosinophilia was still observed. Coombs test for patient RBC and serum were negative. Hypoalbuminemia (2.5g/dl) was shown by serum chemistry. The uri- nalysis revealed and presence of leukocytes. Luxation finding of right radial carpal joint by polyarthritis was shown in radiography of affected joints.Lupus eryhematosus(LE) cells also appeared in peripheral blood and synovial fluid of affected joints. Definitely, antinuclear antibody (ANA) of patient serum using feline peripheral blood mononuclear cells was detected by all immu- nofluorescence. Based on these findings such as sedum ANA-Positive. major signs (skin disease, non- erosive polyarthritis with soft tissue swelling. and proteinuria), minor signs (fever), and LE cell-pos- itive, a diagnosis of systemic lupus crythematosus (SLE) was mad\ulcorner in this dog. The dog with SLE was administered with Pre(2.0 mg/kg PO, BID for first 4 week and then QOD) to inhibit the production of autoantibodies and with ampicillin (10 mg/kg PO, BID for first 4 weeks and then QOD) to prevent the secondary infection. The condition of this dog was monitored every 2 weeks by physical examinations, radiography, CBC, serum chemistry and urinalyais. At 8th week of treat- ment, the state of SLE evaluated by physical examinations and laboratory findings was markedly improved except for proteinura.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.18 no.5
• /
• pp.34-48
• /
• 2019

The purpose of this study was two-fold; first, to develop safety performance functions (SPF) using transportation-related big data for all types of roads in Korea were developed, Second, to provide basic information to develop measures for relatively dangerous roads by evaluating the safety grade for various roads based on it. The coordinates of traffic accident data are used to match roads across the country based on the national standard node and link system. As independent variables, this study effort uses link length, the number of traffic volume data from ViewT established by the Korea Transport Research Institute, and the number of dangerous driving behaviors based on the digital tachograph system installed on commercial vehicles. Based on the methodology and result of analysis used in this study, it is expected that the transportation safety improvement projects can be properly selected, and the effects can be clearly monitored and quantified.

• Journal of Digestive Cancer Research
• /
• v.1 no.1
• /
• pp.48-51
• /
• 2013

We report an unusual case of postoperative early gastric cancer with liver metastasis mimicking pancreaticobiliary carcinoma. A 73-year-old man with early gastric cancer was transferred for endoscopic treatment. The patient underwent endoscopic submucosal dissection for the treatment of the early gastric cancer. The pathological diagnosis was adenocarcinoma with extension to the deep submucosa and some lymphatic invasion. Therefore, subsequent a subtotal gastrectomy was performed. The histological results demonstrated residual adenocarcinoma confined to the mucosa. The resection margin and lymph node metastasis were negative. Thus, he was closely monitored for recurrence every 6 months. After 2 years, he was suddenly suspected of developing liver metastasis and local recurrence. He received a liver biopsy, and the pathological result was poorly differentiated adenocarcinoma. Immunohistochemical staining suggested pancreaticobiliary carcinoma rather than metastatic adenocarcinoma from the stomach or colon, but primary focus was not found. We were sure that the recurrent stomach cancer metastasized to the liver because stomach cancer can show heterogeneous cytokeratin (CK) expression pattern with various histological features. Therefore, no single CK expression pattern has diagnostic value for distinguishing gastric carcinoma. The patient underwent chemotherapy for metastatic stomach cancer.

• Korean Journal of Environmental Agriculture
• /
• v.37 no.4
• /
• pp.251-259
• /
• 2018

BACKGROUND: Various culture media have been used for hydroponic cultures of horticultural plants under the smart greenhouses with natural and artificial light types. Management of the culture medium for the control of medium amounts and/or necessary components absorbed by plants during the cultivation period is performed with ICT (Information and Communication Technology) and/or IoT (Internet of Things) in a smart farm system. This study was conducted to develop the cloud-based data analysis system for effective management of culture medium applying to hydroponic culture and plant growth in smart greenhouses. METHODS AND RESULTS: Conventional inorganic Yamazaki and organic media derived from agricultural byproducts such as a immature fruit, leaf, or stem were used for hydroponic culture media. Component changes of the solutions according to the growth stage were monitored and plant growth was observed. Red and green lettuce seedlings (Lactuca sativa L.) which developed 2~3 true leaves were considered as plant materials. The seedlings were hydroponically grown in the smart greenhouse with fluorescent and light-emitting diodes (LEDs) lights of $150{\mu}mol/m^2/s$ light intensity for 35 days. Growth data of the seedlings were classified and stored to develop the relational database in the virtual machine which was generated from an open stack cloud system on the base of growth parameter. Relation of the plant growth and nutrient absorption pattern of 9 inorganic components inside the media during the cultivation period was investigated. The stored data associated with component changes and growth parameters were visualized on the web through the web framework and Node JS. CONCLUSION: Time-series changes of inorganic components in the culture media were observed. The increases of the unfolded leaves or fresh weight of the seedlings were mainly dependent on the macroelements such as a $NO_3-N$, and affected by the different inorganic and organic media. Though the data analysis system was developed, actual measurement data were offered by using the user smart device, and analysis and comparison of the data were visualized graphically in time series based on the cloud database. Agricultural management in data visualization and/or plant growth can be implemented by the data analysis system under whole agricultural sites regardless of various culture environmental changes.