• Journal of Internet of Things and Convergence
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• v.10 no.2
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• pp.77-84
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• 2024

Over the past few years, IoT edges have begun to emerge based on new low-latency communication protocols such as 5G. However, IoT edges, despite their enormous advantages, pose new complementary threats, requiring new security solutions to address them. In this paper, we propose a cloud environment-based IoT edge architecture model that complements IoT systems. The proposed model acts on machine learning to prevent security threats in advance with network traffic data extracted from IoT edge devices. In addition, the proposed model ensures load and security in the access network (edge) by allocating some of the security data at the local node. The proposed model further reduces the load on the access network (edge) and secures the vulnerable part by allocating some functions of data processing and management to the local node among IoT edge environments. The proposed model virtualizes various IoT functions as a name service, and deploys hardware functions and sufficient computational resources to local nodes as needed.

• Radiation Oncology Journal
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• v.17 no.2
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• pp.172-178
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• 1999

Purpose : To measure the basic structural characteristics of radiation oncology facilities in Korea during 1997 and to compare personnel, equipments and patient loads between Korea and developed countries. Methods and Materials : Mail serveys we conducted in 1998 and data on treatment machines, personnel and peformed new patients were collected. Responses were obtained from the 100 percent of facilities. The consensus data of the whole country were summarized using Microsoft Excel program. Results: In Korea during 1997, 42 facilities delivered megavoltage radiation theraphy with 71 treatment machines, 100 radiation oncologists, 26 medical physicist, 205 technologists and 19,773 new patients. Eighty nine percent of facilities in Korea had linear accelators at least 6 MeV maximum photon energy. Ninety five percent of facilities had simulators while five percent of facilities had no simulator, Ninety one percent of facilities had computer planning systems and eighty three percent of facilities reported that they had a written quality assurance program. Thirty six percent of facilities had only one radiation oncologist and thirty eight percent of facilities had no medical physicists. The median of the distribution of annual patients load of a facility, patients load per a machine, patients load per a radiation oncologist, patients load per a therapist and therapists per a machine in Korea were 348 patients per a year, 263 patients per a machine, 171 patients per a radiation oncologist, 81 patients per a therapist, and 3 therapists per a machine respectively. Conclusions : The whole scale of the radiation oncology departments in Korea was smaller than Japan and USA in population ratio regard. In case of hardware level like linear accelerators, simulators and computer planning systems, there was no big differences between Korea and USA. The patients loads of radiation oncologists and therapists had no significant differences as compared with USA. However, it was desirable to consider the part time system in USA because there were a lot of hospitals which did not employ medical physicists.

• Proceedings of the Korean Society of Laser Processing Conference
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• 1998.11a
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• pp.0-0
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• 1998

-Part I- As market needs become more various, the production of smaller quantities of a wider variety of products becomes increasingly important. In addition, in order to meet demands for more efficient production, long-term unmanned factory operation is prevailing at a remarkable pace. Within this context, laser machines are gaining increasing popularity for use in applications such as cutting and welding metallic and ceramic materials. FANUC supplies four models of $CO_2$ laser oscillators with laser power ranging from 1.5㎾ to 6㎾ on an OEM basis to machine tool builders. However, FANUC has been requested to produce laser oscillators that allow more compact and lower-cost laser machines to be built. To meet such demands, FANUC has developed six models of Slab type YAG laser oscillators with output power ranging from 150W to 2㎾. These oscillators are designed mainly fur cutting and welding sheet metals. The oscillator has an exceptionally superior laser beam quality compared to conventional YAG laser oscillators, thus providing significantly improved machining capability. In addition, the laser beam of the oscillator can be efficiently transmitted through quartz optical fibers, enabling laser machines to be simplified and made more compact. This paper introduces the features of FANUC’s developed Slab type YAG laser oscillators and their applications. - Part II - All-solid-state lasers employing laser diodes (LD) as a source of pumping solid-state laser feature high efficiency, compactness, and high reliability. Thus, they are expected to provide a new generation of processing tools in various fields, especially in automobile and aircraft industries where great hopes are being placed on laser welding technology for steel plates and aluminum materials for which a significant growth in demand is expected. Also, in power plants, it is hoped that reliability and safety will be improved by using the laser welding technology. As in the above, the advent of high-power all-solid-state lasers may not only bring a great technological innovation to existing industry, but also create new industry. This is the background for this project, which has set its sights on the development of high-power, all-solid-state lasers with an average output of over 10㎾, an oscillation efficiency of over 20%, and a laser head volume of below 0.05㎥. FANUC Ltd. is responsible for the research and development of slab type lasers, and TOSHIBA Corp. far rod type lasers. By pumping slab type Nd: YAG crystal and by using quasi-continuous wave (QCW) type LD stacks, FANUC has already obtained an average output power of 1.7㎾, an optical conversion efficiency of 42%, and an electro-optical conversion efficiency of 16%. These conversion efficiencies are the best results the world has ever seen in the field of high-power all-solid-state lasers. TOSHIBA Corp. has also obtained an output power of 1.2㎾, an optical conversion efficiency of 30％, and an electro-optical conversion efficiency of 12%, by pumping the rod type Nd: YAG crystal by continuous wave (CW) type LD stacks. The laser power achieved by TOSHIBA Corp. is also a new world record in the field of rod type all-solid-state lasers. This report provides details of the above results and some information on future development plans.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.12 no.1
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• pp.71-81
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• 1987

To fuly utilize the availability of the ISDN, it is very important to develop the ISDN user terminals which can provide various user services. In this paper, the basic concept of the ISDN user terminal is briefly studied and, based on this study, a stimulus type digital telephone which can be connected directly to the ISDN is designed. This digital telephone can provide the basic voice service and has general functions such as voice encoding / decoding(PCM is used), user-network signalling, digital tone supply, channel selection, key pad and atatus display. Echo cancellation method is adopted for the digital subscirber loop transmission and user-network signalling is implemented according to the LAPD(Link Access Procedure on D-channel) protocol recommended by the CCITT's recommendations I.440-I.441. The validity of designed S/W and H/W functions are verified by testing them with ISDN circuit switching emulator described in the first part of this paper.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.22 no.3
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• pp.80-94
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• 2009

Objective : The purpose of this clinical research is the investigation of the effects between acupuncture group(control group) and NURIEYE-1 group (experimental group) in myopia Methods : Comparison clinical study was conducted with the randomly arranged 32 patients for acupuncture group(control group) and NURIEYE-1 group(experimental group). For effectiveness evaluation, eye sight test, MQOL and DITI were tested three times with visits for every 4 weeks. With SAS, Statistical analysis was performed by using paired t-test and two sample t-test. Statistical significance was achieved with less than 5% probability (p<0.05). Result : 1. There was no significant effect from the eye sight comparison between the two group. We had improved results in average with MQOL, however, there was no statistical significance. Though there was also no significant result with DITI average comparison between two group, we witnessed significant effect in some part of MQOL. 2. Nevertheless Periodical comparison test showed weak significance with eye sight and DITI, significant effect was found in some part of MQOL. 3. With periodical comparison tests, there were significant effects in eye sight, MQOL and DITI with the experimental groups and control groups, respectively. Conclusion : There was no significant eye sight improvement. However, with acupuncture point stimulation, we think there are some positive effects for the relaxation of excessive stress in eyes.

• Journal of Welding and Joining
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• v.34 no.3
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• pp.61-68
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• 2016

Characteristics of dissimilar metal welds between alloy steel ASTM A387 Gr. 91 and carbon steel ASTM A516 Gr.70 made with Flux cored arc welding(FCAW) have been evaluated in terms of microstructure, mechanical strength, chemical analysis by EDS as well as corrosion test. Three heat inputs of 15.0, 22.5, 30.0kJ/cm were employed to make joints of dissimilar metals with E91T1-B9C wire. Post-weld heat treatment was carried out at $750^{\circ}C$ for 2.5 h. Based on microstructural examination, tempered martensite and lower bainite were formed in first layer of weld metal. The amount of tempered martensite was decreased and the amount of lower bainite was increased with increasing heat input and layer. Heat affected zone of alloy steel showed the highest hardness due to the formation of tempered Martensite and lower Bainite. Tensile strengths of dissimilar welds decreased with increasing heat inputs. Dissimilar welds seemed to have a good hot cracking resistance due to the low HCS index below 4. The salt spray test of dissimilar metals showed that the corrosion rate increased with increasing heat inputs due to the increase of the amount of lower Bainite.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.5
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• pp.34-41
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• 2011

This paper presents a 24 channel capacitive touch sensing ASIC. This ASIC consists of analog circuit part and digital circuit part. Analog circuits convert user screen touch into electrical signal and digital circuits represent this signal change as digital data. Digital circuit also has an I2C interface for operation parameter reconfiguration from host machine. This interface guarantees the stable operation of the ASIC even against wide operation condition change. This chip is implemented with 0.18 um CMOS process. Its area is about 3 $mm^2$ and power consumption is 5.3mW. A number of EDA tools from Cadence and Synopsys are used for chip design.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.4
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• pp.355-359
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• 2014

In this paper, we proposed the new fuzzy pattern classifier which combines several fuzzy models with simple consequent parts hierarchically. The basic component of the proposed fuzzy pattern classifier with hierarchical structure is a fuzzy model with simple consequent part so that the complexity of the proposed fuzzy pattern classifier is not high. In order to analyze and divide the input space, we use Fuzzy C-Means clustering algorithm. In addition, we exploit Conditional Fuzzy C-Means clustering algorithm to analyze the sub space which is divided by Fuzzy C-Means clustering algorithm. At each clustered region, we apply a fuzzy model with simple consequent part and build the fuzzy pattern classifier with hierarchical structure. Because of the hierarchical structure of the proposed pattern classifier, the data distribution of the input space can be analyzed in the macroscopic point of view and the microscopic point of view. Finally, in order to evaluate the classification ability of the proposed pattern classifier, the machine learning data sets are used.

• Journal of Sericultural and Entomological Science
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• v.36 no.2
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• pp.147-151
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• 1994

This study was carried out investigate the characteristics of Habutae and Chiffon woven with silk and polyester(S/P) compound yarn. The S/P compound yarn could be produced by the automatic reeling machine with attachment of air jetting device, polyester yarn guider and tension control apparatus. The surface structure, tensile property and dyeing fastness of S/P compound fabric were examined for the fabric properties. Electron microscopy revealed that most part of S/P compound yarn was well interlaced and some silk part of compound yarn were hidden by polyester on an examination of surface of chiffon fabric. By the one bath and two step dyeing of disperse and acidic dyes, the colour fastness of S/P compound fabrics were 4 grade above. The tenacity and initial modulus of the finished S/P compound fabric were lower than those of grey and degummed fabrics, but reversed in elongation.

• Journal of the Korea Computer Industry Society
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• v.2 no.12
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• pp.1581-1590
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• 2001

This paper asserted more developmental model of WSD(word sense disambiguation) than J. Hur(2000)'s WSD model. This model suggested an improved statistical homonym disambiguation Model based on Bayes Theory. This paper using semantic information(co-occurrence data) obtained from definitions of part of speech(POS) tagged UMRD-S(Ulsan university Machine Readable Dictionary(Semantic Tagged)). we extracted semantic features in the context as nouns, predicates and adverbs from the definitions in the korean dictionary. In this research, we make an experiment with the accuracy of WSD system about major nine homonym nouns and new seven homonym predicates supplementary. The inner experimental result showed average accuracy of 98.32% with regard to the most Nine homonym nouns and 99.53% for the Seven homonym predicates. An Addition, we save test on Korean Information Base and ETRI's POS tagged corpus. This external experimental result showed average accuracy of 84.42% with regard to the most Nine nouns over unsupervised learning sentences from Korean Information Base and ETRI Corpus, 70.81 ％ accuracy rate for the Seven predicates from Sejong Project phrase part tagging corpus (3.5 million phrases) too.