• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.5
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• pp.981-986
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• 2020

The Internet of Things refers to a space-of-things connection network configured to allow things with built-in sensors and communication functions to interact with people and other things, regardless of the restriction of place or time.IoT is a network developed for the purpose of services for human convenience, but the scope of its use is expanding across industries such as power transmission, energy management, and factory automation. However, the communication protocol of IoT, MQTT, is a lightweight message transmission protocol based on the push technology and has a security vulnerability, and this suggests that there are risks such as personal information infringement or industrial information leakage. To solve this problem, we designed a synchronous MQTT security channel that creates a secure channel by using the characteristic that different chaotic dynamical systems are synchronized with arbitrary values in the lightweight message transmission MQTT protocol. The communication channel we designed is a method of transmitting information to the noise channel by using characteristics such as random number similarity of chaotic signals, sensitivity to initial value, and reproducibility of signals. The encryption method synchronized with the proposed key value is a method optimized for the lightweight message transmission protocol, and if applied to the MQTT of IoT, it is believed to be effective in creating a secure channel.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.10
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• pp.1109-1116
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• 2014

The wheelchair mechanism for a car that is proposed in this study primarily consists of a transfer mechanism and storage mechanism. The wheelchair transfer mechanism consists of a manipulator installed in the roof of a car, and performs the function of transferring the wheelchair from the driver's seat to the trunk. The wheelchair storage mechanism consists of a lifting hoist installed in the trunk of car, and performs the function of storing the transferred wheelchair in the trunk and safely fastening it in place. This study analyzed and reviewed various manipulators, including a vertical type, Scara type, and telescopic type, with the goal of selecting the best type of manipulator for the wheelchair transfer mechanism. The telescopic type was selected and applied because of its good load support and storage capabilities. In addition, with regard to the wheelchair storage mechanism, a slide hoist type that used a slide rail and lift wire and a rotating link hoist type that used a rotating mechanism consisting of a worm gear and link were analyzed and reviewed. The slide hoist type was selected and applied because it had an advantage in relation to trunk space utilization. This study proposed a wheelchair transfer mechanism for a car to support a conventional wheelchair user's movements, and in order to conform to the structure of a domestic welfare car for the disabled.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.12 s.159
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• pp.1800-1809
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• 2006

The wearable technology takes the concept of clothing over its limits -integrating software, communication devices, and sensors into the garments to enable them to 'think' for the wearer. A dress is no longer just a dress, but a dress as well as a wearable computer interface. This wearable computer network transports the data power and control signals within the wearer's personal space. The purpose of this thesis is to explore the wearable technology from a commercial perspective. On this theme I made a survey and interviewed 20 men and 20 women in London to find out if many people are familiar with the concept of the wearable technology. The main results of this study include: Firstly, according to the survey, people are not familiar with the concept of the wearable technology, and further people thought negatively about the wearable computer rather than positively they worried about hish prices, inappropriate technology and side effects. Secondly, people are especially interested in items related to health and security, so in this area there are huge potential opportunities for the wearable technology, Finally, wearable technology needs to be a simplified set of interactive devices, which are in a user friendly format for marketability because convenience was one of the biggest concern for consumers. Therefore, development of the wearable computer should be promoted not only through computer engineering but also through the connection with human lift.

• Archives of design research
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• v.19 no.5 s.67
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• pp.55-64
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• 2006

As digital systems were introduced to automotive design in the mid 1980s, the design process has adopted many digital programs to save time compared to the conventional hand drafting. Digital technology was introduced not only to satisfy the reeds of the global environment, as the number of automobiles exported to many different parts of the world has increased, but also to save time and effort in developing several models of quality automobiles. Therefore, every automotive manufacturer in the world has expanded its virtual reality(VR) studio to establish visualization systems that visualize automobiles in the actual size and a co-operation system that enables simultaneous feedback from all of its design studios around the world. Unlike the existing design reviewing methos, the new improved feedback system is assessed as a reasonable method to evaluates and understand how the automobiles are actually manufactured in simulation. It is especially helpful when advanced products and concept cars require fast results. Other strengths of the new system include shorter development period, cost efficiency, no more manual labor, various designs within a short period of time, and realistic visualization of concepts. Large-scale products, including automobiles, need to be projected in the actual size and high clarity through the Power-wall System and are examined in a virtual space called a Cave. Therefore, it took much time to establish digital infrastructure. An infrastructure would constantly require system improvement and performance enhancement, but it is certain that now is the right time for the take-off to utilizing the strengths of digital design and improve the weaknesses. In this respect, this study provided an understanding of the importance of digital design based on digital reinforcements and examined an effective utilization of digital technology for an efficient development of automobiles in the future.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.10
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• pp.158-166
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• 2018

Contrary to urban development, urban regeneration is a process of land development through conservation, restoration, and management. In particular, ecologically based urban regeneration is an attempt to improve the quality of life in an area, establish a stable settlement space, and revitalize the local economy by considering the ecological environment. In this regard, the objectives of this study were to establish theoretical concepts and analyze the successful foreign cases of ecologically based urban regeneration, and propose a direction of socio-economic regeneration along with the physical-environmental regeneration of urban areas in Korea. The study results suggest the following. First, strategies must be developed to coordinate public transportation, such as buses and subways, by considering the importance of bicycle riders, along with the sustainable-commuting system. Second, both the importance of planning parks and trails around water systems in various scales while maintaining the existing natural environment as well as using natural elements, such as electric vehicles and wind-power generation systems, were emphasized. Third, urban regeneration for increased energy efficiency requires specific architectural planning and facilities. Fourth, education and research for easy access by the public, as well as public-private partnership, will be needed in the regeneration process.

• Journal of Biosystems Engineering
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• v.2 no.2
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• pp.37-45
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• 1977

Solar energy is a potential source of power that offers much promise being used for low-temperature applications like drying farm crops, space heating, and water heating for domestic uses. Already much of it are being used for those purpose in foreign countries. However, very little research has been done to determine the possibility of using the solar energy in Korea. This study was conducted to develop the general prediction equation of the total radiation on a horizontal surface in Daejeon area based on 5 years 91972, Jun.1-1976. Dec.31) meteorological data (bright sunshine hours, average total horizontal radiation), and to obtain experimentally the thermal efficiency of solar air and water collectors, which will be used as a basic data of designing flat-plate solar collector system.In addition to the thermal efficiency of the collectorsthe relationship among those factors affecting it such as weather condition, orientation factor, and tilted angle of collector was analyzed. The results of this study were as follows. 1. The general predicted equation of the total radiation on a horizontal surface in Daejeon area based on bright sunshine hours was developed as $H_{av} =(1.546\frac{n}{N}-0.582)H_o$. Predicting the total radiation on a horizontal surface by the above equation was thought to be possible because to values of 0.882 was smaller than any t values at above 0.05 level on the basis of two tailed test of the difference between the calculated and the recorded values. 2.It was observed that optimum tilt angle of the collector in the summer and the autumn drying season was 13 degrees and 51 degrees respectively, these values could be obtained by adding or substracting approximately 25 degrees from the latitude of this area $(36.3^{\circ}N)$ .The relationship between orientation factor and declination of sun at suitable tilt angle of 33 degrees $(s=0.9\O)$ was shown at Fig.4. 3.The thermal efficiency of solar wdter collector was shown 13.4-51. 6% on Aug. 15 (the minimum radiation recorded) and 43.8 ~537% Aug.20 (the maximum radiation recorded), and 13.8~ 46.6 and 44.3~ 49.7 were shown on each corresponding day. 4.The thermal efficiency of the collectors according to the weather condition was shown a big difference of about 10% between the day of the maximum radiation recorded and the minimum, but the differen of efficiency between the air and the water collector was at most 2 ~ 3%. 5. Even if the efficiency of the solar water collector was a little higher than the solar air collector, for drying farm products, the solar air collector was thought to be more effective because the air heated by collector could be directly used for drying them.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7635-7638
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• 2013

Background: Sperm-associated antigen 9 (SPAG9) has been recently proposed as a novel biomarker for early diagnosis of several human tumors, including ovarian, cervical and breast cancers. Its clinical value remains to be clarified for endometrial cancer (EC). In this study, we investigated the utility of serum SPAG9 levels in diagnosis of EC and its association with important clinicopathological parameters. Materials and Methods: This cross-sectional study was performed at a tertiary women's referral center in Ankara, Turkey. Preoperative serum samples were collected from patients surgically treated for endometrial cancer between June 2012-April 2013. Similar aged women with a biopsy proven benign endometrium were used as controls. Serum SPAG9 levels were measured with an enzyme-linked immunosorbent assay (ELISA) method and assessed for links with clinicopathological factors. Receiver operating characteristic (ROC) curve analysis was performed to assess power of SPAG9 levels for EC prediction. P values less than 0.05 were considered statistically significant. Results: A total of 63 women with EC and 27 with benign endometrium were included in the study. Mean age in the EC group was $58.7{\pm}1.1$. Median SPAG9 levels in the EC and control groups were 18.3 (range, 12.7-53.8) and 14.1 (range, 4.3-65.3), respectively (p<0.001). A cut-off value of 17 ng/ml for SPAG9 predicted presence of malignant endometrium with 74% sensitivity and 83% specificity [Area under curve (AUC)=0.82, p<0.001]. SPAG9 levels did not demonstrate any significant association with histological type, FIGO stage, tumor grade, size, myometrial invasion, lymphovascular space invasion, cervical involvement, adnexal involvement, peritoneal cytology or lymph node status (all p>0.05). Conclusions: Testing for SPAG9 may be useful for early detection of EC in asymptomatic high-risk women. Its role in post-treatment follow-up and early detection of recurrence should be assessed in future trials.

• Journal of the Korean association of regional geographers
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• v.10 no.1
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• pp.67-82
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• 2004

There is a general agreement that the global social-economic system is undergoing fundamental changes, which can be explained in terms of the transformation of production system from the Fordism to Post-Fordism since the 1980s. These fundamental changes have resulted in the 'new urbanization' process in the most of large cities in the developed countries. The aim of this paper is to identify the 'new urbanization' process in a large city in Korea that is, Daejon. For the propose, this paper tries to examine and conceptualize empirically the changes of economic, political, social-cultural, and spatial aspects of Daejon metropolis in the respect of 'new urbanization'. The major findings of this essay are summarized as follows. First of all, Daejon economy has experienced new changes, that is the development of service economy and high tech industry. But the old industry still remain important in the urban economy. Secondly, in the political aspect, new civil movements flourish in the city, while the political power of Jaminlyeon, a pro-conservative and narrow-regionalism party, once dominated this region, has decreased its influence. Thirdly. the original CBD of Daejon has been declined while new (sub-)CBBs have emerging in Daejon spatial structures. In conclusion, we can find some clues of the new urbanization process in Daejon, but this process is still quite slow and somewhat different from those of large cities of the developed countries.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.05a
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• pp.254-260
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• 1999

Meteor Burst Communication can provide effective and economical means of communication where long distance VHF NLOS data transmission is needed; often ranges more than 1000 km. It has been, however, so far considered unsuitable for short distance application because of phenomenal decrease in burst durations, which leads to decreation of total duty rate of the system. This paper extensively analyzes characteristics of shot distance MB(Meteor Burst) path and shows the low duty rate may be improved by increasing burst rate through adapting antenna beam width to cover entire hot-spot region in the space and, by compensating effective burst length through cutting down man-made noises introduced by antenna. Based on the analysis, we are developed a small-opening-cavity antenna, especially designed for short distance MB path. In operation, the antenna is to be buried under ground surface so as to improve directivity and reduces noise introduction. The antenna exhibits power gain of 3 dB with 90 degree beam width and thus enables to illuminate entire hot-spot regions with the elevation angle of 8-90 degree which is the case of transmission less than 100 km. Directivity horizontal to earth surface is suppressed to minimum which enables to cut man-made noises from near-by sources down to more than 3 dB from the level reported with conventional 4 element Yagi. A series of experiments performed on 100 km MB paths have conformed that, with the antenna installed at receiving site, the burst rate and duration time have been noticed to increase by 10 and 20 percent respectively from the values obtained by conventional 4-element Yagi antenna under same testing condition.

• Journal of Korean Library and Information Science Society
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• v.9
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• pp.115-144
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• 1982

In ordinary modern wester expression 'the Renaissance' was used to denote the impact made by dead Hellenism civilization in western Christendom, particularly Italian literary and artistic movement at Northern and central Italy in the late medieval period. However, A.J. Toynbee examined the renaissance from the different aspect of view. In his great work "A Study of History" in vol. IX, he succeeded in establishing the theory of historic civilization encounters in space and in time; and in time, civilization of the present and the past or between dead and infant successor contacts on the analogy of parenthood and sonship in the relation of A n.0, pparentation-and-Affiliation. The distinguished his view of 'Renaissance' was illustrated in the sense of encounters between a grown-up civilization and the 'ghost' of its long-dead predecessor. The renaissances (by the process of evocation of ghost of its parent society) has not only one single aspect of literary and artistic field but also in politics, law, science and philosophy, languages and literatures and visual arts, and religion. The main theme of this study is to examine the development of libraries and its historical meaning through Toynbee's literary renaissance. His renaissance of Languages and Literatures has three typical steps: They are: 1st step-to restive the dead literature's remains: 2nd step-to remaster their meaning: 3rd step-to reproduce them in counterfeits... Through its first and second steps, collecting and editing, annotating by compiling an anthology, thesaurus, lexicon or encyclopedia, and in its third step publishing mostly imitation of classics took place. Toynbee depicted the five outstanding eminent representatives of literary renaissance who had a n.0, ppeared on the state of history down to the time of writing. They are: Assurbanipal, Constantine prophyrogenitus, Yung Lo, K'ang Hsi, and Ch'ien Lung and the last four had all been emperors of imperia rediviva. As the result of the examination of these five emperors with three steps of literary renaissance, the common result may be summarized as follows: 1. Those emperors of imperia rediviva interested in intellectual work and study, they also were deeply involved in collecting classics in an ostensible reason. 2. There were strong political intention of collecting materials as an a n.0, ppeasement policy of civilization by transferring scholars energies to an intellectual field. 3. Under the rulers of a resuscitated universal state, the literary renaissance were a product of political plane and that the total size of collection and work were huge. 4. Since there were strong exercise of sovereign power, an active censorship by distortion and elimination was inevitable. 5. There existed newly developed strained atmosphere between grown-up and long-dead parent civilization, whenever the book collection movement had occurred. 6. Over adhesion to the parent civilization caused imitation of classic work and the creative activities were stagnated.stagnated.