• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.31-40
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• 2017

This paper deals with the high precision of GPS measurement reduction and its implementation on near real-time and kinematic mode for those applications requiring centimeter-level precision of the estimated coordinates, even if target stations are a few hundred kilometers away from their references. We designed the system architecture, data streaming and processing scheme. Intensive investigation was performed to determine the characteristics of the GPS medium-range functional model, IGS infrastructure and some exemplary systems. The designed system consisted of streaming and processing units; the former automatically collects GPS data through Ntrip and IGS ultra-rapid products by FTP connection, whereas the latter handles the reduction of GPS observables on static and kinematic mode to a time series of the target stations' 3D coordinates. The data streaming unit was realized by a DOS batch file, perl script and BKG's BNC program, whereas the processing unit was implemented by definition of a process control file of BPE. To assess the functionality and precision of the positional solutions, an experiment was carried out against a network comprising seven GPS stations with baselines ranging from a few hundred up to a thousand kilometers. The results confirmed that the function of the whole system properly operated as designed, with a precision better than ${\pm}1cm$ in each of the positional component with 95% confidence level.

• Journal of Korean Library and Information Science Society
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• v.9
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• pp.63-83
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• 1982

Among many open libraries under the rule of the Japanese imperialism, only the railroad library as the character of special library under the control of the Japanese Government General is remarkable for having opened its facilities to outsiders as well as the interior users. This study tries a) To look into what were the colonial background, aim and motive of the establishment of the railroad library under the Japanese rule, b) To analyze its activities and the change of its organization, c) And to find out its vestiges an the effects which it has on our country's library circles. The following are the result: A. The railroad library under the rule of the Japanese imperialism functioned as a public library by the outside book's circulation rather than the interior using. B. The outsiders were qualified to use it only when they got the joint guarantee for the city resident, which means that the o n.0, pportunity of the circulation was not free for the Koreans rather than the Japanese. C. From the aspect of collections, technical books such as natural science, and reference ones tended to be collected, and their whole composition was focused on the materials for the Japan-Korea identification scheme and development of the national spirit as the Japanese empire's subjects. D. In the respect of its organization, all the clerical employees, as well as the chief librarian were composed of the Japanese. Although the Koreans were in principle prohibited from working there, a few of them were employed as guard or servant as the China-Japan War was close to the end. E. The area of the outside book's, circulation service was expanded throughout the whole region along the railroad connecting Pusan with Manchuria. Such a service activity which contained several meanings, was tried by means of culture's books, circuit's books, train's books, hotel's books, mind's development books and reader's reading books etc. F. Such matters as the limitation on book circulating and the quantity of circulation book, the paid circulation and the partial restriction on free circulation mean the wartime system under the rule of the Japanese imperialism and also a n.0, ppeared as a factor of hampering the Koreans from getting accustomed to using library, which has affected them until now. G. The noticeable thing in the service activity is shown in attempting the diversified and positive way of service like free circulation in order to solidify the attitude of the Koreans toward war by organizing mind's development books as well as culture's books with the China-Japan War. H. On the other hand, it can not be passed over that the diversified service activity of the railroad library played a role of bridge in turning of today's library circles of ours to the modernization.

• The korean journal of orthodontics
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• v.41 no.1
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• pp.6-15
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• 2011

Objective: The aim of this study was to evaluate the biomechanical aspects of peri-implant bone upon root contact of orthodontic microimplant. Methods: Axisymmetric finite element modeling scheme was used to analyze the compressive strength of the orthodontic microimplant (Absoanchor SH1312-7, Dentos Inc., Daegu, Korea) placed into inter-radicular bone covered by 1 mm thick cortical bone, with its apical tip contacting adjacent root surface. A stepwise analysis technique was adopted to simulate the response of peri-implant bone. Areas of the bone that were subject to higher stresses than the maximum compressive strength (in case of cancellous bone) or threshold stress of 54.8MPa, which was assumed to impair the physiological remodeling of cortical bone, were removed from the FE mesh in a stepwise manner. For comparison, a control model was analyzed which simulated normal orthodontic force of 5 N at the head of the microimplant. Results: Stresses in cancellous bone were high enough to cause mechanical failure across its entire thickness. Stresses in cortical bone were more likely to cause resorptive bone remodeling than mechanical failure. The overloaded zone, initially located at the lower part of cortical plate, proliferated upward in a positive feedback mode, unaffected by stress redistribution, until the whole thickness was engaged. Conclusions: Stresses induced around a microimplant by root contact may lead to a irreversible loss of microimplant stability.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.1
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• pp.148-156
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• 2013

This paper suggests a multi-level and multi-output SMPS based on a shared digital logic controller through independently operating in each dedicated time periods. Although the shared architecture can be devised with small area and high efficiency, it has critical drawbacks that real-time control of each DPWM generators are impossible and its output voltage can be unstable. To solve these problems, a real-time current compensation scheme is proposed as a solution. A current consumption of the core block and entire block with four driver buffers was simulated about 4.9mA and 30mA at 10MHz switching frequency and 100MHz core operating frequency. Output voltage ripple was 11 mV at 3.3V output voltage. Over/undershoot voltage was 10mV/19.6mV at 3.3V output voltage. The noise performance was simulated at 800mA and 100KHz load regulation. Core circuit can be implemented small size in $700{\mu}m{\times}800{\mu}m$ area. For the verification of proposed circuit, the simulations were carried out with Dong-bu Hitek BCD $0.35{\mu}m$ technology.

• Journal of Forest and Environmental Science
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• v.17 no.1
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• pp.47-61
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• 2001

The study was carried out to suggest the development scheme of Forestry Association by the method of member's consciousness inclination analysis. The results are as follows ; 1. Most of Association members perceived the necessity for re-education about cooperative association, especially the research suitable to the characteristics of Korea Forestry. 2. 59.9% of members had negative response against revision of Forestry Association Law, and 39.5% of members had negative opinion about taking exclusive charge of forest working by Forestry Association, noting the need of immediate publicity activities for those charges. 3. Large number of members pointed out that the most serious problems for the management of private forest were the budgetary deficit and the lack of joint marketing system of forest products. 25.9% of members had complaints about the management of their own forests after joining the association. 4. 34.0% of members opposed Proxy Management and 48.8% of members wanted Portion Consignment System. 5. The analysis noted that due to increase of the aged in rural communities, it is necessary to establish Forestry Working Corps, which is under the control of the Government and Forestry Association to supply forestry labor in a appropriate time. 6. Most of Association members liked establishment of Special Association for each forest products.

• The KIPS Transactions:PartD
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• v.9D no.2
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• pp.235-242
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• 2002

We propose an advanced transaction scheduling protocol for concurrency control of multilevel secure databases in wireless mobile network environment. Wireless communication is characterized by frequent spurious disconnections. So short-lived transaction must quickly access database without any delay by long-lived one. We adapted two-phase locking protocol, namely traditional syntax-oriented serializability notions, to multilevel secure databases in wireless mobile network environment. Altruistic locking, as an advanced protocol, has attempted to reduce delay effect associated with lock release moment by use of the idea of donation. An improved form of a1truism has also been deployed for extended a1truistic locking. This is in a way that scope of data to he early released is enlarged to include even data initially not intended to be donated. Our protocol is based on extended altruistic locking, but a new method, namely bi-directional donation locking for multilevel secure databases (MLBiDL), is additionally used in order to satisfy security requirements and concurrency. We showed the Simulation experiments that MLBiDL outperforms the other locking protocols in terms of the degree of throughput and average waiting time.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.1
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• pp.68-78
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• 2013

In this paper, we propose an early spectrum sensing(ESS) as an advance preparation for radio-access trial, which enables multi-mode terminals to access the most appropriate radio-access system in a cloud-conceptual base station system where multiple radio access technologies(RATs) coexist. Prior to a random access to one of RATs, a multi-mode terminal conducts a spectrum sensing over entire frequency bands of whole RATs, then select the RAT with the lowest sensing power, that is likely to have the most available spectrum. Thus, an access failure caused by that the selected RAT has no available radio spectrum could be avoidable in advance. In computer simulation, we consider as various RATs as possible. First, circuit and packet systems are taken into consideration. In addition, the packet systems are classified according to the feasibility of carrier aggregation(CA). In case of terminal, three modes are considered with circuit-only, packet-only, and multi-mode. Subsequently, packet traffic is classified into real-time and non-real-time traffic with three different tolerable delay levels. The simulation includes a call process starting with a call generation and ending up with a resource allocation reflecting individual user's QoS requirements and evaluates the proposed scheme in terms of the successful access probability, system access time, system balancing factor and packet loss probability.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.3
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• pp.34-41
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• 2011

This paper presents a wide tuning range, fine-resolution DCO (Digitally Controlled Oscillator) with an active inductor. In order to control the frequency of the DCO, the transconductance of the active inductor is tuned digitally. In addition, the DCO gain needs to be calibrated digitally to compensate for gain variations. To cover the wide tuning range, an automatic three-step coarse tuning scheme is proposed. The DCO total frequency tuning range is 1.4 GHz (2.1 GHz to 3.5 GHz), it is 58 % at 2.4 GHz. An effective frequency resolution is 0.14 kHz/LSB. The proposed DCO is implemented in 0.13 ${\mu}m$ CMOS process. The total power consumption is 6.6 mW from a 1.2 V supply voltage. The phase noise of the DCO output at 2.4 GHz is -120.67 dBc/Hz at 1 MHz offset.

• Culinary science and hospitality research
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• v.20 no.6
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• pp.223-234
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• 2014

The present study relates to the development of a processed product for expansion of use of Tangor which is mostly eaten raw in winter. Furthermore, Tangor jam containing fructo oligosaccharide and isomalto oligosaccharide was prepared, and thus quality characteristics of the jam have been determined according to the sugar concentration by making a low-sugar jam by adding substitute sweeteners instead of sugar, because low-sugar products are recently preferred in the market. Furthermore, the general elements of flesh and rind of Tangor, DPPH free radical scavenging activity, chromaticity, sugar content, pH, acidity, and preference have been checked. As a result of the experiment, the chromaticity, luminosity (L), the sugar content, and pH were the lowest in the control group. In F1, F2, and F3, which gradually added fructo oligosaccharide, and I1, I2, and I3, which slowly added isomalto oligosaccharide, luminosity significantly increased with the addition of oligosaccharide. In contrast, as the amount of addition of oligosaccharide increases, red chromaticity (a), yellow chromaticity (b), and sugar content have significantly decreased. Lastly, in the preference test using a 9 point test scheme, F2 and I2 have been considered most appropriate when producing Tangor jam.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.2
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• pp.113-128
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• 1990

In recent years, various types of coastal protection scheme have been studied around the coastal region. Among them, so-called zonal protection systems are being watched with interest from various points of view. In this paper, wave overtopping rate from overflowing the vertical seawall is investigated by conducting two dimensional model on the horizontal bed experiment. Hereafter this system is referred to as a artificial reef system. One is the foundation to control wave height near the surfzone and the other is function to prevent coastal disaster by suppressing net overtopping rate. The main results obtained in this study are summarized as follows. 1) Wave attenuation taken place on the artificial reef can be predicted numerically by using energy dispersion model due to wave breaking proposed by Battjes. 2) To evaluate the wave overtopping rate from a vertical seadike on various coastal constructions by weir model, a numerical procedure for prediction of overtopping is confirmed.