• Proceedings of the KSR Conference
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• 2006.11b
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• pp.786-790
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• 2006

Urban rail transit offers target performance and function because various lower part system such as rolling-stock, signal, power and trackis consisted as complex. In order to function properly an urban rail transit which is complicated system to work as safety and reliability, System must secure safety with structure, design, manufacture, install and verification and it is important to establish a safety standard follows it procedures, establish what step all it is important to operate. Safety standard of urban transit infrastructure is minimum standard necessary to secure safety of signal, power and track. Urban rail transit standard business leads to make many requirements. Recently, many types of equipment have applied to manage requirements and standards for system efficiently in part of universal, airline and car accordingly applied equipments use to manage a pursuit(Trace) between standard of system. Especially importance of management is emphasized more become more. Importance of standard management which usesa computing support tool recently in transit filed is embossed and is predicted to be more such forward. Therefore we propose the effective method of management with infrastructure system by constructed data-base system.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.2
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• pp.35-42
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• 2017

The TDD LTE MU-MIMO HARQ system is designed and implemented using GPU based on 3GPP Rel.10 standard. The system consists of the DU part of the base station and the terminal using the general computer based on the GeForce GTX TITAN graphics card provided by NIVIDIA, and constructed the part of the RU using USRP N210 provided by Ettus. In the implementation part, SDR standard is applied, so that various communication standards can be compatible with software. The retransmission is implemented by combining the previous data with the retransmission data using Chase Combining among HARQ methods. In order to confirm that the retransmission was successful, the performance evaluation used LLR constellation. First, if there is an error in the data, the LLR value is not distributed at the corresponding position. in this case, a retransmission is performed to chase combine the previously stored error data and retransmitted data. As a result, the LLR value was distributed at the position of the corresponding LLR value per bit. Through this, it can be confirmed that error - free data is formed by using Chase Combining after retransmission.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.237-241
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• 2008

Femtocells are cellular access points that connect to a mobile operator's network using residential DSL or cable broadband connections. They have been developed to work with a range of different cellular standards including CDMA, GSM and UMTS. Like legacy base station, the frequency accuracy and phase alignment is necessary for ensuring the quality of service (QoS) for applications such as voice, real-time video, wireless hand-off, and data over a converged access medium at the femtocell. But, the GPS has some problem to be used at the femtocell, because it is difficult to set-up, depends on the satellite condition, and very expensive. So, some techniques are discussed to alternate with the legacy GPS system. NTP, PTP, Synchronous Ethernet use the ethernet to synchronize distributed clocks in packet networks. AGPS support reliable position information than the legacy GPS in poor signal conditions. But, These method also have some problems. So, hybrid timing method like A-GPS+PTP and TV+GPS was developed to make up the weak point of GPS. This paper introduces the each method and compare each other and y propose much better solution for timing synchronization at the Femtocell

• The Korean Journal of Food And Nutrition
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• v.24 no.1
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• pp.37-53
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• 2011

The objective of this study was to prepare the base on which Korean food can become a globally important health food. A focus group interview was conducted with a nutritionist and professor of food and nutrition to select the Korean food for a healthy menu. Five main categories were established to select a healthy menu based on the Korean food philosophy, including Korean food made from beans, Korean food made using fermentation, Korean food made using various colors, Korean food with high dietary fiber, and Korean food made with abundant unsaturated fatty acids. The 52 healthy menu items selected based on these standards were composed of easily available food materials. The efficacy of food materials described in Sikryochanyo, the traditional Chosun dietary therapy, was checked to verify the efficacy of this healthy menu. This study demonstrated that basic materials can be efficiently used to enable citizens to select Korean food as an international health food. As such, the results can be utilized to publicize Korean food as a healthy food.

• Preventive Nutrition and Food Science
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• v.3 no.2
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• pp.111-118
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• 1998

To develop a simple, rapid and simultaneous analytical method of phenolic compounds using gas chromatography (GC) and gas chromatography/mass spectrophometer (GC/Ms), this experiment was carried out to search the retention times of capillary columns and the characteristics of fragment ions in electron impact mass spectra. Most of trimethylsilyl derivatives and underivatized phenolic compounds were separated very well on three kinds of capillary columns(HP-1), Ultra-2 and HP-35). Quantitiative determination of phenolic compounds was achieved by internal standards (p-hydroxybenzoic acid iopropyl ester, p-hydroxybenzoic acid ethyl ester). Calibration plts were linear in the investigated range, and the limits of detection were about 5 ng at split mode method. When analyzed by three columns, theseparation times were fairly constant on two nonpolar columns, but a few compounds showed slightly different separation order by the itnermediate polar HP-35 column. The important characteristic patterns of TMS derivatives of phenolic compounds on the EI/MS spectrra appeared at the base peak of [M-15]+ ion and presented at high abundance in most TMS derivatives of phenoloc compounds. [M]+, [M-CH3-COO]+, [M-Si(CH3)4]+ and [M-Si(CH3)4 -CH3]+ also observed in mass spectra of these compounds . Although several compounds have the same retention times on GC column, it might be possible to identify these compounds by the different patternsof mass frgement ions. The TMS derivatives, thus , provide additional information for identification of phenolic compounds in biological systems.

• Journal of the Korean Wood Science and Technology
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• v.47 no.6
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• pp.667-673
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• 2019

The performance of a wooden deck made of refractory materials that have difficulties in achieving target penetrations as stipulated in the specification and quality standards for treated wood in Korea, was assessed via a case study in this research. A wooden deck built in Jinju in 2009 was selected for this study because of its fabrication method using pressure and treated refractory materials. The penetration and retention analysis did not satisfy the domestic standard for treated wood. Inspection of the deck in 2019 revealed that the deck had been attacked by decay fungi. Cap rails showed much deeper and wider checking on their surface compared with the top and base rails, resulting in a severe fungal attack. The decking boards exhibited severe fungal decay primarily in the end parts. However, the rails and balusters without checks and posts were virtually free of fungal attack irrespective of the preservative penetration measures. Copper content in the soil 5 cm away from the deck was less than 150 mg/kg, implying that copper movement in the soil was very limited. These results suggest that the inhibition of surface propagation and the protection of end surfaces are essential factors in increasing the longevity of treated wooden decks; further, the results also showed that the deck was within an acceptable range from the point of copper contamination.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.467-470
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• 2016

This paper deals with how to operate the sensor information through the GS1 standards in agricultural growth/distribution environment in the agricultural business. We defines the type of sensor to be used for agricultural growth / distribution environment monitor, GS1 standard identifiers for operating the sensor information, structure of the standard events, structure of schema growth / distribution environment to storage / share information and describes a method for storing, sharing information with a standard interface.

• Restorative Dentistry and Endodontics
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• v.44 no.2
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• pp.15.1-15.8
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• 2019

Objectives: The aim of this study was to investigate whether the diameter and direction of the plunger and simulation of the periodontal ligament (PDL) affected the stress distribution in endodontically treated premolars. Methods: A fracture strength test was simulated via finite element analysis. A base model was set up, and the following parameters were modified: plunger diameter (3 mm vs. 6 mm), plunger direction (vertical vs. $135^{\circ}$ angular to the central fossa), and PDL simulation. The analysis was conducted using the CosmosWorks structural analysis program, and the results are presented in terms of von Mises stresses. Results: The smaller plunger increased the stresses at the contact area of the crown, but the plunger diameter had no effect on the stress distribution within the root. An angular plunger direction increased stresses within the root, as well as at the buccal cusp of the crown, compared with the vertical direction. Simulation of the PDL caused higher stress accumulation, especially in the cervical region of the root. Conclusions: The plunger diameter had no effect on the stress distribution in the roots, whereas the plunger direction and PDL simulation did affect the stress distribution. More stringent standards can be established by taking such parameters into account when performing fracture testing in future studies.

• The Journal of the Korean dental association
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• v.57 no.9
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• pp.504-513
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• 2019

Dental education is gradually transitioning to competency-based education system, which aims to help dentists achieve certain core competencies by means of various systems, such as curriculum accreditation. This study examined satisfaction with dental school education and the differences in the perceived importance and self-assessment of competencies among general dentists, in an attempt to propose a desirable direction for dental education. A questionnaire was administered to new general dentists who graduated from a dental school within the past 10 years. The results of the survey were analyzed using the Importance-Performance Analysis to understand differences in dentists' perceptions. Overall satisfaction with education was low in terms of the curriculum's relevance to actual practice and its capacity for cultivating required competencies. Furthermore, many of the respondents strongly perceived the need to improve dental education. Additional investigations into the satisfaction with education showed no difference. Among the seven key competency domains, dentists perceived Health Promotion to be important and also assessed themselves as having high competence. However, regarding the perceived importance of the remaining domains, self-assessment of competence was low for Professionalism, Communication & Interpersonal Skills, Knowledge Base, Information Handling & Critical Thinking, Clinical Information Gathering, Diagnosis & Treatment Planning, and Establishment & Maintenance of Oral Health. The results of this study suggest that a competency-based education model should be developed and incorporated into dental education to set performance standards and to promote systematic self-assessment in order to foster the development of competence in dental students.

• Journal of Advanced Navigation Technology
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• v.25 no.3
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• pp.185-193
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• 2021

The system needs to be modified to improve the performance of the aircraft in operation or to satisfy the requirements of related laws. Appropriate standards are required for the technical skills for remodeling the aircraft system, design verification for airworthiness of the aircraft, and supplemental type certification (STC) certification procedures for type certification. This study analyzes the current status and demand of domestic aircraft remodeling, examines the current supplementary type certification procedure, and diagnoses the problem. In addition, as a result of researching measures to improve remodeling technology and certification capabilities to extend the life of the aircraft, improvements in the education system were derived to improve the domestic additional type certification process, such as approval of remodeling agencies and appointment of qualifications for each professional technician.