• Journal of Conservation Science
• /
• v.29 no.4
• /
• pp.421-435
• /
• 2013

The purpose of this study is to suggest environmental guidelines for the conservation of ceramics excavated from underwater. Accordingly, the conditional change of the soluble salt on surface of the excavated ceramics was examined by changing the relative humidity. Examining the relative ratio [high humidity(RH70%+RH80%)/low humidity(RH20%+ RH40%)] for 24 weeks using accumulated conductivity(${\mu}s/cm$), the result showed that the amount of ion elution increased more in high humidity than in low humidity. In particular, the ion elution increased significantly within the celadon sample. In addition, comparing the accumulated conductivity and physical characteristics of the samples in high humidity, the results indicated that the amount of the ion elution is proportioned to the increased rate of the sample's absorption capacity and porosity. Ceramics excavated from underwater has risks of the secondary physical and chemical attacks from remaining salts. Therefore, it is suggested these ceramics be stored in a storage which maintains proper temperature and low humidity conditions. Also, the collections need to be pre-classified according to the properties of the materials.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.16 no.11
• /
• pp.1037-1053
• /
• 1991

Flooding is known to be an effective routing mechanism not only in circuit switched networks but also packet switched networks since it minimizes the time required for up calls and does not have to maintain routing tables or distance tables by periodically intercommunicating among all the network nodes. However, one main drawback of it is the overhead on the control message signaling channels, In the paper, we propose an overlaying scheme on the existing mechanism that retains the desired properties of flooding, yet provides congestion control to the network. This is done by utilizing the wasted search messages to inform the network of the conditions of each path from one node to another. The overhead is to maintain a path table in each node. However, this overhead is not so critical. Also, this scheme can take advantages further by limiting the extent of message propagation through the network and by incorporating trunk reservation schemes additionally.

• Korean Journal of Medicinal Crop Science
• /
• v.10 no.1
• /
• pp.1-4
• /
• 2002

This study was carried out to know the effect of light intensity, temperature and $CO_2$ concentration on photosynthesis and transpiration in Hovenia dulcis Thunb. Light compensation point was $2.4\;{\mu}mol\;m^{-2}\;s^{-1}$ and light saturation point was $1033\;{\mu}mol\;m^{-2}\;s^{-1}$. The optimum temperature for photosynthesis was $25^{\circ}C$ at $1000\;{\mu}mol\;m^{-2}\;s^{-1}$ light intensity. $CO_2$ compensation point was 67 vpm and $CO_2$ saturation point was 707 vpm. Transpiration rate was increased to about $2\;mmol\;m^{-2}\;s^{-1}$ with increasing of light intensity to $1750\;{\mu}mol\;m^{-2}\;s^{-1}$ and to above $4\;mmol\;m^{-2}\;s^{-1}$ with increasing of temperature from $18^{\circ}C$ to $36^{\circ}C$. however It was gradually reduced as $CO_2$ concentration increased from 21 vpm to 800 vpm.

• Smart Media Journal
• /
• v.1 no.4
• /
• pp.52-58
• /
• 2012

In recent years the combination of IT and BT for U-Healthcare Medical Services has attracted popular attention as an alternative for solving health problems due to aging issue. Active oxygen as free radicals causes unstable state of the body resulting to other disease on which approximate 90% of the diseases are associated with active oxygen. The severity is even higher along with increasing age. Therefore, there is a need for systematic management of active oxygen saturation for the elderly and chronic patients. In this paper, the data about active oxygen measurements from the body measurement is sent to the data storage of medical facilities by the service provider. Medical information is measured by devices provided complying with the standard, support and information using Bluetooth communication. Users can check their health status themselves using the proposed system through 3G/4G mobile devices like smart phone to medical institutions in which the smart phone act as a gateway for medical data transferred from patient to medical institutions and vice versa. Users can get and experience a diagnosis and effective U-Environmental Health Services from Medical institutions anywhere using the proposed built system.

• The Journal of Engineering Geology
• /
• v.25 no.4
• /
• pp.511-524
• /
• 2015

Groundwater causing subsidence in limestone mines is uncommon, and thus relatively poorly investigated. This case study investigated the cause and possibility of future subsidence through an evaluation of ground stability at the Samsung limestone mine, Chungcheongbuk-do. The ground near the mine area was evaluated as unstable due to rainfall permeation, and subsidence in the unmined area resulted from groundwater level drawdown. Future subsidence might occur through the diffusion of subsidence resulting from the small thickness of the mined rock roof, fracture rock joints, and poor ground conditions around the mine. In addition, the risk of additional subsidence by limestone sinkage in corrosion cavities, groundwater level drawdown due to artificial pumping, and rainfall permeation in the limestone zone necessitates reinforcements and other preventative measures.

• Journal of Korean Society of Transportation
• /
• v.21 no.4
• /
• pp.79-90
• /
• 2003

Internal metering policy(IMP) is a control strategy to improve the quality of traffic flow within a network by avoiding queue spillback or intersection blockage. It is a more aggressive control strategy than the current control strategy employed in COSMOS. A preliminary study was made to incorporate the IMP logic within the COSMOS system to improve its' functionality at oversaturated conditions. From the study results, a set of guideline for real implementation was recommended : traffic conditions, detector configurations, and control procedures, etc. A simulation study was performed to evaluate the effectiveness of the proposed guidelines. It was shown that the occurrence of queue spillback was minimized. and overall network performance was also improved by applying IMP logic as compared to COSMOS control onl.

• Journal of Korean Society of Transportation
• /
• v.27 no.5
• /
• pp.125-134
• /
• 2009

Recently, as IT technology and the ubiquitous environment have diffused, the application of these techniques are being attempted in the field of traffic operations and management. Therefore, it is necessary to develop data collection systems and signal control strategies that are suitable in the ubiquitous environment and that will improve efficiency and safety of signalized intersections. The authors conducted a study on the Wireless Sensor Network (WSN) signal control strategy using a wireless communication network between individual vehicles and a signal-control system and full actuated signal control technique to propose a new signal control strategy in the ubiquitous environment. The WSN was defined to evaluate the algorithm used with PARAMICS API simulation. The simulation produced results that the WSN signal control is more effective than other signal control methods. The WSN signal control could reduce vehicle delay time to a maximum of 64% in comparison with other signal control methods in low and near saturation flow conditions.

• Journal of the Korean Society for Library and Information Science
• /
• v.56 no.1
• /
• pp.347-364
• /
• 2022

The purpose of this study is to propose a method of calculating the shelves required for the placement of bookshelves in the school library. The study was conducted by visiting 11 school libraries, and current library status was identified according to school levels and major subjects of the Korean Decimal Classification. According to the results of the survey, ideal numbers of arranged volumes are 46.9, 32.3, and 28.4 volumes of books, for elementary, middle, and, high school respectively, which takes up 67 percent of a 90-centimeter-unit bookshelf. However, the more realistic number turned out to be 75%, with 52.8, 36.4, and 32.0 volumes of books for elementary, middle, and high schools, respectively. Based on the results of the survey, a tool was presented to calculate required bookshelves in school libraries. This study is expected to have a positive impact on library operation by making it easier to calculate the bookshelves required for actual placement.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.20 no.3
• /
• pp.195-200
• /
• 2020

Wireless LANs are being used in many fields due to their ease of use. The biggest advantage of the WLAN can be said above all mobility. Domestic wired internet service has been saturated since 2006, but wireless internet users have been steadily increasing. However, WLAN has many advantages and characteristics of wireless service. It has a number of security vulnerabilities, and various security related technologies have been developed and applied to solve these problems. On the other hand, security awareness of WLAN users is still insufficient, and security accidents such as personal information leakage occur repeatedly every year. We will study the main weaknesses that can occur in WLAN and suggest security measures from the management level.

• 전자공학회논문지 IE
• /
• v.49 no.2
• /
• pp.82-88
• /
• 2012

In this paper, using the Android-based mobile platform designed and integrated U-healthcare systems for personal health care system is proposed. Integrated Biometric systems, electrocardiogram (ECG), oxygen saturation, blood pressure, respiration, body temperature, such as measuring vital signs throughout the module and signal processing biometric information through wireless communication module based on the Android mobile platform is transmitted to the gateway. Biometric data transmitted from a mobile health monitoring system, or transmitted to the server of U-healthcare was designed. By implementing vital signs monitoring system has been measured in vivo by monitoring data to determine current health status of caregivers had the advantage of being able to guarantee mobility respectively. This system is designed as personal health management and monitoring system for emergency patients will be helpful in the development looks U-healthcare system.