• Journal of Soil and Groundwater Environment
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• v.29 no.4
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• pp.12-20
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• 2024

Diffusive gradients in thin films (DGT) are passive sampling devices used to determine the time-weighted average concentrations (TWAC) of contaminants. To ensure accurate performance in groundwater, it is crucial to identify environmental characteristics and maintain optimal operational conditions. This study examined the deployment time required to reach effective capacity, the thickness of the diffusive boundary layer (DBL) under stagnant water conditions, and biofilm formation on the DGT surface using groundwater samples. When using DGT with Chelex gel (A=3.14 cm²), the effective capacity was 0.7 ㎍ for Cd and 250 ㎍ for Zn, with a deployment time of 24 h. Lower Cd accumulation was due to the competition effect of coexisting ions. The DBL thickness under stagnant conditions was 0.074 cm, 93% of the diffusion gel's thickness (0.08 cm). Neglecting DBL thickness in TWAC calculations led to a 79% decrease in the determined concentration. No biofouling was observed during the 28-d DGT deployment in groundwater. In conclusion, it is essential to consider the appropriate deployment time, DBL thickness, and biofilm formation to ensure accurate DGT performance in determining contaminant levels in groundwater.

• Clinical and Experimental Pediatrics
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• v.51 no.9
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• pp.992-997
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• 2008

Purpose : Hypertension (HTN) is no longer an exclusively adult disease; the prevalence of pediatric HTN is increasing. To understand the evaluation and treatment of childhood HTN in Korea, we investigated, via a questionnaire, how hypertensive children are currently assessed and managed by pediatric cardiologists (CA) and nephrologists (NE). Methods : We surveyed 82 pediatric CA and 77 NE, regarding how they manage hypertensive children in Korea. Results : A total 75 replies were received to our questionnaire request (response rate: 47.15%). Routine blood pressure (BP) checks were more frequently performed by NE (CA: 5.7%, NE: 25%, P=0.03), but most respondents (86%) did not check BP routinely. Mercury sphygmomanometers were the most commonly used devices and ambulatory blood pressure monitoring was not frequently used. The goal BP in treated patients was set at the 95th percentile by 61% of respondents. NE used a lower BP goal in hypertensive children with renal disease (CA: 24%, NE: 64%, P=0.004) or DM (CA: 12.5%, NE: 50%, P=0.003). Angiotensin converting enzyme (ACE) inhibitors were the most commonly used agents (mean: 59%); following ACE inhibitors, CA preferred diuretics for hypertensive children with renal disease or cardiovascular disease, and NE preferred calcium channel blockers, regardless of underlying disease. Self-monitoring was the most frequent method for BP monitoring at home. Conclusion : In Korea, BP measurement is not yet a routine examination in treating hypertension. There are some differences in management strategies vis-$\grave{a}$-vis hypertension, between pediatric cardiologists and nephrologists. For the appropriate management and prevention of secondary disease in long-term studies, standard guidelines and education are needed for pediatricians.

• Journal of The Korean Dental Society of Anesthesiology
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• v.14 no.1
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• pp.29-39
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• 2014

Background: Dental phobia or anxiety of patients is the serious impediment to appropriate and effective dental treatment. Sedative technique helps to mitigate patients' fear and anxiety thus make them more cooperative and familiar to dental practices. With increasing attention to sedative dentistry in dentists, educational requirements and technical qualification also become stricter but actual survey on recent sedative dentistry has not been reported yet. Especially there is insufficient study reporting the survey of sedative dentistry subjected to Korean adults. In this paper, we conducted a survey study on the actual condition and practice related to sedation with a questionnaire to dentists in South Korea. Methods: The survey was done for members of The Korean Dental Society of Anesthesiology (KDSA), who had great interest in sedation and for whom survey-by-mail was convenient. 472 members of The KDSA having dental license and solid address and contact information were subjected to the survey by sending them survey questions about their sedative techniques and knowledge. In order to increase the response rate, small gifts were presented to those who accurately responded to the survey questions and text messages and phone calls were made to encourage their participation. We collected their responses over two months and examined the returned surveys. Statistical analysis was performed using IBM SPSS Statistics 21 for each question. Results: Out of 472 dentists, 181 responded (38.4% response rate). 63.0% (114 dentists; 77 male and 37 female) of respondents had experience on sedative technique and their average age was $39.8{\pm}7.6$ year. 74 of them were private practitioners, 17 of them were professors (14.9%), 11 of them were dentists-in-service (9.6%), 11 of them were residents (specialist training) (9.6%) and 1 of them was military doctors (0.9%). There were 89 dentists (78.1%) who were specialists or receiving trainings to be specialist, most of whom were pediatric dentists (55, 48.2%) and oral surgeon (31, 27.2%). The most popular route for drug medications was orderly oral, inhalational, intravenous medication. Combination of oral and inhalational medications or single use of intravenous medication was the most common. The most preferred sedative drug was pocral in oral sedation and midazolam in intravenous sedation. 48.2% of practitioners responded that they experienced side effects and emergency situations. Airway obstruction was the most frequent. Conclusions: Results from the survey show that the protocol and system for sedative dentistry have been improved compared to the past. Nevertheless, quality of emergency protocol, monitoring devices and preparation of sedative drugs was still insufficient to achieve safe sedative procedure. This study acquires novelty since actual survey on recent sedative dentistry for adult patients has not been reported yet.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.7
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• pp.87-94
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• 2019

Recently, the advance of accurate dynamic displacement measurement devices, such as GPS, computer vision, and optic laser sensor, has enhanced the structural monitoring technology. In this study, the dynamic displacement data was used to verify the applicability of the structural physical parameter estimation method through subspace system identification. The subspace system identification theory for estimating state-space model from measured data and physics-based interpretation for deriving the physical parameter of the estimated system are presented. Three-degree-freedom steel structures were fabricated for the experimental verification of the theory in this study. Laser displacement sensor and accelerometer were used to measure the displacement data of each floor and the acceleration data of the shaking table. Discrete state-space model generated from measured data was verified for precision. The discrete state-space model generated from the measured data extracted the floor stiffness of the building after accuracy verification. In addition, based on the story stiffness extracted from the state space model, five column stiffening and damage samples were set up to extract the change rate of story stiffness for each sample. As a result, in case of reinforcement and damage under the same condition, the stiffness change showed a high matching rate.

• Journal of Internet Computing and Services
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• v.17 no.5
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• pp.59-65
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• 2016

Recently, a study has been progressed about the energy storage system for resolving energy shortage problems in the world. The energy storage system can maximize energy storage system's energy usage by monitoring and controlling about all energy infrastructures on energy network. However, compatibility problems among main components or devices of the energy storage system are obstacles to development of energy storage system products. An extensible profile and extensible profile verification software being able to verify the extensible profile have been required in order to resolve compatibility problems. In this paper, the study on complexity analysis for the extensible profile verification software for the energy storage system is performed. A XML based profile and C language structure based profile are used for analysis of the profile verification software. The complexity of complex verification structure that parses the XML based profile several times and simple verification structure that parses the C language structure based profile are analyzed and compared. Time complexity, space complexity, and cyclomatic complexity are used for complexity analysis. By using these complexity analysis, the study result that compares and analyzes the complexity of XML based and C language structure based profile verification software is presented.

• Journal of Korea Multimedia Society
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• v.10 no.10
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• pp.1347-1355
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• 2007

A sensor network is composed of a large number of tiny devices, scattered and deployed in a specified regions. Each sensing device has processing and wireless communication capabilities, which enable it to gather information from the sensing area and to transfer report messages to a base station. The energy-efficient routing paths are established when the base station requests a query, since each node has several characteristics such as low-power, constrained energy, and limited capacity. The established paths are recovered while minimizing the total transmit energy and maximizing the network lifetime when the paths are broken. In this paper, we propose a routing algorithm that each sensor node reports its adjacent link information to the sink node when a sink node broadcasts a query. The sink node manages the total topology and establishes routing paths. This algorithm has a benefit to find an alternative path by reducing the negotiating messages for establishing paths when the established paths are broken. To reduce the overhead of collection information, each node has a link information before reporting to the sink. Because the node recognizes which nodes are adjacent. The proposed algorithm reduces the number of required messages, because sensor nodes receive and report routing messages for establishment at the beginning of configuring routing paths, since each node keeps topology information to establish a routing path, which is useful to report sensing tasks in monitoring environments.

• The Journal of the Korea Contents Association
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• v.14 no.5
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• pp.211-223
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• 2014

The aim of this study was to identify the levels of family members' burden and to describe factors influencing on famiCX*//8ly caregiver's burden when they are planned to transfer to general ward from the intensive care units (ICU). A descriptive survey was used with a convenience sampling of 101 family members of ICU patients at S university hospital in C city, Korea from August to November, 2010. The data were analyzed with SPSS 18.0 program. The level of object burden in family members had statistically significant differences with level of consciousness, number of patients' monitoring devices, and tracheostomy tube. The level of subject burden had statistically significant differences according to patients' gender, patients' education level, and relationship with patients. Transfer anxiety was showed statistically positive correlation with objective and subjective burden. We found transfer anxiety was statistically significant predictor of family caregiver's objective burden with explanatory power 12.7%. Family members' subjective burden were statistically influenced by patients' gender and transfer anxiety. These factors explained 23.8% out of total variance of family members' objective burden. The structured individualized method of transfer is recommended with further research of ICU families to further examine the dimension of transfer anxiety and how it affects family members' burden and patient outcomes.

• Korean Security Journal
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• no.13
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• pp.113-144
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• 2007

The entire world has lived in terror threatened by new-terrorism since the 9.11 terror. Having appeared since 9.11, new-terrorism is new kind of terror targeting victims at random. Bioterrorism is one good example. Since bioterrorism happens secretly, it's hard to identify. The case becomes even harder to detect if it takes the form of a new epidemic. This study set out to apply the four phases of crisis management regarding outbreak and measures of SARS, the latest new epidemic, and to prepare against bioterrorism taking the form of a new epidemic, It also shows the efforts to study what to prepare and what kind of actions to take in case of bioterrorism by applying the four phases. There results demonstrate that the preventive measures against bioterrorism include arranging terror-related laws and identifying and monitoring expected pathogenic organs. In the preparation phases, they should integrate the related agencies, prepare for the standard operating procedures(SOP), execute integrated training sessions among the related agencies, and secure the necessary resources such as vaccine, cures, and exploration devices. In the response phases, they need to set up a rapid diagnosis system, quarantine and then cure the patients, and pursue cooperation from the media and promotions and further an international cooperation system to take appropriate measures. And the final recovery phases should involve offering emergency support by checking the situations and engaging in activities to prevent another terror attack by providing counseling, exchanging information, and analyzing and evaluating the causes.

• Journal of Satellite, Information and Communications
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• v.1 no.2
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• pp.95-100
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• 2006

The COMS(Communication, Ocean and Meteorological Satellite) EPS(Electrical Power Subsystem) is derived from an enhanced Eurostar 3000 version. Eurostar 3000 EpS is fully autonomous operation in nominal conditions or in the event of a failure and provides a high level of reconfigure capability. This paper introduces the COMS EPS preliminary design result. COMS EPS consists of a battery, a solar arrat wing, a PSR(Power Supply Regulator), a PRU(Pyrotechnic Unit), a SDAM(Solar Array Drive Mechanism) and relay and fuse brackets. COMS EPS can offer a bus power capability of 3 kW. The solar array is made of a deployable wing with two panels. One type fo solar cells is selected ad GaAs/Ge triple junction cells. Li-ion battery is base lined with ten series cell module of five cells in parallel. PSR associated to battery and solar array wing generates a power bus fully regulated at 50 V. Power bus os centralized protection and distribution by relay and fuse brackets. PRU provides power for firing actuarors devices. The solar array wing is rotated by the SADM under control of the attitude orbit control subsystem. The control and monitoring of the EPS, especially of the battery, is performed by the PSR in combination with the on-board software.

• Journal of Korea Society of Industrial Information Systems
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• v.19 no.1
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• pp.13-18
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• 2014

Sensor nodes are used for monitoring and collecting the environmental data via wireless sensor network. The wireless sensor network with various sensor nodes draws attention as a key technology in ubiquitous computing. Sensor nodes has very small memory capacity and limited power resource. Thus, it is essential to have energy efficient strategy for the sensor nodes. Since the sensor nodes are operating on the same frequency bands with ISM frequency bands, the interference by the devices operating on the ISM band degrades the quality of communication integrity. In this paper, the convolutional code is proposed instead of ARQ for the error control for the sensor network. The proposed convolutional code was implemented and the BER performance is measured. For the fixed transmitting powers of -19.2 dBm and -25dBm, the BER with various communication distances are measured. The packet loss rate and the retransmission rate are calculated from the measured BER. It is shown that the porposed method obtained about 9~12% and 12-19% reduction in retransmission rate for -19.2 dBm and -25 dBm respectively.