• Korean Security Journal
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• no.62
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• pp.347-367
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• 2020

Rapid advancement of technology in today's society has allowed for easy access and use of data, promoting the process of informationization. Along with the merits of such development, unintended consequences of security risks involving wiretapping have been increasing as well. The security threats posed by wiretapping technology must be addressed by every organization and individual, as it could be used to leak confidential information about the nation's security, military and diplomatic strategies, industrial technologies, and personal information. Despite increasing threats stemming from the surrounding nations using advanced wiretapping technology, there is a lack of awareness at the government level, and the existing security measures for detecting and counteracting the wiretapping equipment are ineffective. In this research, the authors offered technical suggestions for improving the security strategies against the threats of wiretapping and information leakage by conducting a content analysis. The authors suggested the units of an agency be assigned a security grade based on its importance, and that adequate security equipment should be operated according to the grade. For instance, around-the-clock surveillance is recommended for grade-1 facilities, and portable wiretapping equipment detectors should be used to protect conference rooms and other key sites.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.4
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• pp.1479-1487
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• 2013

The river levee collapse and flood damages are dramatically increased due to the floods which caused by abnormal weather nowadays. The counterplan like TDR(Time Domain Reflectometry) river levee leaking exploration technique is needed to that levee failure causes of levee failure such as levee failure by penetration, piping, inadequate levee materials selection, poor compaction are almost 52% of the failure. This research practiced various comparing experiments of existing TDR(probe and tube types) and developing CAP type TDR to evaluate acrylic small CAP mould and low-cost TDR levee leaking monitoring system which was used probe type TDR. As the result, evaluated TDR system had 20cm critical exploration performance which was a leaking exploration performance, The functional ratio of TDR exploration sensitivity of dry density was sensitive more than 3 times than dry density, and weathered granite soil foundation water contents(w)-dielectric constant(${\epsilon}$) corelation formula was suggested to measure functional ratio on developing cap type TDR system.

• Journal of the Korea Safety Management & Science
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• v.17 no.4
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• pp.297-304
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• 2015

This study concerns the integrated gas sensor system of wire and wireless communication by using IoT(Internet of Things) technology. First, communication part is that it delivers the detection information, which transferred by wire or wireless communication and required control procedure based on a wireless module that receives the gas leakage information from wired or wireless detector, to administrator or user's terminal. Second, receiver part is that it shows the location and information, which received from the wired detector formed by a detecting sensor's node as linking with the communication part, and transfers these to the communication part. Third, wireless detector formed as a communication module of a detecting sensor node is that it detects gas leakage and transfers the information through wireless as a packet.Fourth, wired detector communicated with the receiver part and formed as a communication module of a detecting sensor node is that it detects gas leakage, transfers and shows the information as a packet. Fifth, administrator's terminal is that it receives gas leakage information by the communication part, transfers the signal by remote-control, and shut off a gas valve as responding the information. Sixth, database is that it is connected with the communication part; it sets and stores the default values for detecting smoke, CO., and temperature; it transfers this information to the communication part or sends a gas detecting signal to user's terminal. Seventh, user's terminal is that it receives each location's default value which stored and set at the database; it manages emergency situation as shutting off a gas valve through remote control by corresponding each location's gas leakage information, which transferred from the detector to the communication part by wireless.It is possible to process a high quality data regarding flammable or toxic gas by transferring the data, which measured by a sensor module of detector, to the communication part through wire and wireless. And, it allows a user to find the location by a smart phone where gas leaks. Eventually, it minimizes human life or property loss by having stability on gas leakage as well as corresponding each location's information quickly.

• Tuberculosis and Respiratory Diseases
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• v.54 no.5
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• pp.532-541
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• 2003

Background : Phospholipase $A_2$ ($PLA_2$) has been known to be involved in the pathogenesis of acute lung injury (ALI) including ARDS. Since doxycycline has the property of inhibiting secretory group II $PLA_2$, the therapeutic effect of doxycycline hyclate was investigated for gut ischemia/reperfusion (I/R)-induced ALI in Sprague-Dawley rats. Methods : ALI was induced in Sprague-Dawley rats by clamping of the superior mesenteric artery for 60 min, followed by 120 min of reperfusion. To confirm the pathogenetic mechanisms of this ALI associated with neutrophilic oxidative stress, we measured bronchoalveolar lavage (BAL) protein content and lung MPO, and performed cyto-chemical electron microscopy for detection of free radicals, assay of $PLA_2$ activity and cytochrome-c reduction assay. Results : In gut I/R-induced ALI rats, protein leakage, pulmonary neutrophil accumulation, free radical production and lung $PLA_2$ activity were all increased. These effects were reversed by doxycycline hyclate. Conclusion : Doxycycline appears to be effective in ameliorating the gut I/R-induced ALI by inhibiting $PLA_2$, thereby decreasing the production of free radicals from neutrophils.

• Journal of the Korean GEO-environmental Society
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• v.22 no.11
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• pp.31-37
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• 2021

To prevent accidents due to the cavities and loosened layers formed due to water leakage from the deteriorated buried pipes, evaluation of the changes in water contents around the buried pipes is required. As a method to evaluate the water contents of the soils, time domain reflectometry (TDR) system can be adopted. However, slender electrodes used in standard TDR probe may be damaged when buried in the ground. Thus, in this study, buried type TDR module was developed for the evaluation of the water contents with maintaining required shape of the electrodes in the ground. The TDR module is composed of three electrodes connected to the core conductor and outer conductor and a casing to prevent deformation and maintain alignment of the electrodes in the ground. For the verification of TDR waveforms measured using the TDR module, comparative analysis was conducted with the TDR waveforms measured using the standard TDR probe, and the relationship between the volumetric water content of the soils and the travel time of the guided electromagnetic wave was constructed. In addition, a model test was conducted to test the applicability of the buried type TDR module, and the experimental result shows that the TDR module clearly evaluates the changes in volumetric water contents due to the leakage from the modeled buried pipe. Therefore, the buried type TDR module may be effectively used for the health monitoring of the buried pipe and the evaluation of the water contents around the pipes buried in the urban pavements.

• Journal of the Korean Society for Environmental Technology
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• v.19 no.6
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• pp.576-585
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• 2018

Systematic management during the whole life cycle from construction to operation and maintenance is very important for the seven underground pipelines (waterworks, sewerage, electricity, telecommunications, gas, heating, oil including waterworks and sewerage). Especially, it is the construction process that affects the whole life cycle of underground buried pipeline. In order to construct a new city or to maintain different underground pipes, it is always necessary to dig the ground and carry out construction and related work. There is a possibility that secondary and tertiary breaks frequently occur in the pipeline construction process after the piping constructed first in this process. To solve this problem, a system is needed which can monitor damage in real time. However, the supply of electric power for continuous operation of the system is limited according to the environment of underground buried pipelines, so it is necessary to develop a stable electric power supply system using natural energy rather than existing electric power. In this study, we developed a system that can operate the pipeline monitoring system for long time (24 hours and 15 days) using natural energy using wind and solar light.

• Korean Chemical Engineering Research
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• v.59 no.1
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• pp.68-76
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• 2021

As hazardous chemicals are releasing in process industries such as chemical & petro-chemical plants, the importance of initial responses has been always emphasized. However, little attention of quantitative analysis of the consequence by different initial responses during releasing of the chemicals has been done. The main objective of current paper is to investigate the effects of initial responses for the release accidents of hydrofluoric acid. For this, a simplified equation that can easily calculate the effect distance by varying concentrations of hydrofluoric acid was firstly deduced. In addition, a causal loops for the initial response steps using the system dynamics technique was constructed during release of 50% hydrofluoric acid. The effect distances according to different scenarios of the initial actions were also quantitatively analyzed by applying the simplified equation to the causal map. As a result, the highest reduction rate on the maximum effect distance was obtained with 'start time of action after leak detection' being about 87% while the lowest was 'arrival time of professional response team' being about 50%, as expected. It is expected that the results gained from the current study can be helpful as of basics of the initial response to the workplace, dealing with the hydrofluoric acid.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.7
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• pp.964-970
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• 2023

As part of the International Maritime Organization ef orts to reduce greenhouse gas emissions, the maritime industry is exploring low-carbon fuels such as liquefied natural gas and methanol, as well as zero-carbon fuels such as hydrogen and ammonia, evaluating them as environmentally friendly alternatives. Particularly, ammonia has substantial operational experience as cargo on transport ships, and ammonia ship engines are expected to be available in the second half of 2024, making it relatively accessible for commercial use. However, overcoming the toxicity challenges associated with using ammonia as a fuel is imperative. Detection is possible at levels as low as 5 ppm through olfactory senses, and exposure to concentrations exceeding 300 ppm for more than 30 min can result in irreparable harm. Using the KORA program provided by the Chemical Safety Agency, an assessment of the potential risks arising from leaks during ammonia bunkering was conducted. A 1-min leak could lead to a 5 ppm impact within a radius of approximately 7.5 km, affecting key areas in Busan, a major city. Furthermore, the potentially lethal concentration of 300 ppm could have severe consequences in densely populated areas and schools near the bunkering site. Therefore, given the absence of regulations related to ammonia bunkering, the potential for widespread toxicity from even minor leaks highlights the requirement for the development of legislation. Establishing an integrated system involving local governments, fire departments, and environmental agencies is crucial for addressing the potential impacts and ensuring the safety of ammonia bunkering operations.

• Fiber Technology and Industry
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• v.2 no.4
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• pp.490-508
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• 1998

One of the latest fields of research in the area of output devices is tactual display devices [13,31]. These tactual or haptic devices allow the user to receive haptic feedback output from a variety of sources. This allows the user to actually feel virtual objects and manipulate them by touch. This is an emerging technology and will be instrumental in enhancing the realism of wearable augmented environments for certain applications. Tactual displays have previously been used for scientific visualization in virtual environments by chemists and engineers to improve perception and understanding of force fields and of world models populated with the impenetrable. In addition to tactual displays, the use of wearable audio displays that allow sound to be spatialized are being developed. With wearable computers, designers will soon be able to pair spatialized sound to virtual representations of objects when appropriate to make the wearable computer experience even more realistic to the user. Furthermore, as the number and complexity of wearable computing applications continues to grow, there will be increasing needs for systems that are faster, lighter, and have higher resolution displays. Better networking technology will also need to be developed to allow all users of wearable computers to have high bandwidth connections for real time information gathering and collaboration. In addition to the technology advances that make users need to wear computers in everyday life, there is also the desire to have users want to wear their computers. In order to do this, wearable computing needs to be unobtrusive and socially acceptable. By making wearables smaller and lighter, or actually embedding them in clothing, users can conceal them easily and wear them comfortably. The military is currently working on the development of the Personal Information Carrier (PIC) or digital dog tag. The PIC is a small electronic storage device containing medical information about the wearer. While old military dog tags contained only 5 lines of information, the digital tags may contain volumes of multi-media information including medical history, X-rays, and cardiograms. Using hand held devices in the field, medics would be able to call this information up in real time for better treatment. A fully functional transmittable device is still years off, but this technology once developed in the military, could be adapted tp civilian users and provide ant information, medical or otherwise, in a portable, not obstructive, and fashionable way. Another future device that could increase safety and well being of its users is the nose on-a-chip developed by the Oak Ridge National Lab in Tennessee. This tiny digital silicon chip about the size of a dime, is capable of 'smelling' natural gas leaks in stoves, heaters, and other appliances. It can also detect dangerous levels of carbon monoxide. This device can also be configured to notify the fire department when a leak is detected. This nose chip should be commercially available within 2 years, and is inexpensive, requires low power, and is very sensitive. Along with gas detection capabilities, this device may someday also be configured to detect smoke and other harmful gases. By embedding this chip into workers uniforms, name tags, etc., this could be a lifesaving computational accessory. In addition to the future safety technology soon to be available as accessories are devices that are for entertainment and security. The LCI computer group is developing a Smartpen, that electronically verifies a user's signature. With the increase in credit card use and the rise in forgeries, is the need for commercial industries to constantly verify signatures. This Smartpen writes like a normal pen but uses sensors to detect the motion of the pen as the user signs their name to authenticate the signature. This computational accessory should be available in 1999, and would bring increased peace of mind to consumers and vendors alike. In the entertainment domain, Panasonic is creating the first portable hand-held DVD player. This device weight less than 3 pounds and has a screen about 6' across. The color LCD has the same 16:9 aspect ratio of a cinema screen and supports a high resolution of 280,000 pixels and stereo sound. The player can play standard DVD movies and has a hour battery life for mobile use. To summarize, in this paper we presented concepts related to the design and use of wearable computers with extensions to smart spaces. For some time, researchers in telerobotics have used computer graphics to enhance remote scenes. Recent advances in augmented reality displays make it possible to enhance the user's local environment with 'information'. As shown in this paper, there are many application areas for this technology such as medicine, manufacturing, training, and recreation. Wearable computers allow a much closer association of information with the user. By embedding sensors in the wearable to allow it to see what the user sees, hear what the user hears, sense the user's physical state, and analyze what the user is typing, an intelligent agent may be able to analyze what the user is doing and try to predict the resources he will need next or in the near future. Using this information, the agent may download files, reserve communications bandwidth, post reminders, or automatically send updates to colleagues to help facilitate the user's daily interactions. This intelligent wearable computer would be able to act as a personal assistant, who is always around, knows the user's personal preferences and tastes, and tries to streamline interactions with the rest of the world.

• Tuberculosis and Respiratory Diseases
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• v.63 no.6
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• pp.497-506
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• 2007

Background: The present investigation was performed in rats and isolated human neutrophils in order to confirm the presumptive role of the positive feedback loop of cytosolic phospholipase $A_2$ ($cPLA_2$) activation by plateletactivating factor (PAF). Methods: The possible formation of the positive feedback loop of the $cPLA_2$ activation and neutrophilic respiratory burst was investigated in vivo and in vitro by measurement of the parameters denoting acute lung injury. In addition, morphological examinations and electron microscopic cytochemistry were performed for the detection of free radicals in the lung. Results: Five hours after intratracheal instillation of PAF ($5{\mu}g/rat$), the lung leak index, lung myeloperoxidase (MPO) activity, the number of neutrophils and the concentration of cytokine-induced neutrophil chemoattractant (CINC) in bronchoalveolar lavage fluid were increased by PAF as compared with those of control rats. The NBT assay and cytochrome-c reduction assay revealed an increased neutrophilic respiratory burst in isolated human neutrophils following exposure to PAF. Lung and neutrophilic $cPLA_2$ activity were increased following PAF exposure and exposure to hydrogen peroxide increased $cPLA_2$ activity in the lung. Histologically, inflammatory findings of the lung were observed after PAF treatment. Remarkably, as determined by $CeCl_3$ cytochemical electron microscopy, increased production of hydrogen peroxide was identified in the lung after PAF treatment. Conclusion: PAF mediates acute oxidative lung injury by the activation of $cPLA_2$, which may provoke the generation of free radicals in neutrophils.