• Environmental Analysis Health and Toxicology
• /
• 제22권1호
• /
• pp.1-8
• /
• 2007

Biological monitoring, analyses of internal dose for exposure to toxicants, has been thought as one of the belt approaches for risk assessment. As the amount detected in human samples is generally very low, typically in the parts-per-bilion (ppb) or parts-per-trillion (ppt) range, analytic technologies such at HPLC, GC/MS, LC/MS, and LC/MS/MS have been continuously developed. In addition, route specific and sensitive exposure biomarkers have been developed for proper biological monitoring. PBPK modeling, particularly reverse dosimetry, has been emphasized as an useful method via interpretation of biological monitoring results for regulation of toxicants. Thus, this review is focused on the use of PBPK dosimetry models for toxicology research and risk assessment in Korea.

• 유통과학연구
• /
• 제22권4호
• /
• pp.59-68
• /
• 2024

Purpose: The function of internal audit is to help achieve company goals and targets by minimizing the impact of business risks. The distribution of internal audit activities in carrying out control and supervision covers all aspects or activities at all levels of management. The aim of the research is to determine the distribution of risk-based internal audit effectiveness assessments in companies. Data and Research Design Methodology: Researchers examined research trends regarding things that could influence the distribution of the effectiveness of the internal audit function from 2007 to 2023.This research used a systematic literature review (SLR) research method. This research used 23 papers sourced from the Scopus database. Results: The distribution of the effectiveness of audit services provided by internal auditors is more influenced by the personal characteristics of internal auditors and has little to do with the leadership of the chief internal auditor, technology, and risk management. Conclusion: The distribution of monitoring services provided by internal auditors covers all levels of departments or divisions of the organization. The assessment of internal audit effectiveness is more influenced by the auditor's personal attributes such as independence, competence, and management support.

• 한국복합재료학회:학술대회논문집
• /
• 한국복합재료학회 2005년도 춘계학술발표대회 논문집
• /
• pp.17-20
• /
• 2005

In-situ structural health monitoring of filament wound pressure tanks were conducted during water-pressurizing test using embedded fiber Bragg grating (FBG) sensors. We need to monitor inner strains during working in order to verify the health condition of pressure tanks more accurately because finite element analyses on filament wound pressure tanks usually show large differences between inner and outer strains. Fiber optic sensors, especially FBG sensors can be easily embedded into the composite structures contrary to conventional electric strain gages (ESGs). In addition, many FBG sensors can be multiplexed in single optical fiber using wavelength division multiplexing (WDM) techniques. We fabricated a standard testing and evaluation bottle (STEB) with embedded FBG sensors and performed a water-pressurizing test. In order to increase the survivability of embedded FBG sensors, we suggested a revised fabrication process for embedding FBG sensors into a filament wound pressure tank, which includes a new protecting technique of sensor heads, the grating parts. From the experimental results, it was demonstrated that FBG sensors can be successfully adapted to filament wound pressure tanks for their structural health monitoring by embedding.

• Corrosion Science and Technology
• /
• 제4권5호
• /
• pp.178-190
• /
• 2005

In order to develop a new corrosion sensor for detecting and monitoring the external and internal corrosion damage of buried pipeline, the electrochemical property of sensors and the correlation of its output to corrosion rate of steel pipe, were evaluated by electrochemical methods in two soils of varying resistivity (5,000 ohm-cm, 10,000 ohm-cm) and synthetic tap water environments. In this paper, two types of galvanic probes were manufactured: copper-pipeline steel (Cu-CS) and stainless steel-pipeline steel (SS-CS). The corrosion behavior in synthetic groundwater and synthetic tap water for the different electrodes was investigated by potentiodynamic test. The comparison of the sensor output and corrosion rates revealed that a linear relationship was found between the probe current and the corrosion rates. In the soil resistivity of $5,000{\Omega}-cm$ and tap water environments, only the Cu-CS probe had a good linear quantitative relationship between the sensor output current and the corrosion rate of pipeline steel. In the case of $10,000{\Omega}-cm$, although the SS-CS probe showed a better linear correlation than that of Cu-CS probe, the Cu-CS probe is more suitable than SS-CS probe due to the high current output.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
• /
• pp.739-744
• /
• 2000

Concrete structures generally have cracks, so for the safety and durability of structures, studies to detect cracks using nondestructive tests have been treated in great deal. In order to assure the reliability of concrete structure, microscopic fracture behavior and internal damage progress of concrete under the loading should be fully understood. The purpose of this study predicts location of initial crack and measures direction of crack propagation for on-line monitoring before the crack really grows in structures by using two-dimensional Acoustic Emission(AE) source location based on rectangular method with three-point bending test. This will allow efficient maintenance of concrete structure through monitoring of internal cracking based on AE method.

• 대한한방내과학회지
• /
• 제19권1호
• /
• pp.291-300
• /
• 1998

Dementia is the neurodegenerative process that affects cognition, behavior and function and one of the most prominent diseases of dementia is Alzheimer's disease(AD). AD is a dementing illness characterized clinically by the progressive and irreversible deafferentation of the limbic system, association neocortex and basal forebrain. A number of conditions are known to be predisposing risk factors for AD. In several of these, initiation of glial-mediated inflammatory pathways as a mechanism of AD is getting a lot of attention. On the other hand, a biochemical marker for monitoring the onset and progression of the disease would be a valuable tool for disease management. Also such a marker might be used as an end point in clinical intervention protocols. This biochemical marker will have the potential for identifying subjects afflicted with the disease and possibly for monitoring the onset and longitudinal progression of the disease. Here we have reviewed the latest papers of different approaches to AD. Of course, there is a section of PET which is very useful clinically nowadays.

• International Journal of Reliability and Applications
• /
• 제11권2호
• /
• pp.69-87
• /
• 2010

The optimal replacement problem was investigated for a multi-state deteriorated system for which the true internal state cannot be observed directly except when the system breaks down completely. The internal state was assumed to be monitored incompletely by a monitor that gives information related to the true state of the system. The problem was formulated as a partially observable Markov decision process. The optimal procedure was found to be a monotone procedure with respect to stochastic increasing ordering of the state probability vectors under some assumptions. Limiting the optimal procedure to a monotone procedure would greatly reduce the tremendous amount of calculation time required to find the optimal procedure.

• Industrial Engineering and Management Systems
• /
• 제7권1호
• /
• pp.23-33
• /
• 2008

This paper proposes an approach to monitoring and scheduling methods for repetitive MIMO-FIFO DESs. We use max-plus algebra for modeling and formulation, known as an effective approach for controller design for this type of system. Because a certain type of linear equations in max-plus algebra can represent the system's behavior, the principal concerns in past researches were how to solve the equations. However, the researches focused mainly on analyses of the relation between inputs and outputs of the system, which implies that the changes or the slacks of internal states were not clarified well. We first examine several properties of the corresponding state variables, which contribute to finding and tracing the float times in each process. Moreover, we provide a rescheduling method that can take into account delays or changes of the internal states. These methods would be useful in schedule control or progress management.

• 한국환경보건학회지
• /
• 제35권2호
• /
• pp.100-115
• /
• 2009

Secondhand smoke (SHS) is one of major public health threats. Since secondhand smoke is complex mixture of toxic chemicals, there has been no standardized method to measure SHS quantitatively. The purpose of this manuscript was to review various quantitative methods to measure SHS. There are two different methods: air monitoring and biological monitoring. Air monitoring methods include exhaled carbon monoxide level, ambient fine particulates, nicotine and 3-ethenylpyridine. Measurement of fine particulates has been utilized due to presence of real-time monitor, while fine particulates can have multiple indoor sources other than SHS. Ambient nicotine and 3-EP are more specific to SHS, although there is no real-time monitor for these chemicals. Biological monitoring methods include nicotine in hair, cotinine in urine, NNK in urine and DNA adducts. Nicotine in hair can provide chronic internal dose, while cotinine in urine can provide acute dose. Since biological monitoring can provide total internal dose, identification of specific exposure source may be difficult. NNK in urine can indicate carcinogenicity of the SHS exposure. DNA adducts can provide overall cancer causing exposure, but not specific to SHS. While there are many quantitative methods to measure SHS, selection of appropriate method should be based on purposes of assessment. Application of accurate and appropriate exposure assessment method is important for understanding health effects and establishing appropriate control measures.

• 대한한방내과학회지
• /
• 제21권4호
• /
• pp.687-691
• /
• 2000

In this case report regarding one patient with complete left bundle branch block and mild hypokinesia of left ventricle, who had cebebellar infarction and therefore showed the symptoms of cerabellar dyskinesia followed by dyspnea, chest discomfortness, insomnia and dry cough. From the point of oriental diagnostic criteria, the patient s clinical conditions were all classified as $^{\circ}AEdeprivation$ of kidney essence' and treated accordingly. He showed no change in EKG monitoring but above symptoms were removed markedly after following treatment. Further elaboration of oriental diagnostic classification could possibly lead to the fundamental treatment.