• Imaging Science in Dentistry
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• v.42 no.4
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• pp.237-242
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• 2012

Purpose: The objectives of this study were to survey the radiographic exposure parameters, to measure the patient doses for intraoral dental radiography nationwide, and thus to establish the diagnostic reference levels (DRLs) in intraoral dental X-ray examination in Korea. Materials and Methods: One hundred two intraoral dental radiographic machines from all regions of South Korea were selected for this study. Radiographic exposure parameters, size of hospital, type of image receptor system, installation duration of machine, and type of dental X-ray machine were documented. Patient entrance doses (PED) and dose-area products (DAP) were measured three times at the end of the exit cone of the X-ray unit with a DAP meter (DIAMENTOR M4-KDK, PTW, Freiburg, Germany) for adult mandibular molar intraoral dental radiography, and corrections were made for room temperature and pressure. Measured PED and DAP were averaged and compared according to the size of hospital, type of image receptor system, installation duration, and type of dental X-ray machine. Results: The mean exposure parameters were 62.6 kVp, 7.9 mA, and 0.5 second for adult mandibular molar intraoral dental radiography. The mean patient dose was 2.11 mGy (PED) and 59.4 $mGycm^2$ (DAP) and the third quartile one 3.07 mGy (PED) and 87.4 $mGycm^2$ (DAP). Doses at university dental hospitals were lower than those at dental clinics (p<0.05). Doses of digital radiography (DR) type were lower than those of film-based type (p<0.05). Conclusion: We recommend 3.1 mGy (PED), 87.4 $mGycm^2$ (DAP) as the DRLs in adult mandibular molar intraoral dental radiography in Korea.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2000.06a
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• pp.1-10
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• 2000

The development of paper machines, increasing machine speeds with new, mostly low basis weight and/or high ash content paper grades, as well as the fact that several trends regarding process items have increased the sensitivity of papermaking. At the same time, papermakers are looking for flexibility in the production line. We can say that with all PMs the biggest benefits with the lowest capital spending can be achieved by focusing on improved wet end management. In order to manage wet end chemistry on a paper machine, our goal is to control sub-process through which we can influence the operation of the entire wet end with maximum effect. Key measurements and controls are-white water consistency control which is the most effective way to control retention - charge demand measurement and control which takes care of concentration of the anionic material entering to PM -ash measurements and controls which are deeply related to retention and paper quality This paper presents and concentrates to two of these key controls ; retention and charge. The purpose of charge control is to give the process control the tools to react to changes caused by amount of dissolved and colloida material incoming to wet end system. It is called coagulation or fixing control. Retention control is then taking care of retention aid flow to the process by responding any changes seen in white water consistency. It is called flocculation control. Each of these solutions separately , and even more effectively all together, stabilize the wet end operations and so greatly improve the produced paper quality and machine runnability. Practical results will be presented and they are referring to the latest mill cases. We have developed the first wet end measuring system in the late 1980s and control solutions based on this modern measuring technology were completely updated in 1990s. This paper introduces the principle, operation , and results of our unique wet end analyzers (retention and charge ) which are at the level of automation solutions as a part of paper machine quality control Especially our newest member of the platform , on-line charge analyzer has reached and set new standards to the on-line charge monitoring.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.3
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• pp.478-484
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• 2008

When a mobile node moves, MIPv6 operates an authentication process for the new connection. These kinds of frequent binding update and authentication processes cause much traffic and delay the service. To solve this problem, PMIPv6 provides a network-based mobility protocol in order to lessen the load on a mobile node. However, when it is moved from a domain to a domain or in a domain, there still lies a need fDr a new address, so MIPv6's demerit still exists. In IPsec, too, a new negotiation should be made when it is moved to WAN(Wide Area Network). This causes load to the mobile node. In this paper suggests MBB(Make Before Break) system to eliminate disconnections or delays resulted from the address change or renegotiation for security. When the mobile node receives a CoA address, IPsec negotiation gets operated. Its identity is authenticated by sending the identifier used for the prior negotiation to CN(Correspondent Node) through the BID message suggested. After that, negotiation Bets simplified that disconnections can be eliminated, and in the IPsec negotiation, the load on the mobile node can be lessened as well; moreover, two addresses are used for the communication simultaneously, so the probability of packet loss can be reduced.

• Development and Reproduction
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• v.23 no.2
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• pp.93-99
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• 2019

Nonylphenols (NPs) are widely used industrial materials, and are considered as potent endocrine disrupting chemical. Present study was undertaken to clarify the effect of subchronic low-dose NP exposure to F1 generation male mice. Mice were divided into 2 groups; (1) CON, control animals and (2) NP-50 ($50{\mu}g/L$), animals were treated with NP via drinking water. NP exposures were continuously conducted from parental pre-mating period until the postnatal day (PND) 55 of F1 offsprings. Mice were sacrificed on PND 55 and the tissue weights were measured. The initial body weights (at PND 21) and terminal body weights (PND 55) of the NP-50 animals were significantly lower than those of control animals (p<0.05). NP exposure induced a significant increase in the absolute weight of the testes (p<0.05). Conversely, the NP exposure caused significant decrease in the absolute weights of the epididymis (p<0.01), prostate (p<0.05) and seminal vesicle (p<0.05). Histopathological studies revealed that NP-treated animals exerted decreased seminiferous tubule diameters, reduced luminal area, and lower number of germ cells. Also some sloughing morphologies in the tubules were observed. In the caudal epididymis, fewer mature sperms and swollen epithelial cells were found in the NP-treated group. Our results confirmed that the subchronic low-dose NP exposure altered some male parameters and induced histopathological abnormalities in testis and epididymis of F1 mice. Since the NP dose used in this study is close to the average human daily NP exposure, our results could provide practically meaningful understanding of adverse effect of EDC in human.

• Journal of Dental Anesthesia and Pain Medicine
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• v.19 no.1
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• pp.45-54
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• 2019

Background: Profound anesthesia with adequate duration is required in periodontal flap surgery, which involves the manipulation of both hard and soft tissues. The anterior middle superior alveolar (AMSA) injection may be an alternative to multiple injections required for this purpose in the maxilla. The present study aimed to assess the effectiveness of AMSA injection using computer-controlled local anesthetic delivery (CCLAD) system to anesthetize buccal hard tissue (BHT), buccal soft tissue (BST), palatal hard tissue (PHT), and palatal soft tissue (PST) around the maxillary teeth. Methods: Thirty-five patients who were indicated for open flap debridement in a whole maxillary quadrant were given AMSA injection using the CCLAD. The effectiveness of anesthesia was evaluated using subjective and objective parameters around each tooth. Supraperiosteal infiltrations were administered to complete the surgery wherever the AMSA injection was ineffective. Results: The AMSA injection was more effective on the palatal tissues than on the buccal tissues, as 94.14% of PST and 87.89% of PHT sites were anesthetized compared to 49.22% and 43.75% of BHT and BST sites, respectively. There was no significant difference in the frequency of anesthesia around the anterior and posterior teeth. The PHT was significantly more anesthetized (P = 0.003) in males than in females. Conclusions: The AMSA injection using CCLAD is highly effective on palatal tissues and could be used as a first-line anesthesia for periodontal flap surgery. However, its effect on buccal tissues is less predictable, with supraperiosteal infiltration often required to supplement the AMSA injection.

• Journal of radiological science and technology
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• v.42 no.1
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• pp.25-30
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• 2019

Whole Spine Scanography (WSS) using the Digital Radiography (DR) system is an examination that requires whole body X-ray exposure, which involves more exposure to radiation for patients than other general radiographies. This can affect the occurrence of breast cancer. This research measured radiation dose when breasts were shield and not shield using the Auto Exposure Control (AEC) mode. The radiation dose without a shield was 1.540 mGy, and that using a collimator was measured 0.506 mGy. Moreover, 0.733 mGy was measured when 1 shield (0.3 mm) was used, and $0.523{\mu}Gy$ when 5 of them (1.5 mm) were used. The results showed that the radiation dose with 5 shields and the radiation dose with a collimator were similar. Moreover, 0.233 mGy was measured when 8 shields (2.4 mm) were used. The standard deviation were 0.081 when using collimator and 0.014 when 5 shields were used. Also, when 8 shields were used, it was found to be 0.002. Most patients who go under a scoliosis test are children or young people who are highly sensitive to radiation. In the research results, the case where the organs sensitive to radiation, women's breasts, were shielded showed more distinct differences compared to without shields. It is considered that using shields can provide more constant shield than using a collimator and lower the risk of breast cancer caused by exposure to radiation.

• Development and Reproduction
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• v.23 no.3
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• pp.255-262
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• 2019

Previously, we reported negative effects of low-dose nonylphenol (NP) exposure on the reproductive organs of F1 male mice. In the present study was further investigated the endocrine disrupting effect of NP exposure to F2 generation male mice. Mice were divided into 2 groups; (1) CON, control animals and (2) NP-50 ($50{\mu}g/L$), animals were treated with NP via drinking water. NP exposures were continuously conducted from parental pre-mating period until the postnatal day (PND) 55 of F2 offsprings. Mice were sacrificed on PND 55 and the reproductive tissue weights were measured. The initial (at PND 21) and terminal (PND 55) body weights of the NP-50 group animals were not significantly different from those of control group animals. NP exposure fail to induce a significant weight change of the testes, seminal vesicle and prostate except absolute epididymal weight (p<0.05). However, pathohistological studies revealed that NP-treated F2 animals showed evident decrease in seminiferous tubule diameters, reduced luminal area and number of germ cells. Also, sloughing morphologies in the tubules were notable. In the caudal epididymis, fewer mature sperms and swollen epithelial cells were found in the NP-treated group. The present study demonstrated that the subchronic low-dose NP exposure induced pathohistological abnormalities in testis and epididymis of F2 mice, and we assumed that these 'qualitative' changes in reproductive tissues could be derived from the epigenetic modifications such as DNA methylation, histone modification, altered DNA accessibility and chromatin structure. Further studies are needed to achieve a better understanding on the multi- or trans-generational effects of NP on the reproductive health and a human application.

• Environmental and Resource Economics Review
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• v.30 no.1
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• pp.107-128
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• 2021

It has been recognized that implementing the marginal price mechanism to CBP is not acceptable due to the lack of revenue of the marginal generators. This study shows that it is not the problem of marginal price mechanism but the structural problems originated by the suspension of restructuring, the technical limits of RSC program and inaccuracy of the generation cost estimation method. This study explains the method to calculate the cost function in operating modes of the CC generators and proposes the modeling for the CC generators in RSC program. To implementing the cost function in operating modes could give an opportunity to change the price setting mechanism from average to marginal cost. The price setting mechanism based on the marginal cost will be one of the main points to provide the right price signals and to introduce a real-time and A/S markets to prepare the energy transition era.

• Journal of radiological science and technology
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• v.45 no.5
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• pp.397-405
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• 2022

Computed radiography (CR) systems, which convert an analog signal recorded on a cassette into a digital image, combine the characteristics of analog and digital imaging systems. Compared to digital radiography (DR) systems, CR systems have presented difficulties in evaluating system performance because of their lower detective quantum efficiency, their lower signal-to-noise ratio (SNR), and lower modulation transfer function (MTF). During the step of energy-storing and reading out, a baseline offset occurs in the edge area and makes low-frequency overestimation. The low-frequency offset component in the line spread function (LSF) critically affects the MTF and other image-analysis or qualification processes. In this study, we developed the method of baseline correction using mathematical morphology to determine the LSF and MTF of CR systems accurately. We presented a baseline correction that used a morphological filter to effectively remove the low-frequency offset from the LSF. We also tried an MTF evaluation of the CR system to demonstrate the effectiveness of the baseline correction. The MTF with a 3-pixel structuring element (SE) fluctuated since it overestimated the low-frequency component. This overestimation led the algorithm to over-compensate in the low-frequency region so that high-frequency components appeared relatively strong. The MTFs with between 11- and 15-pixel SEs showed little variation. Compared to spatial or frequency filtering that eliminated baseline effects in the edge spread function, our algorithm performed better at precisely locating the edge position and the averaged LSF was narrower.

• Development and Reproduction
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• v.27 no.4
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• pp.205-211
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• 2023

INTS14/VWA9, a component of the integrator complex subunits, plays a pivotal role in regulating the fate of numerous nascent RNAs transcribed by RNA polymerase II, particularly in the biogenesis of small nuclear RNAs and enhancer RNAs. Despite its significance, a comprehensive mutation model for developmental research has been lacking. To address this gap, we aimed to investigate the expression patterns of INTS14 during zebrafish embryonic development. We generated ints14 mutant strains using the CRISPR/Cas9 system. We validated the gRNA activity by co-injecting Cas9 protein and a single guide RNA into fertilized zebrafish eggs, subsequently confirming the presence of a 6- or 9-bp deletion in the ints14 gene. In addition, we examined the two mutant alleles through PCR analysis, T7E1 assay, TA-cloning, and sequencing. For the first time, we used the CRISPR/Cas9 system to create a model in which some sequences of the ints14 gene were removed. This breakthrough opens new avenues for in-depth exploration of the role of ints14 in animal diseases. The mutant strains generated in this study can provide a valuable resource for further investigations into the specific consequences of ints14 gene deletion during zebrafish development. This research establishes a foundation for future studies exploring the molecular mechanisms underlying the functions of ints14, its interactions with other genes or proteins, and its broader implications for biological processes.