This investigation aimed to assess the appetite response changes of olive flounder to starving and re-feeding conditions. Three different feeding groups (2 weeks feeding, fed; 2 weeks starving, starved; and 1 week starving and 1 week feeding, re-fed) were established to examine the changes in appetite-related genes for each group. The weight gain of the fish was highest for the fed group and lowest for the starving group. Based on the daily feed intake (DFI) and cumulative feed intake (CFI), overall food intake was found to increase in the re-fed group more than in the fed group from week 1 to week 2 of the experiment. Hypocretin neuropeptide precursor (HCRT) and galanin receptor 1 (GAL-R1) mRNA expression in the brain of olive flounder were decreased in the starved group. Corticotropin-releasing hormone (CRH) was decreased in all experimental groups, except for the fed group. However, overall leptin concentrations in the plasma did not change across groups. Considering the differences between this study and previous studies on starving and feeding, various factors (except the production and expression mechanisms of appetite-related factors in response to starving) are likely acting on the appetite responses of the fish. In this study, a 1-week re-feeding period induced substantial effects on appetite response when compared to a 2-week feeding period. These findings show that even if re-feeding is performed after starving, the unbalance caused by the re-feeding can affect various physiological changes in fish by feed intake efficiency.

Once a radioactive material is released from the nuclear power plant (NPP) by accident, it is necessary to understand the behavior of radioactive plume to protect residents adequately. For this, it is essential to measure the radiation dose rate around NPPs at important locations. Our previous study developed a movable radiation detector that can be installed quickly in an accident to measure gamma dose rate in areas where environmental radiation monitoring system is not installed. The data measured by the detector are transmitted to the server in real-time through LoRA wireless communications. There are two methods to use LoRA communications; one is self-network, and the other is the network provided by the mobile carrier. A signal receiver, called a gateway, should be equipped near the installation location of radiation detectors to use a self-network without using the mobile carrier’s system. In other words, the movable radiation detectors we made can function if there should be any gateway near them. The distance capable of communication between gateway and detector is about 8 km in an open area without significant obstacles. Korea has many significant obstacles, such as mountains around most NPPs. Thus, the gateways could be installed in the proper position before the accident to operate the movable radiation detectors without problems. If the gateway is located at a high position like a mountain top, it could cover a wide area. In this study, the elevation database in the area around the NPPs was collected and analyzed to determine where gateways should be installed. The analysis range is limited in the urgent protective action planning zone. The optimization was also performed to minimize the number of gateways.

The Kori Unit 1 and Wolsong Units 1, commercial reactors in South Korea, were permanently shut down due to the expiration of their design lifetime. Therefore, nuclear power plants that have been permanently shut down must be dismantled, and the site must be finally released after removing the remaining radionuclides. Domestic regulatory standards for site remediation should not exceed 0.1 mSv per year based on effective dose. In addition, it is necessary to calculate the preliminary Derived Concentration Guideline Levels (DCGL) to prove that the conditions are met. Therefore, in this study, the input factor considering the geological characteristics of the site of Kori Unit 1 was investigated, and the preliminary Derived Concentration Guideline Levels were calculated and compared with the results of previous studies. As a result of comparative analysis, 60Co, 134Cs, and 137Cs, which are gamma-ray emitting radionuclides, had similar values to DCGL of previous studies A and B. However, 63Ni, a beta-rayemitting nuclide, was 5.94×104 Bq·g−1 in this study and 8.47×101 Bq·g−1in previous study B, resulting in a difference of about 700 times. In addition, in the case of 90Sr, this study and previous study A were derived similarly, but this study was 5.34×101 Bq·g−1 and previous study B was 1.18×10−1 Bq·g−1, resulting in a difference of about 450 times. This difference is judged to be because, unlike this study using only the industrial worker scenario, in the case of previous study B, the resident farmer scenario was mixed and used, which considers the internal exposure caused by ingestion of food produced in the contaminated area. In this study, it was confirmed that DCGL according to the change of geological factors of the site did not have a significant effect on gamma-ray-emitting nuclides. However, it was confirmed that considering the intake of food affects the DCGL of beta-ray-emitting nuclides. Therefore, there is a need to conduct future studies applying intake input factors that meet domestic conditions.

This study deals with replacement analysis of deteriorated equipment for improving productivity of production system. Frequent breakdown of the deteriorated equipment causes a situation that reduces productivity such as low product quality, process delay, and repair cost. However, the replacement of new equipment will be required a high initial investment cost, so it is important to analysis the economic feasibility. Therefore, we analyze the effect of the production system due to the aging effect of the equipment and the feasibility of equipment replacement based on the economic analysis. The process flow, working time, logistics movement, etc. are analyzed in order to build the simulation modeling for a ship and land switchboard production system. Using numerical examples, the economic feasibility analysis of equipment replacement through replacement of existing deteriorated equipment and additional arrangement of new facilities is performed.

The PoN (Proof of Nonce) distributed consensus algorithm basically uses a non-competitive consensus method that can guarantee an equal opportunity for all nodes to participate in the block generation process, and this method was expected to resolve the first trilemma of the blockchain, called the decentralization problem. However, the decentralization performance of the PoN distributed consensus algorithm can be greatly affected by the network transaction transmission delay characteristics of the nodes composing the block chain system. In particular, in the consensus process, differences in network node performance may significantly affect the composition of the congress and committee on a first-come, first-served basis. Therefore, in this paper, we presented a problem by analyzing the decentralization performance of the PoN distributed consensus algorithm, and suggested a fairness control algorithm using a learning-based probabilistic acceptance rule to improve it. In addition, we verified the superiority of the proposed algorithm by conducting a numerical experiment, while considering the block chain systems composed of various heterogeneous characteristic systems with different network transmission delay.

In order to extend the business viability of carbon nanotubes (CNTs), research on CNT dispersion in a solvent as well as in polymer matrix should be established. Herein, three kinds of dispersing agents, sodium deoxycholate (DOC), sodium dodecylbenzene sulfonate (NaDDBS), polyvinyl pyrrolidone (PVP), are selected and applied to quantify the dispersibility and dispersion stability of CNT aqueous dispersion. The dispersibility of CNT dispersion with the PVP, evaluated via viscosity and particle size analyses, are superior to those with the DOC and NaDDBS dispersing agents. CNT aqueous solution dispersed with PVP showed slightly higher viscosity and narrower particle size distribution than those with DOC and NaDDBS dispersing agents. In addition, the dispersion stability of CNT dispersion with the PVP, measured via lumisizer analyses, are superior to those with the DOC and NaDDBS dispersing agents. HR-TEM analysis verifies that the outstanding dispersibility and dispersion stability of CNTs in aqueous solution are due to the effect of the robust polymer wrapping of the PVP dispersing agent on the CNT surface. From the results of this study, the guidelines for the selection of the suitable dispersing agents and the systematic evaluation of dispersibility and dispersion stability of CNT dispersions can be suggested.

The purpose of this study was to investigate the effects of extract mixture of C. wilfordii and P. umbrosa (IPLUS-CWPU) on bone growth in 4-week old young male SD rats. To confirm the effect of IPLUS-CWPU, we measured the length of bone growth plate, the ratio of proliferative zone to the length of growth plate and the expression level of insulin-like growth factor, IGF-1. The IPLUS-CWPU treatment shows a significant increase of tibial and femoral growth plate and the ratio of proliferative zone in growth plate. Especially, the length increased by 13.9% and 25.3% in the tibia and femur, respectively, in the high-dose group compared to the normal group. Moreover, the expression of IGF-1 gene in liver was upregulated in IPLUS-CWPU treated groups. These results indicated that IPLUS-CWPU administration could increase the proliferative zone of bone growth plate in early developmental stage by upregulation of IGF-1 gene.