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.

Globally, colon cancer is increased gradually and known as one of the major causes of cancer death. Stevia, a substitute of sugar, is known to have many components including alpha-tocopherol and anthocyanin etc, as antioxidants. This study's purpose is to investigate whether stevia plant extract can have a protective effect against colon carcinogenesis induced by azoxymethane (AOM) and dextran sodium sulfate (DSS) in mice. Total 30 male ICR mice were divided into 2 groups; AOM/DSS treatment (control group), AOM/DSS + stevia extract (0.5%, in drinking water). After acclimation for 1 week, five weeks old mice received three intraperitoneal AOM (10 mg/kg b.w.) injections weekly for 3 weeks (0–2nd weeks of the experiment) and 2% DSS as drinking water for the next one week. AIN-76A purified rodent diet and 0.5% stevia extract water were supplied to the animals for 6 weeks. The colons of mice were collected and the number of aberrant crypt foci (ACF) and aberrant crypts (ACs) in colonic mucosa were counted after staining with methylene blue. Malondialdehyde (MDA) concentration in feces were determined. The numbers of ACF and ACs were significantly (p<0.01) decreased in stevia-treated group compared with the control group. The MDA concentration in feces was also significantly (p<0.01) decreased in stevia-treated group compared with the control group. In histopathology of colonic epithelium, hyperplasia of colonic epithelium was less observed in steviatreated group. These results indicate that stevia has a protective effect against colon carcinogenesis induced by AOM/DSS in mice and further study needs to illustrate the protective mechanisms.

메주와 누룩은 한국 전통 발효 식품에 사용되는 스타터로, Aspergillus속 곰팡이나 aflatoxin에 노출되기 쉽다. 본 연구에서는 우리나라에서 시판되는 57개의 메주 시료와 18개의 누룩 시료로부터 Aspergillus 속 곰팡이를 분리하고 동정하였다. 분리주의 aflatoxin 생성 가능성을 평가하기 위하여 multiplex PCR을 통해 aflatoxin 생합성 유전자 (aflO, aflP, aflR)를 확인하고, 이들 분리주에 의해 생성되는 aflatoxin 함량을 HPLC로 조사하였다. 뿐만 아니라 시판 메주와 누룩 시료 중 aflatoxin 함량을 분석하였다. 그 결과, 메주 시료로부터 130개, 누룩 시료로부터 47개 균주가 분리되어 총 177개의 분리주를 확인 및 동정하였다. 각 각 메주와 누룩으로부터 분리된 19.2% (25/130), 10.6% (5/ 47)의 분리주가 3 종류의 aflatoxin 생합성 유전자를 모두 보유하였으며, 그 중 메주로부터 분리된 5개의 분리주가 실제 로 aflatoxin을 생성하였다. 시판 메주와 누룩 시료 중 aflatoxin 함량을 분석한 결과, 88% (51/58)의 메주 시료의 aflatoxin 오염 수준은 모두 검출한계 미만으로 나타났고, 누룩 또한 시료의 39% (7/18)가 검출한계 미만으로 확인되었다. 메주와 누룩에서 분리된 분리주 중 aflatoxin 생합성 유전자를 모두 보유하거나 배지 상에서 aflatoxin 생성을 보여준 aflatoxigenic 균주는 존재하였으나 유통되고 있는 시료에서 aflatoxin 오염 빈도는 낮은 수준임을 확인할 수 있었다.

뽕나무깍지벌레는 복숭아, 매실, 뽕나무 등 31종의 기주식물을 가해하는 기주범위가 광범위한 난방제 해충으로 알려져 있다. 2017년도에 뽕나무깍지벌레는 5월 상순부터 부화를 시작하여 암컷성충 1마리가 75.5개(47~159개)의 알을 낳으며 모든 알이 부화하는데 약 19일이 소요되었고, 부화율은 약 87%였다. 반면에 2018년도에는 4월 하순부터 부화를 시작하여 암컷성충 1마리가 49.4개(12~71개)의 알을 낳으며 모든 알이 부화하는데 13일이 소요되었으며, 부화율은 약 72%를 보였다. 부화한 약충들은 이동 후 5월 중순부터 고착약충으로 되고, 6월 중순부터 2세대 성충이 활동하기 시작하였다. 부화약충기에 약제를 살포하여 살충효과를 조사한 결과, 살충률이 100%인 반면에, 고착약충기 에는 살충율은 2.7%로 살충효과가 낮은 것을 확인하였다.

The microstructure, flexural properties, electrical conductivity, thermal conductivity and electromagnetic interference (EMI) shielding effectiveness (SE) of epoxy composites filled with multi-walled carbon nanotubes (CNTs), exfoliated graphite nanoplatelets (xGnPs) and CNT-xGnP hybrid filler were investigated. The EMI SE of the CNT-xGnP hybrid composite was higher than 25 dB at 100 MHz while that of the xGnP based composite was almost zero. The flexural modulus of the CNT-xGnP based epoxy composite continuously increased to 3.32 GPa with combined filler content up to 10 wt% while that of the CNT based epoxy composites slightly decreased to 1.96 GPa at 4 wt% CNT, and dropped to 1.57 GPa at 5 wt% loading, which is lower than that of epoxy. The CNT and CNT-xGnP samples had the same EMI SE at the same surface resistivity, because samples with the same surface conductivity have the same amount of the charge carriers.

The nesting behavior, reproduction, fruit set and shape of O. cornifrons varied significantly with the released sex ratio of O. cornifrons. A female : male sex ratio of 1 : 2 was resulted in a 3.4 to 6.7 fold higher than other sex ratio in a nesting behavior. A ratio of 1 : 2 resulted in a 1.2-fold nesting rate, which was slightly higher than other nesting rates. Releasing only males resulted in a 2.4-fold greater amount of fruit set in non-pollinated sites. A sex ratio of 1 : 2 gave a slightly higher shape index and a 1.2 to 1.6-fold lower asymmetric index than other sex ratios. There was no significant difference between female release numbers in fruit set, and 100 to 200 females gave a slightly higher shape index than 400 females. Thus, we determined that 200 females should be released per 2,000㎡ and that the sex ratio of females to males should be 1 : 2.

Multi-walled carbon nanotube (MWCNT)/polycarbonate (PC) nanocomposite was prepared by direct melt mixing to investigate the effect of the shear rate on the surface resistivity of the nanocomposites. In this study, an experiment was carried out to observe the shear induced orientation of the MWCNT in the polymer matrix using a very simple melt flow indexer with various loads. The compression-molded, should be eliminated. MWCNT/PC nanocomposite sample exhibited lower percolation thresholds (at 0.8 vol%) and higher electrical conductivity values than those of samples extruded by capillary and injection molding. Shear induced orientation of MWCNT was observed via scanning electron microscopy, in the direction of flow in a PC matrix during the extrusion process. The surface resistivity rose with increasing shear rate, because of the breakdown of the network junctions between MWCNTs. For real applications such as injection molding and the extrusion process, the amount of the MWCNT in the composite should be carefully selected to adjust the electrical conductivity.

A cell formation approach based on cluster analysis is developed for the configuration of manufacturing cells. Cell formation, which is to group machines and parts into machine cells and the associated part families, is implemented to add the flexibility and efficiency to manufacturing systems. In order to develop an efficient clustering procedure, this paper proposes a cluster analysis-based approach developed by incorporating and modifying two cluster analysis methods, a hierarchical clustering and a non-hierarchical clustering method. The objective of the proposed approach is to minimize intercellular movements and maximize the machine utilization within clusters. The proposed approach is tested on the cell formation problems and is compared with other well-known methodologies available in the literature. The result shows that the proposed approach is efficient enough to yield a good quality solution no matter what the difficulty of data sets is, ill or well-structured.

The attachment and adhesion of RAW 264.7 and MC3T3-E1 cells to titanium (Ti) discs with various degrees of roughness was investigated. The attachment, adhesion, and proliferation of these cells were evaluated after 4 hr, 24 hr and 7 day incubations. Both RAW 264.7 and MC3T3-E1 cells showed a time-dependant correlation between attachment and adhesion on the surface of the titanium discs. Both types of cells tended to have higher survival rate on these discs as the surface roughness increased. The percentage of adherent inflammatory RAW 264.7 cells was greater than MC3T3-E1 cells at 24 hr, but this was reversed at 7 days in culture. The morphology of osteoblastic MC3T3-E1 cells at 24 hr, determined using a surface emission microscope (SEM), appeared flattened and spread out while inflammatory RAW 264.7 cells were predominantly spherical in shape. The adhesion of both cell types on the titanium discs was dependant on the levels of fibronectin adsorbed on the disc surface, indicating that serum constituents modulate the efficient adhesion of these cells. Our data indicate that the cellular response to the titanium surface is dependent on the types of cells, surface roughness and serum constituents.

In this study, the internal structure of a Heumgyeonggak-nu (欽敬閣漏) was designed, and the power transmission mechanism was analyzed. Heumgyeonggak-nu is an automated water clock from the Joseon Dynasty that was installed within Heumgyeonggak (欽敬閣), and it was manufactured in the 20th year of the reign of King Sejong (1438). As descriptions of Heumgyeonggak-nu in ancient literature have mostly focused on its external shape, the study of its internal mechanism has been difficult. A detailed analysis of the literature record on Heumgyeonggak-nu (e.g., The Annals of the Joseon Dynasty) indicates that Heumgyeonggaknu had a three-stage water clock, included a waterfall or tilting vessel (欹器) using the overflowed water, and displayed the time using a ball. In this study, the Cheonhyeong apparatus, water wheel, scoop, and various mechanism wheels were designed so that 16 fixed-type scoops could operate at a constant speed for the water wheel with a diameter of 100 cm. As the scoop can contain 1.25 l of water and the water wheel rotates 61 times a day, a total of 1,220 l of water is required. Also, the power gear wheel was designed as a 366-tooth gear, which supported the operation of the time signal gear wheel. To implement the movement of stars on the celestial sphere, the rotation ratio of the celestial gear wheel to the diurnal motion gear ring was set to 366:365. In addition, to operate the sun movement apparatus on the ecliptic, a gear device was installed on the South Pole axis. It is expected that the results of this study can be used for the manufacture and restoration of the operation model of Heumgyeonggak-nu.

Seed color is an important factor affecting physiological and developmental process in wheat. One of the plant pigments, anthocyanins are a group of flavonoid compounds well known as pigments responsible for blue, purple, red, or yellow coloration of plant tissues. In this study, we investigated the pigmentation of purple and yellow color seed according to wheat grain developmental stages. The contents of anthocyanin and chlorophyll in the purple and yellow seeds were measured. Chlorophyll contents were changed similarly in both purple and yellow color seed, and no significant difference was observed between them. In purple color seed, the content of anthocyanin was significantly induced compared with yellow color seed. The individual anthocyanin components were investigated by ultra performance liquid chromatography (UPLC). Cyanidine-3-glucoside (C3G) and peonidine-3-glucoside (P3G) were detected as predominant anthocyanin in purple color wheat. To investigate whether structural genes in anthocyanin biosynthesis were involved in the trait differences between purple and yellow color seed, we examined the expression of anthocyanin biosynthesis-related genes (CHS, CHI, F3H, DFR, ANS, UFGT) and MYB transcription factor in developing wheat grains by using qRT-PCR. This study indicates that the expression of anthocyanin biosynthesis-related genes and MYB transcription factors correlate with anthocyanin levels of grain.

Space has many distinguishable characteristics from earth such as strong cosmic radiation, microgravity, supervaccum and weak magnetic field. For this reason, space environments can be used an efficient mutagen for plant breeding nowadays. To identify the affected genes by condition in space with outer space, Brachypodium seeds were placed in the Russia Segment (RS) Biorisk module of International Space Station (ISS). Brachypodium distachyon is a model system for temperature grass, because they represent the characteristics for annual winter grass. Seeds and organs of plants carried by satellite or spacecraft to space can be genetically mutated by exposing space environment. We performed a duplicated RNA sequencing to profile the differentially expressed genes. As a results, about 700 genes were upregulated and 250 genes were downregulated by cosmic environments, respectively. In the molecular function category, protein kinase and transcription activity related genes were upregulated. Among the many transcription factors (TFs), stress related TFs such as ERF, NAC and WRKY were differentially expressed in space exposed samples. In the future, their expression will be identified by using qRT_PCR.