• Korean Chemical Engineering Research
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• v.49 no.1
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• pp.101-104
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• 2011

Cellobiose dehydrogenase(CDH) as a hemoflavoenzyme is secreted out of cell in the cellulose degradation. As CDH strongly bound to amorphous cellulose, it helps cellulose hydrolysis by cellulase. CDH may have an important role of saccharification process for bioethanol production. In this study, Phanerochaete chrysosporium ATCC 32629 was selected for the production of CDH among other strains tested. The optimal temperature and pH of CDH produced by P. chrysosporium ATCC 32629 were ${55^{\circ}C}$ and 4, respectively. To improve the activity of CDH, the mutation of P. chrysosporium was performed using proton beam that has high energy level partially. As a result, P. chrysosporium mutant with the high activity was selected at 1.2 kGy in a range of 99.9% lethal rate. The CDH and $\beta$-glucosidase activities of mutant were 1.4 fold and 20 fold higher than those of wild strain. Therefore, P. chrysosporium mutant with the high activities of CDH and $\beta$-glucosidase was obtained from mutation by proton beam irradiation.

• Journal of Ginseng Research
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• v.20 no.4
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• pp.501-519
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• 1996

There are two kinds of commercially available ginseng root, red ginseng and white ginseng processed from fresh ginseng root Those ginsengs are primary product from fresh ginseng root and have the characteristic of keeping their original root shape Processed ginseng products are made from either red ginseng or white ginseng by way of complicated process of pulverization. Extraction. Condensation, fettering, sterilization, etc. Among them there are extracts. extract powder, powder, capsules tablets, Candy, drinks, nectar, jelly, gums. chicken soup. tonic. etc. to meet the demand for consumer's pretheronce . The 200 kinds of processed secondary products are approximately produced in the form of 20 kinds of ginseng products by about 60 domestic companies. In spite of about 213.000 million won of domestic market in 1993. it seems like that the ginseng market of the future has not a good prospects The total market sale of white ginseng in Korea has been continuously decreased since 1991 And 963 tons of white ginseng was consumed in domestic market in 1993 The domestic market sales of white ginseng in origina1 root shave. was 90, 000 million won in 1993 and market price of the fine root used as a source of processed products has not been changed in these ten years. The total market sale of red ginseng and its processed products was 58, 000 million won in 1993 9.800 mi11ion won of red ginseng in original root shape and 48.000mi11ion of processed red ginseng product. Ginseng products such as extracts, drinks, teas and tonics etc atre mostly exported to south-east Asia. And the total exports of ginseng pi.oducts (extracts, drinks teas) decreased to 54 million dollars in 1994, compared with 85 million dollars in 1992. Despite of extensive knowledge about ginseng little is still known about the development of new processed ginseng pl.oducts because of "Know-How". Some papars have presented the effects of extracting method(amounts of solvent. time. temperature, equipment. etc.) on the quality and yields of ginseng extr acts. Also. some researchers have carried out a few studies on the poriflcation of the extracts and the amounts of precipitation in the drink at variotas pH during the storage for preventinly drink from precipitation. A fell studies on the preservation of Korean ginseng powder. tea. Extract powder by irradiation and ozone treatment have been reported by some researcher for the improvement hygienic quality of ginseng products There are also some reports about the effects of ginseng components on the acid production by lactic acid bacteria or acetic acid bacteria. and alcohol production by yeast for the development of new ginseng products processed by fermentation. To make ginseng more able to contribute to the health of mankind in the future. consistent and considerable efforts should be focussed on improving the taste of ginseng and developing various new product as a health food or a function food.tion food.

• Resources Recycling
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• v.18 no.1
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• pp.38-43
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• 2009

In this study, binderless consolidation processes of ultra foe Si powder, by-products of making high purity poly-Si in the current method, were systematically investigated for use as economical solar-grade feedstock. The average diameter of the silicon powder was $7.8{\mu}m$. The main contaminants of the fine silicon powder were $SiO_2$ type oxide and humidity. The chemical pretreatment using the HF solution was observed to be effective for the improvement of the compactability of the silicon powder and the density ratio and the strength of the silicon powder compacts. The yield of the binder-free consolidation process increased by 20% under a vacuum condition. In as-received state, the silicon powder were not pure enough to be used as solar grade feed-stock material. After the dry chemical treatments, a sufficiently high purity above solar-grade was able to be achieved.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.558-564
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• 2021

The water purifier market has increased rapidly in recent years. The welding technology of the evaporator is a key component that determines the level of ice production and the cold water performance of an ice purifier. The finger type evaporator of an ice purifier can remove ice and is divided largely into an instant heat method and a hot gas method. In the hot gas type evaporator, particularly during the production process, the pinhole phenomenon inside the copper pipe and clogging problems occur intermittently when welding high-pressure pipes due to the high-temperature oxygen welding. Its use in a water purifier can cause a problem in that ice and cold water do not form, and repairs cannot be made on site. To solve this problem, in this study, a cap jig was applied to improve the welding defect of the hot gas evaporator. In addition, the oxygen welding flame size was adjusted so that the heat source could be well supplied to the cap jig, and the effectiveness was confirmed through a wave pressure test, a test, and a thermal shock test.

• Journal of Industrial Convergence
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• v.22 no.4
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• pp.1-9
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• 2024

Smart factories represent production facilities where cutting-edge information and communication technologies are fused with manufacturing processes, reflecting rapid advancements and changes in the global manufacturing sector. They capitalize on the integration of robotics and automation, the Internet of Things (IoT), and the convergence of artificial intelligence technologies to maximize production efficiency in various manufacturing environments. However, the smart factory environment is prone to security threats and vulnerabilities due to various attack techniques. When security threats occur in smart factories, they can lead to financial losses, damage to corporate reputation, and even human casualties, necessitating an appropriate security response. Therefore, this paper proposes a security authentication mechanism for safe communication in the smart factory environment. The components of the proposed authentication mechanism include smart devices, an internal operation management system, an authentication system, and a cloud storage server. The smart device registration process, authentication procedure, and the detailed design of anomaly detection and update procedures were meticulously developed. And the safety of the proposed authentication mechanism was analyzed, and through performance analysis with existing authentication mechanisms, we confirmed an efficiency improvement of approximately 8%. Additionally, this paper presents directions for future research on lightweight protocols and security strategies for the application of the proposed technology, aiming to enhance security.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.5
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• pp.635-643
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• 2018

This paper propose a method to identify the motor parameters and improve input voltage error which affect the low speed position error of the back-emf(back electromotive force) based sensorless algorithm and to secure the operation reliability and stability even in the case where the load fluctuation is severe and the start and low speed operation frequently occurs. In the model-based observer used in this paper, stator resistance, inductance, and input voltage are particularly influential factors on low speed performance. Stator resistance can cause resistance value fluctuation which may occur in mass production process, and fluctuation of resistance value due to heat generated during operation. The inductance is influenced by the fluctuation due to the manufacturing dispersion and at a low speed where the change of the current is severe. In order to find stator resistance and inductance which have different initial values and fluctuate during operation and have a large influence on sensorless performance at low speed, they are commonly measured through 2-point calculation method by 2-step align current injection. The effect of voltage error is minimized by offsetting the voltage error. In addition, when the command voltage is used, it is difficult to estimate the back-emf due to the relatively large distortion voltage due to the dead time and the voltage drop of the power device. In this paper, we propose a simple circuit and method to detect the voltage by measuring the PWM(Pulse Width Modulation) pulse width and compensate the voltage drop of the power device with the table, thereby minimizing the position error due to the exact estimation of the back-emf at low speed. The suitability of the proposed algorithm is verified through experiment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.613-619
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• 2017

Recently, the development and production of weapons systems for military products have been increasing. Therefore, there is a need for an efficient quality control method suitable for limited resources and manpower for the manufactured military products. Military munitions are characteristically developed and produced as business contract units. In addition, business and quality control are done by contract. For this reason, many contracts are concluded in one producer and similar products are often produced. Business and quality control also require extensive manpower and effort. If a company produces several similar products, a more efficient management approach is required. This study therefore examines these problems in an attempt to present solutions by analyzing the types of munitions contracts and the characteristics of products produced by one company. Based on the results, a method is proposed to manage the contract-specific management methods by company, that is, by business site. The method is applied to an engine manufacturing company and the integrated management plan is verified and its effectiveness confirmed. The effect of facility-wide method was a reduction of QA manpower and an improvement in maintaining quality assurance and stability through management of the workforce and contract grouping method.

• The Korean Journal of Food And Nutrition
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• v.19 no.3
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• pp.288-295
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• 2006

This study was conducted to examine the possibility of improvement effect in suppression of precipitation and nasty smell creation in Takju mash. First of all, gum shown to be lowest precipitation velocity was selected and this was applied to the fermentation of Takju mash for comparing with the control in terms of fermentation aspects and various qualities of Takju mash. Precipitation amount and precipitation velocity of suspension in Takju mash added with carrageenan was shown to be the lowest than that of others. Compared with the control, alcohol was highly generated in Takju mash added with carrageenan, especially between two and four days. Total acidity was shown to be highly increased until 2 days in Takju mash and thereafter to be slightly increased. Takju mash added with carrageenan was shown to be lower on the second stage than the control. Fusel oil produced from mash added with carrageenan was 0.046${\sim}$0.113${\mu}$l/ml and mash added with carrageenan generated less fusel oil than the control by 1.6${\sim}$3.2 fold. Yeast growth on the mash added with carrageenan was revealed to be helpful during fermentation periods. In general, sensory characteristics of Takju mash were shown to be more superior in mash added with carrageenan than in other samples. While nasty smell produced from a sample without gums was perceived after 2 days of Takju mash storage, nasty smell of Takju mash added with carrageenan was recognized after 6 days during storage. In conclusion, precipitation of suspension and nasty smell production in Takju mash were found to be suppressed by addition of carrageenan during Takju fermentation.

• Applied Biological Chemistry
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• v.20 no.1
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• pp.95-100
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• 1977

To get a basic information for improving Korean's pattern of comsuming red pepper and the possibility of its industrial production, consumer's ways of red pepper processing and his present dietary habits were surveyed and the results are follows; (1) Korean's daily consumption of red pepper was on the average 9.2 g on the basis of the whole dried red pepper. (2) The tendency of evading the home drying method was increased; 72.22% in urban community and 50.4% in rural community purchased the dried red pepper in the lump yearly. The household purchasing the fresh red pepper and using the home drying was 27.8% in urban community and 49.6% in rural community, so one third of urban household was still using the home drying method. The case of dependence on tine drying factory was no more than 2.6%. (3) Drying method was mainly sun drying which done on the poor circumstance like as the street side without the proper equipment of drying. Home process of red pepper by housewife was 70.8%, and the old, housekeeper were only 7.3% respectively. (4) The hygienic sense in the drying was rare; 68.8% was not washed and 51.9% of decayed red pepper was eaten. (5) Koreans prefered the strong pungency, deep red color and fine powder form. (6) While the 45.5% of seed was collected by second hand dealer and made use of as resources of edible oil, it was not used effectively due to complexity of its collection system. (7) While 40.1% desired the improvement of red pepper dietary life, 41.1% distrusted the present commercial red pepper powder on the market. From the results above, we conclude the fact many households have still hygienically poor red pepper processed at home, in spite of the red pepper is one of the most important spices in Korea. Considering the growing urban population, reduction of unemployed labor due to the increasing nuclear family and hygienic problems caused by the serious pollution, the improvement of red pepper processing method is urgently required. And it is believed that red pepper has a good prospect to be processed on the industrial scale in Korea.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.86-92
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• 2016

A high-capacity battery installed in a hybrid vehicle or electric vehicle is used to power, or as a power supply for, electric sub-assemblies. In order to use a high-capacity battery as a power supply for electric sub-assemblies, such as an electronic control unit or for lighting, radio, and navigation, there is a need for a DC converter that changes a high voltage of 240-400V to a low voltage of 12-14V, which is done with a low-voltage DC-DC converter (LDC). An LDC undergoes long-term aging so as to reduce latent defects in the production process. With regard to the usual aging method, an LDC is a DC-DC converter. So, a DC power supply is connected and used as input, and a programmable DC electronic load is the output. For stable operation, a product having a larger capacity by 10% (compared to an LDC) is used, and has a structure where electric power is dissipated into 100% heat. So, there is a problem with volume, based on the use of two pieces of equipment to test the LDC, and another problem based on the generation of heat in the programmable DC electronic load. Hence, this paper suggests a load test method as a way of recycling, where a significant portion of the electricity dissipated as heat in a load tester is returned as input. The method realizes savings of 80% or more in the electricity dissipated as heat through improvement in the efficiency of the recycling load tester.