• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.1
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• pp.43-56
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• 2012

Wireless sensor networks consist of numerous small-sized nodes equipped with limited computing power and storage as well as energy-limited disposable batteries. In this networks, nodes are deployed in a large given area and communicate with each other in short distances via wireless links. For energy efficient networks, dynamic clustering protocol is an effective technique to achieve prolonged network lifetime, scalability, and load balancing which are known as important requirements. this technique has a characteristic that sensing data which gathered by many nodes are aggregated by cluster head node. In the case of cluster head node is exposed by attacker, there is no guarantee of safe and stable network. Therefore, for secure communications in such a sensor network, it is important to be able to encrypt the messages transmitted by sensor nodes. Especially, cluster based sensor networks that are designed for energy efficient, strongly recommended suitable key management and authentication methods to guarantee optimal stability. To achieve secured network, we propose a key management scheme which is appropriate for hierarchical sensor networks. Proposed scheme is based on polynomial key pool pre-distribution scheme, and sustain a stable network through key authentication process.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.29 no.1
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• pp.15-25
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• 2023

Since the COVID-19 crisis, the use of disposable packaging materials and delivery services, which raise environmental and social issues with waste disposal, has significantly increased. Antimicrobial active packaging has emerged as a viable solution for extending the shelf-life of foods by minimizing microbial growth and decomposition. In this review article, we provide a comprehensive overview of current research trends in antimicrobial active film and coating published over the last five years. First, we introduced various polymer materials such as film and coating that are used in active packaging. Next, various types of antimicrobial (antibacterial, antifungal, and antiviral) packaging including essential oil, extracts, biological material, metal, and nanoparticles were introduced and their activities and mechanisms were discussed. Finally, the current challenges and prospects were discussed. Overall, this review provides insights into the recent advancements in antimicrobial active packaging research and highlights the potential of the technology to enhance food safety and quality.

• Korean journal of applied entomology
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• v.26 no.2 s.71
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• pp.71-81
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• 1987

This study was conducted to study the effects of temperature on the oviposition, feeding and emergence of the azuki bean weevil(ABW) (Callesobruchus chinensis L.) in the stored beans. And ovipositional preference, hatching and emergence on the preference and non-preference hosts were also investigated. ABW has four generations a year and overwinters as larva stage in the bean grains. Optimum oviposition temperature of the ABW ranges from $25^{\circ}C\;to\;30^{\circ}C$. Oviposition preference in different hosts was in the order of azuki bean, mung bean, soy bean, kidney bean, black-soybean, pea. At $25^{\circ}C$, optimum development temperature emergence of period the ABW averaged 29 days on azuki bean, 31 days on mung bean, 49 days on soy bean, 46 days on black-soybean, 34 days on Pea. Percent hatch in different hosts was in the order of azuki bean, mung bean, soy bean, pea, black-soybean, kidney bean. But percent emergence was in the order of azuki bean, mung bean, pea, black-soybean, kidney bean. Especially, in azuki bean and mung bean, percentage of hatching and emergence was very high. And in soy bean and black-soybean, percentage of hatching was high but emergence was low. The kidney bean was hatching but not emergence at all. The longevity at the different temperatures appeared to be $4{\sim}5$ days at $35^{\circ}C,\;5{\sim}7$ days at $25^{\circ}C{\sim}30^{\circ}C$, $10{\sim}15$ days at $20^{\circ}C\;and\;19{\sim}24$ days at $15^{\circ}C$. Kidney bean of feeding non-preference host oviposited at Seed coat and Endosperm, but no larva developed. And cotyledon and embryo parts were not oviposited at all. The percentage of germination of egg laid bean grain and damaged bean grains was low. Especially, the percentage of germination of damaged bean grains was 0% on azuki bean, 5% on black-soy bean, 7% on Pea.

• Food Science and Preservation
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• v.30 no.6
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• pp.1095-1106
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• 2023

This study investigated the anti-oxidative and anti-inflammatory effects of Aster glehni (AG) extract in RAW 264.7 cells and Caenorhabditis elegans. The total polyphenol and flavonoid contents were higher in the ethanol extracts than in the hot water extracts. As a result of measuring the moisture contents (%) and extraction yields (%) of AG and drying A. glehni for processing (DAG), 70% ethanol, which has the highest percentage of extraction yield, was selected as the final solvent. DPPH radical scavenging activity showed higher antioxidant activity of ethanol extracts of DAG than AG. The cytotoxicity assay of the AG or DAG ethanol extracts was treated at different concentrations (25, 50, and 100 ㎍/mL), and cell viability rates were higher than 80% at all concentrations. The LPS-stimulated nitric oxide (NO) production in RAW 264.7 was significantly reduced at all concentrations of AG and DAG groups. As a result of measuring the gene expression of iNOS, which induces NO production, the AG or DAG group decreased by 33% and 32%, compared with the phosphate buffer saline (PBS) group. Under inflammatory stress conditions, the survival rate of C. elegans treated with AG or DAG ethanol extract with LPS showed concentration-dependent improvement in survival rate compared with the PBS group. Considering these results, AG could potentially be developed as an antioxidant and anti-inflammatory functional food material.

• Archives of design research
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• v.20 no.3 s.71
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• pp.279-288
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• 2007

Today, design is not free from fashion, which emerges and vanishes temporarily, and aims at equalization. As a result, products quickly become obsolete because of fashion. This means that the span of products is determined by a social concept, which is not clarified, regardless of their functions. Usable products will gradually disappear from us and it will cause serious environmental problems, unless we can find out measures against fashion. As such, it is important to study the characteristics of the shaker's design in this circumstance. The Shaker's community has a distinguishable difference from other general societies. Temporary fashion and misled information cannot interfere with their consciousness. Religion, the life and the principle of design have developed on the same level in their community. Especially, any decoration or the difference of materials is not allowed in shaker's design. It reflects their thinking that all people are equal in the sight of God. Therefore, any decoration for social and economical superiority can not be used. Through this consciousness, they can be free from fashion or decoration. They, also, believe that they can reach perfection through practicality and simplicity. The reason why shaker's design is not disturbed by fashion is that their belief is involved in their design. Consequently, if religious or conscious contents are primarily set up, design can be free from fashion and products can be used for a long time.

• Korean journal of communication and information
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• v.43
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• pp.247-281
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• 2008

The purpose of this article is to re-examine the issue of Chobo's origin, which has not been clearly determinated thus far. Also, the research investigates Chobo's name, time point of discontinuance, character of the article on disaster, and civil-printed incident of Chobo during King Sunjo. As an internal bulletin, handwritten Chobo began to come out at the end of 15th century, roughly King Sungjong period of Chosun Dynasty. Systematically developed in the period of King Jungjong, it had continuously been released until November, 1907 when fairly organized and competitive commercial daily newspapers were published and when the office of secretary named Biseogam was abolished. Because handwritten Chobo was exclusive and narrow in its communication nature and difficult to read it's fast handwritten Nancho calligraphic style, in August, 1577 (10th year of King Sunjo) a few civilian in Seoul obtained a permission from authorities (Uijungboo and Sahunboo) published a wooden type printed Chobo. Unfortunately, privately printed Chobo was forced to cease in 3 month because of King Sunjo's oppressive measure. However, considering it was published for a profit by civilian and used the world's first type printing, it is highly probable that Chobo seems to be the world’s first type printing commercial daily newspaper.

• Korean Journal of Remote Sensing
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• v.14 no.3
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• pp.213-222
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• 1998

Electro-Optical Camera(EOC) is the main payload of the KOrea Multi-Purpose SATellite(KOMPSAT) with the mission of cartography to build up a digital map of Korean territory including a Digital Terrain Elevation Map(DTEM). This instalment which comprises EOC Sensor Assembly and EOC Electronics Assembly produces the panchromatic images of 6.6 m GSD with a swath wider than 17 km by push-broom scanning and spacecraft body pointing in a visible range of wavelength, 510~730 nm. The high resolution panchromatic image is to be collected for 2 minutes during 98 minutes of orbit cycle covering about 800 km along ground track, over the mission lifetime of 3 years with the functions of programmable gain/offset and on-board image data storage. The image of 8 bit digitization, which is collected by a full reflective type F8.3 triplet without obscuration, is to be transmitted to Ground Station at a rate less than 25 Mbps. EOC was elaborated to have the performance which meets or surpasses its requirements of design phase. The spectral response, the modulation transfer function, and the uniformity of all the 2592 pixel of CCD of EOC are illustrated as they were measured for the convenience of end-user. The spectral response was measured with respect to each gain setup of EOC and this is expected to give the capability of generating more accurate panchromatic image to the users of EOC data. The modulation transfer function of EOC was measured as greater than 16 % at Nyquist frequency over the entire field of view, which exceeds its requirement of larger than 10 %. The uniformity that shows the relative response of each pixel of CCD was measured at every pixel of the Focal Plane Array of EOC and is illustrated for the data processing.