• Journal of Positioning, Navigation, and Timing
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• 제8권4호
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• pp.201-208
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• 2019

Numerical integration is necessary for satellite orbit determination and its prediction. The numerical integration algorithm can be divided into single-step and multi-step method. There are lots of single-step and multi-step methods. However, the Runge-Kutta method in single-step and the Adams method in multi-step are generally used in global navigation satellite system (GNSS) satellite orbit. In this study, 4th and 8th order Runge-Kutta methods and various order of Adams-Bashforth-Moulton methods were used for GLObal NAvigation Satellite System (GLONASS) orbit integration using its broadcast ephemeris and these methods were compared with international GNSS service (IGS) final products for 7days. As a result, the RMSE of Runge-Kutta methods were 3.13m and 4th and 8th order Runge-Kutta results were very close and also 3rd to 9th order Adams-Bashforth-Moulton results. About result of computation time, this study showed that 4th order Runge-Kutta was the fastest. However, in case of 8th order Runge-Kutta, it was faster than 14th order Adams-Bashforth-Moulton but slower than 13th order Adams-Bashforth-Moulton in this study.

• Journal of Aerospace System Engineering
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• 제8권2호
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• pp.40-48
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• 2014

In this paper, a prototype of GPS jammer localization system for precise landing is developed. The jammer localization system consists of the four jamming signal receivers for collecting RF signal, one central tracking station for estimating jammer position, and one monitoring station for displaying estimated position on the map. In order to estimate jammer location TDOA and AOA algorithm are introduced, and the function and design parameters of the developed prototype are proposed. CW, DSSS, Swept CW jamming signals were generated and used. From the results, it can be confirmed that developed system meets the performance goal.

• Journal of the Korean Medical Association
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• 제61권11호
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• pp.680-686
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• 2018

Acne vulgaris is a very common condition affecting up of about 80% to 90% of adolescents. The patients with acne have been shown to be adversely impacted by the effect of acne on their quality of life. Four factors are believed to play a key role in the development of acne lesions: excess sebum production, disturbed keratinization within the follicle, colonization of the pilosebaceous duct by Propionibacterium acnes, and the release of inflammatory mediators into the skin. Consequently, the target for acne therapy is these well-known pathogenic factors responsible for this disease state. Topical retinoids correct abnormal keratinization, but it should be applied cautiously because of irritation. Benzoyl peroxide is an effective bactericidal agent against P. acnes. Main topical antibiotics are erythromycin and clindamycin. Fixed combination topical products with retinoids, benzoyl peroxide and antibiotics have been introduced. Use of systemic antibiotics, including tetracyclines and macrolides rapidly improves inflammatory acne lesions. Oral isotretinoin is effective against all of the main pathogenic features of acne but is contraindicated in pregnant women and has been associated with cheilitis and dry skin. Hormonal therapy has been found to improve acne in some selective patients and should be considered for appropriate candidates. This review will present the general aspects of the pharmacological treatments for acne.

• Journal of Microbiology and Biotechnology
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• 제31권5호
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• pp.637-644
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• 2021

Malassezia is the most abundant genus in the fungal microflora found on human skin, and it is associated with various skin diseases. Among the 18 different species of Malassezia that have been identified to date, M. restricta and M. globosa are the most predominant fungal species found on human skin. Several studies have suggested a possible link between Malassezia and skin disorders. However, our knowledge on the physiology and pathogenesis of Malassezia in human body is still limited. Malassezia is unable to synthesize fatty acids; hence, it uptakes external fatty acids as a nutrient source for survival, a characteristic compensated by the secretion of lipases and degradation of sebum to produce and uptake external fatty acids. Although it has been reported that the activity of secreted lipases may contribute to pathogenesis of Malassezia, majority of the data were indirect evidences; therefore, enzymes' role in the pathogenesis of Malassezia infections is still largely unknown. This review focuses on the recent advances on Malassezia in the context of an emerging interest for lipases and summarizes the existing knowledge on Malassezia, diseases associated with the fungus, and the role of the reported lipases in its physiology and pathogenesis.

• Journal of Microbiology and Biotechnology
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• 제32권11호
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• pp.1390-1395
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• 2022

Acne is a chronic inflammatory disease of the sebaceous gland attached to the hair follicles. Cutibacterium acnes is a major cause of inflammation caused by acne. It is well known that C. acnes secretes a lipolytic enzyme to break down lipids in sebum, and free fatty acids produced at this time accelerate the inflammatory reaction. There are several drugs used to treat acne; however, each one has various side effects. According to previous studies, sulforaphene (SFEN) has several functions associated with lipid metabolism, brain function, and antibacterial and anti-inflammatory activities. In this study, we examined the effects of SFEN on bacterial growth and inflammatory cytokine production induced by C. acnes. The results revealed that SFEN reduced the growth of C. acnes and inhibited proinflammatory cytokines in C. acnes-treated HaCaT keratinocytes through inhibiting NF-κB-related pathways. In addition, SFEN regulated the expression level of IL-1α, a representative pro-inflammatory cytokine expressed in co-cultured HaCaT keratinocytes and THP-1 monocytes induced by C. acnes. In conclusion, SFEN showed antibacterial activity against C. acnes and controlled the inflammatory response on keratinocytes and monocytes. This finding means that SFEN has potential as both a cosmetic material for acne prevention and a pharmaceutical material for acne treatment.

• Proceedings of the SCSK Conference
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book I
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• pp.73-84
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• 2003

Skin aging process on pre-menopausal women is a problem that needs to be prevented as early as possible. The decrease of oestrogen level which is one of the intrinsic factors of the skin aging process will affect the skin biological process, due to oestrogen receptors on the skin. A number of researches conducted on pre-menopausal women with the allocation of oestrogen hormone resulted in delaying the skin aging process. The administration of soy isoflavon, a phytoestrogen found in daily food, on pre-menopausal women is hoped to be able to prevent skin aging process, even clinically or molecular biologically. This research aims to explain the benefit of administering of soy isoflavon on skin aging process. The design of the research is randomised controlled trial (RCT). As many as 60 pre-menopausal women were collected with simple random sampling method. Soy isoflavon is an independent variable, while skin aging process is a dependent variable assessed from the hydration, sebum level, average roughness, depth of wrinkles, skin clarity, length of the telomere. Analysis was conducted using t and MANDVA tests and.the result showed a significance (F = 10,439; p = 0,001) over the allocation of soy isoflavon to the whole variable dependent, including the telomere length and the skin hydration, meant that allocation of soy isoflavon could delay skin aging process.

• Journal of Fashion Business
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• 제13권6호
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• pp.45-60
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• 2009

This study examined the efficacy of restraining the increase of the bacteria colony of scalp according to the application of the Ayurvedic base oils and essential oils to scalp and hair. The result is as follows. The experiment illustrated that as the result of doing the paired sample t-test of a treated group and a control group according to constitutional oiling, the efficacy of the statistically significant decrease of the colony manifested in six tested groups except the group of Pitta constitution to which sesame and lavender were applied. Also, in a group that sesame was applied to Vata constitution and a group that coconut and lavender were applied to Pitta constitution, according to the passage of time, the result of being reduced the number of the colony was obtained and it showed that the oiling suitable for each constitution has the efficacy to decrease the colony of scalp. At the same time, regardless of the constitutions, the application of oils also showed the efficacy of restraining the increase of the bacteria colony of scalp. As the result of performing Paired Sample t-test for the subjective evaluation of the subjects in pre and post clinical testing, In the analysis of questionnaire that were obtained before and after the clinical testing, the results of all of the items except the item questioning a degree of inflammation appeared to be significant. That is to say, the subjects answered that a degree of keratin or a pain in scalp, an amount of sebum and a degree of hair damage were decreased after the application of oil more than before it. And in the question of a degree of hair damage, the application of oils were proved as having the efficacy to improve the hair damage.

• Journal of Positioning, Navigation, and Timing
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• 제4권4호
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• pp.173-180
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• 2015

In this study, an algorithm that detects a spoofing signal for a GPS L1 signal was proposed, and the performance was verified through RF spoofing signal simulation. The proposed algorithm determines the reception of a spoofing signal by detecting a correlation distortion of GPS L1 C/A code caused by the spoofing signal. To detect the correlation distortion, a detection criterion of a spoofing signal was derived from the relationship among the Early, Prompt, and Late tap correlation values of a receiver correlator; and a detection threshold was calculated from the false alarm probability of spoofing signal detection. In this study, an RF spoofing environment was built using the GSS 8000 simulator (Spirent). For the RF spoofing signal generated from the simulator, the RF spoofing environment was verified using the commercial receiver DL-V3 (Novatel Inc.). To verify the performance of the proposed algorithm, the RF signal was stored as IF band data using a USRP signal collector (NI) so that the data could be processed by a CNU software receiver (software defined radio). For the performance of the proposed algorithm, results were obtained using the correlation value of the software receiver, and the performance was verified through the detection of a spoofing signal and the detection time of a spoofing signal.

• Journal of Haehwa Medicine
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• 제21권1호
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• pp.1-9
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• 2012

Objectives : The aim of this experiment is to find out relationship between the effect of cosmetics and 4 types of pattern identification about fluid-humor, which are based on the general idea of traditional oriental medicine, Qi-Blood and deficiency-excess. Methods : Korean female volunteers in good health (n=25, $23.12{\pm}2.83$) participated in this experiment. Three Korean medical doctors classified them into 4 groups: Blood-deficiency: group A; Blood-excess: group B; Qi-deficiency:group C; Qi-excess:group D). Cosmetics that contains herb extract for Blood deficiency were given to all volunteers and they used the cosmetics for 4 weeks. Volunteers were assessed non-invasively with the skin measuring devices before and after using cosmetics. And we analyzed the correlation of skin physiological parameters with 4 groups. Results : Three doctors diagnosed participants and classified them into 4 groups ; group A(n=8),group B(n=7), group C(n=3), group D(n=5) as highest score. After 4 weeks, facial skin moisture showed no significant difference in comparison between 4 groups. Sebum showed significant increase in Group A and significantly decreased Group B. Measurement of facial skin elasticity tended to increase in Group A, C, D but skin elasticity was decreased significantly in Group B. Conclusions : In case of a group that pattern identification about fluid-humor corresponds to herb extract in cosmetic, skin improving effect was better than the other group that pattern identification oppose to properties of herb in cosmetic. Therefore, from the view of traditional oriental medicine, it is very important to understand user's pattern of identification or physical conditions and properties of herbs in cosmetics on the matter of safety and efficacy.