• Korean Journal of Pharmacognosy
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• v.43 no.4
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• pp.323-327
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• 2012

Acne, also known as Acne vulgaris, is a common disorder of human skin involving the sebaceous gland and Propionibacterium acnes (P. acnes). The purpose of this study was to demonstrate whether anti-acne herbal complex (AAHC), a functional extract from herbal complex can be used for acne treatment as a natural product. We first demonstrated anti-acne activity of AAHC in mouse acne model. Acne was induced by injecting P. acnes on the backside $2{\times}10^7$ CFUs in ICR mice and then the mice were treated with AAHC by dermal application once daily. ACFREE$^{(R)}$ (clindamicin phosphate) was used as a positive control. Treatment with AAHC decreased the P. acnes-induced skin swelling and inflammation. AAHC treatment significantly decreased serum DHT concentration in acne-induced mice. Especially, treatment of 20% AACH in mice was more effected than 40%. We next evaluated the antimicrobial property of AAHC against P. acnes, Staphylcococcus aureus (S.aureus), and Escherichia coli (E. coli). Incubation of P. acnes, S. aureus, and E. coli with AAHC showed minimal inhibitory concentration (MIC) values against the bacterial growth lower. Alamar blue method was also carried for the antibacterial activity. It was effectively MIC level at 6.25% of P. acnes. AAHC effectively inhibited the growth of S. aureus and E. coli at 0.097% on MIC level, respectively. Our results showed the potential of using AAHC as an alternative treatment for antibiotic therapy of acne and the application of AAHC as a herbal medicine for acne treatment.

• Journal of Powder Materials
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• v.23 no.4
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• pp.307-310
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• 2016

$TiOF_2$, which has remarkable electrochemical and optical properties, is used in various applications such as Li-ion batteries, electrochemical displays, and photocatalysts. In addition, it is possible to utilize the template which is allowed to synthesize fluorine doped $TiO_2$ powders with hollow or faceted structures. However, common synthesis methods of $TiOF_2$ powders have some disadvantages such as the use of expensive and harmful precursors and batchtype processes with a limited production scale. In this study, we report a synthetic route for preparing $TiOF_2$ powders by using an inexpensive and harmless precursor and a continuous ultrasonic spray pyrolysis process under a controlled atmosphere to address the aforementioned problems. The synthesized powder has an average size of $1{\mu}m$, a spherical shape, a pure $TiOF_2$ phase, and exhibits a band-gap energy of 3.2 eV.

• Earthquakes and Structures
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• v.7 no.1
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• pp.39-55
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• 2014

A modified procedure is presented for assessing the seismic response of elastic non-proportionate multistory buildings. This procedure retains the simplicity of the methodology presented by the author in earlier papers, but it presents higher accuracy in buildings composed by very dissimilar types of bents. As a result, not only frequencies and peak values of base resultant forces are determined with higher accuracy, but also the location of the first mode center of rigidity (m1-CR). The closeness of m1-CR with the axis passing through the centers of floor masses (mass axis) implies a reduced rotational response and it is demonstrated that in elastic systemsa practically translational response is obtained when this point lies on the mass axis.Besides, when common types of buildings are detailed as planar structures under a code load, this response is maintained in the inelastic phase of their response as a result of the almost concurrent yielding of all the resisting bents. This property of m1-CR can be used by the practicing engineer as a guideline to form a structural configuration which will sustain minimum rotational response, simply by allocating the resisting elements in such a way that this point lies close to the mass axis. Inelastic multistory building structures, detailed as above, may be regarded as torsionally balanced multistory systems and this is demonstrated in eight story buildings, composed by dissimilar bents, under the ground motions of Kobe 1995 (component KJM000) and Friuli 1976 (component Tolmezzo E-W).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.1
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• pp.139-149
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• 2007

Asynchronous OFCDM(Orthogonal Frequency and Code Division Multiplexing) systems must have a cell search process necessarily unlike synch개nous systems. this process is hewn initial synchronization and a three-step cell search algorithm is performed for the initial synchronization in the following three steps: OFCDM symbol timing, i.e., Fast Fourier Transform(FFT) window timing is estimated employing guard interval (GI) correlation in the first step, then the frame timing and CSSC(Cell Specific Scrambling Code) group is detected by taking the correlation of the CPICH(Common Pilot Channel) based on the property yielded by shifting the CSSC phase in the frequency domain. Finally, the CSSC phase within the group is identified in the third step. This paper proposes a modification group code with two or three block of the conventional CPICH based cell search algorithm in the second step which offers MS(Mobile Station) complexity reductions. however, the effect of the reduction complexity leads to degradation of the performance therefore, look for combination to have the most minimum degradation. the proposed block type group code with suitable combinations is the nearly sane performance as conventional group code and has a complexity reduction that is to be compared and verified through the computer simulation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.151-156
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• 1995

This paper presents a methodology for real-time detecting and identifying the runout geometry of an end mill. Cutter runout is a common but undesirable phenomenon in multi-tooth machining such as end-milling process because it introduces variable chip loading to insert which results in a accelerated tool wear,amplification of force variation and hence enlargement vibration amplitude. Form understanding of chip load change kinematics, the analytical sutting force model was formulated as the angular domain convolution of three dynamic cutting force component functions. By virtue of the convolution integration property, the frequency domain expression of the total cutting forces can be given as the algebraic multiplication of the Fourier transforms of the local cutting forces and the chip width density of the cutter. Experimental study are presented to validata the analytical model. This study provides the in-process monitoring and compensation of dynamic cutter runout to improve machining tolerance tolerance and surface quality for industriql application.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.6 s.348
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• pp.1-8
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• 2006

In the asynchrous OFCDM(Orthogonal Frequency and Code Division Multiplexing) system, a three-step cell search algorithm is performed for the initial synchronization in the following three steps: OFCDM symbol timing, i.e., Fast Fourier Transform(FFT) window timing is estimated employing guard interval (GI) correlation in the first step, then the frame timing and CSSC (Cell Specific Scrambling Code) group is detected by taking the correlation of the CPICH(Common Pilot Channel) based on the property yeilded by shifting the CSSC phase in the frequency domain. Finally, the CSSC phase within the group is identified in the third step. This paper proposes a modification code(PCSSCG:Patial Cell Specific Scrambling Code Group) of the conventional CPICH based cell search algorithm in the second step which offers MS(Mobile Station) complexity reductions with the nearly same performance. The proposed method is to be compared and verified through the computer simulation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.11
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• pp.4372-4394
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• 2020

The distribution of popular videos incurs a large amount of traffic at the base stations (BS) of networks. Device-to-multi-device (D2MD) communication has emerged an efficient radio access technology for offloading BS traffic in recent years. However, traditional studies have focused on synchronous user requests whereas asynchronous user requests are more common. Hence, offloading BS traffic in case of asynchronous user requests while considering their time-varying characteristics and the quality of experience (QoE) of video request users (VRUs) is a pressing problem. This paper uses social stability (SS) and video loading duration (VLD)-tolerant property to group VRUs and seed users (SUs) to offload BS traffic. We define the average amount of data transmission (AADT) to measure the network's capacity for offloading BS traffic. Based on this, we formulate a time-varying bipartite graph matching optimization problem. We decouple the problem into two subproblems which can be solved separately in terms of time and space. Then, we propose the socially aware D2MD user selection (SA-D2MD-S) algorithm based on finite horizon optimal stopping theory, and propose the SA-D2MD user matching (SA-D2MD-M) algorithm to solve the two subproblems. The results of simulations show that our algorithms outperform prevalent algorithms.

• The Journal of Fisheries Business Administration
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• v.36 no.3 s.69
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• pp.119-139
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• 2005

The purpose of this paper is to provide information that will help both fishing industry and fisheries authority understand the principals of individual transferable quota(ITQ) fishery management. Theoretical frameworks and primary features of ITQ fishery managemenet are the assignment of exclusive property rights for harvest of common - property fisheries resources. An ITQ fishery management is fundamentally different from the conventional fishery management and it gives an individual fisherman the right to catch a specified quantity of fish, his quota. With ITQ, fisherman's quotas are transferable, in whole or in part. An ITQ is a property with certain rights of use, namely, the right to catch a given quantity and species of fish in a specific location during a specific period of time. The right is exclusive in the sense that no one else has the right to use the quota without the owner's permission. The property may be assigned, traded, and exchanged; i.e., the owner has the right to transfer an ownership to others. An ITQ fishery management leads to both economic efficiency and resource conservation. Motivations to overexploit stocks and to overcapitalize should be lessened because fishermen no longer have to compete for limited resources. There are significant positive net benefits and advantages with ITQ fishery management than without. The potential benefits and advantages of ITQ fishery management include increased profits, economic stability, improved product quality, safer working conditions, less gear conflict, elimination of the race - to - fish phenomenon, less by - catch, less gear loss, improved investment climate, mitigation of market gluts, waste reduction, addition to fisherman's wealth, and compensation for fisherman exiting the fishery. As an independent observe to Red Crab Trap Fishery some of the benefits, problems, and effects, an ITQ fishery management in Red Crab Trap Fishery is still far from to be implemented. Many different and difficult aspects (biological, socioeconomics, administrative) are involved considering the implementation of ITQ fishery management in Red Crab Trap Fishery. Among other fishery management tools, the implementation of ITQ fishery management in Red Crab Trap Fishery is considered to be the best in achieving the better conservation of fisheries resources and their more economic and rational exploitation. Korean fisheries authority should pay great attention to the experience of the economic effects of the ITQ fishery management in Red Crab Trap Fishery in the hope of being able to implement at least some of those experiences into the Korean fishery management.

• Communications of Mathematical Education
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• v.20 no.3 s.27
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• pp.443-467
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• 2006

The purpose of this study was to study the 2nd grade elementary students' common thinking and differences of additive and multiplicative thinking. For meaningful discussion of the above, we have established the following research questions. 1. What are the properties of the multiplicative thinking of 2nd grade elementary students? - What are the common properties of the multiplicative thinking of 2nd grade elementary students? - What are the properties of the various multiplicative thinking levels? 2. How is multiplicative thinking presented in Korean math textbooks? The conclusions of this study were followings: First, the 2nd grade elementary students in the multiplicative thinking learnt used by translating multiplication into specific situations. And they often used different models of multiplication. Second, additive thinking developed into the multiplicative thinking. After being helped by their teachers, students who thought additively were then able to think multiplicatively. Whereas after being helped by their teachers, students who were already competent at multiplicative thinking gained a deeper understanding. Third, they learned the commutative property of multiplication after their understanding of the 'repeated addition approach' and the multiplicative approach was sufficiently reinforced. Last, students should be taught using different models based on the repeated addition approach.

• Journal of the Korean Society for Marine Environment & Energy
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• v.20 no.1
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• pp.18-25
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• 2017

Damage of both life and property has been increased by natural disaster under the influence of climate change, thus many natural disaster vulnerability researches have been carried out to make adaptation policy and impact assessment of climate change recently. Their method for assessing vulnerability usually have used proxy variables for making vulnerability indices. However, because their results were too qualitative and relative it tends to be hard to make absolute comparison and establish standard of prevention or adaptation ability. Accordingly, this study aimed at quantifying natural disaster vulnerability using emergy through recognizing disaster as the relations between order and disorder by system approach. As a result, ordering energy (4.66E+22 sej/yr) and ordered structure (1.98E+22 sej) of Busan in 2003 and disordering energy (7.80E+18 sej), disordered parts (4.55E+20 sej) and rebuilding energy (3.87E+20 sej) by typhoon Maemi were analysed. And then, this was compared with Hurricane Andrew in Dade County. Through this comparison, if the prevention ability of Busan increases, disordered parts can be reduced against the more powerful disordering energy. Also, prevention for additional damages by disaster is needed to practical rebuilding action. In conclusion, it was able to figure out the impact of disaster quantitatively by natural systems and urban systems showing as common measure. Based on this study and further research to make effective prevention for how much prevention ability should be increased will contribute to producing the scientific data for disaster management policy in future.