Royal jelly (RJ) is one of the most attractive functional foods that have been a commercial product, especially in dietetics and cosmetics in many countries. However, RJ has been evoked with dermatitis, acute asthma and anaphylaxis because of major RJ proteins. Therefore, to access water soluble royal jelly (WSRJ) that removed allergy-induced proteins as an effective whitening agent for cosmetics and potential external treatment for topical use, we investigated its ability to inhibit melanin biosynthesis. B16F1 cells were treated with 10 nM α-melanocyte-stimulating hormone (α -MSH) for 48hr, and then were treated with various doses of WSRJ for 36hr. WSRJ (1-10ug/ml) inhibited direct tyrosinase activity and cellular tyrosinase activity, which lead to the decrease of melanin synthesis in α-MSH stimulated B16F1 melanoma cells. In addition, we examined RT-PCR and Western blotting for melanogenesis-related genes such as tyrosinase, tyrosinase related protein 1 (TRP-1) and 2. WSRJ suppressed mRNA and protein expression of tyrosinase, tyrosinase related protein (TRP)-1 and TRP-2 in α-MSH stimulated B16F1 cells, and similar to positive control, arbutin. Our findings suggest that WSRJ induced the downregulation of melanogenesis by inhibiting tyrosinase, TRP-1 and 2 activations. It may serve as a new candidate in the new skin-whitening agents.

This paper presents a sensitivity optimization of a MEMS (microelectromechanical systems) gyroscope for a magnet-gyro system. The magnet-gyro system, which is a guidance system for a AGV (automatic or automated guided vehicle), uses a magnet positioning system and a yaw gyroscope. The magnet positioning system measures magnetism of a cylindrical magnet embedded on the floor, and AGV is guided by the motion direction angle calculated with the measured magnetism. If the magnet positioning system does not measure the magnetism, the AGV is guided by using angular velocity measured with the gyroscope. The gyroscope used for the magnet-gyro system is usually MEMS type. Because the MEMS gyroscope is made from the process technology in semiconductor device fabrication, it has small size, low-power and low price. However, the MEMS gyroscope has drift phenomenon caused by noise and calculation error. Precision ADC (analog to digital converter) and accurate sensitivity are needed to minimize the drift phenomenon. Therefore, this paper proposes the method of the sensitivity optimization of the MEMS gyroscope using DEAS (dynamic encoding algorithm for searches). For experiment, we used the AGV mounted with a laser navigation system which is able to measure accurate position of the AGV and compared result by the sensitivity value calculated by the proposed method with result by the sensitivity in specification of the MEMS gyroscope. In experimental results, we verified that the sensitivity value through the proposed method can calculate more accurate motion direction angle of the AGV.

This paper presents a study of path-planning method for AGV(automated guided vehicle) based on path-tracking. It is important to find an optimized path among the AGV techniques. This is due to the fact that the AGV is conditioned to follow the predetermined path. Consequently, the path-planning method is implemented directly affects the whole AGV operation in terms of its performance efficiency. In many existing methods are used optimization algorithms to find optimized path. However, such methods are often prone with problems in handling the issue of inefficiency that exists in system's operation due to inherent undue time delay created by heavy load of complex computation. To solve such problems, we offer path-planning method using modified binary tree. For the purpose of our experiment, we initially designed a AGV that is equiped with laser navigation, two encoders, a gyro sensor that is meant to be operated within actual environment with given set of constrictions and layout for the AGV testing. The result of our study reflects the fact that within such environments, the proposed method showed improvement in its efficiency in finding optimized path.

This paper presents to study the path tracking method of AGV(autonomous guided vehicle) which has a laser guidance system. An existing automatic guided vehicles(AGVs) which were able to drive on wired line only had a automatic guidance system. However, the automatic guidance systems that those used had the high cost of installation and maintenance, and the difficulty of system change according to variation of working environment. To solve such problems, we make the laser guidance system which is consisted of a laser navigation and gyro, encoder. That is robust against noise, and flexible according to working environment through sensor fusion. The laser guidance system can do a perfect autonomous driving. However, the commercialization of perfect autonomous driving system is difficult, because the perfect autonomous driving system must recognize the whole environment of working space. Hence, this paper studied the path tracking of AGV using laser guidance system without wired line. The path tracking method is consisted of virtual path generation method and driving control method. To experiment, we use the fork-type AGV which is made by ourselves, and do a path tracking experiments repeatedly on same experimental environment. In result, we verified that proposed system is efficient and stable for actual fork-type AGV.