• International Commerce and Information Review
• /
• v.15 no.4
• /
• pp.267-286
• /
• 2013

The WCO Time Release Study (TRS) is a unique tool and method for measuring the actual performance of Customs activities. The ultimate aim of TRS is to improve the performance of the function being measured. To be more specific, TRS is used for identifying bottlenecks in the international supply chain and/or constraints affecting Customs release, assessing newly introduced and modified techniques, procedures, technologies and infrastructure, or administrative changes, establishing baseline trade facilitation performance measurement, identifying opportunities for trade facilitation improvements and estimating the country's approximate comparative position as a benchmark tool. The effective utilization methods of TRS for trade facilitation in Korea Customs Services are as follows ; Firstly, it is necessary to make every efforts to identify bottlenecks in border-related procedures and improve their procedures for continuous and more improved trade facilitation. Secondly, it is necessary to optimize and simplify export-related procedures using the TRS in exportation for efficiency of total international supply chain. Thirdly, it is necessary to make coordinated border management with main trading partners. Lastly, it is necessary to enhance Korea's international status to support underdeveloped countries in the field of trade procedures.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.50 no.11
• /
• pp.12-20
• /
• 2013

Even though extensive research results have been applied to wireless cellular systems to improve their capacity and coverage, severe performance degradation experienced in cell boundary areas still remains as a major limiting factor to prohibit further improvement of user equipment (UE) throughput. In the Long Term Evolution-Advanced (LTE-A) standard of the Third Generation Partnership Project (3GPP), Some advanced techniques have been introduced to overcome this "cell-edge problem", including coordinated multipoint transmission and reception (CoMP) and inter-cell interference coordination (ICIC). In this paper, we propose yet another strategy to improve the performance of low-tier UEs by using the concept of multiple beam direction patterns (BDPs). Such multiple BDPs can be implemented using multi-layer antenna arrays stacked vertically at base station (BS) sites to transmit signals in different main beam directions. In comparison to conventional three-sector antennas with a fixed beam pattern, the proposed methods makes signal transmission in a rotational fashion to significantly enhance the reception quality of UEs located near sector (or cell) edge areas, preventing the situation where certain UEs are marginally covered by the BS for the whole transmission time. Performance evaluation results show that the proposed scheme outperforms the conventional three-sector transmission by 171% in low 5% UEs in terms of the UE throughput.

• The Journal of Bigdata
• /
• v.5 no.1
• /
• pp.155-180
• /
• 2020

It takes the most important role the problem of assigining vehicles and desigining optimal routes for each vehicle in order to enhance the logistics service level. While solving the problem, various cost factors such as number of vehicles, the capacity of vehicles, total travelling distance, should be considered at the same time. Although most of logistics service providers introduced the Transportation Management System (TMS), the system has the limitation which can not consider the practical constraints. In order to make the solution of TMS applicable, it is required experts revised the solution of TMS based on their own experience and intuition. In this research, different from previous research which have focused on minimizing the total cost, it has been proposed the methodology which can enhance the efficiency and fairness of asset utilization, simultaneously. First of all, it has been adopted the Cluster-First Route-Second (CFRS) approach. Based on the location of customers, we have grouped customers as clusters by using four different clustering algorithm such as K-Means, K-Medoids, DBSCAN, Model-based clustering and a procedural approach, Fisher & Jaikumar algorithm. After getting the result of clustering, it has been developed the optiamal vehicle routes within clusters. Based on the result of numerical experiments, it can be said that the propsed approach based on CFRS may guarantee the better performance in terms of total travelling time and distance. At the same time, the variance of travelling distance and number of visiting customers among vehicles, it can be concluded that the proposed approach can guarantee the better performance of assigning tasks in terms of fairness.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.48 no.5
• /
• pp.74-82
• /
• 2011

SSD has a limitation of number of erase/write cycles and does not allow in-place update unlike the hard disk because SSD is composed of an array of NAND flash memory. Thus, FTL is used to effectively manage SSD of having different characteristics from traditional disk. FTL has page, block, log-block mapping method. Among then, when log-block mapping method such as BAST and FAST is used, the performance of SSD is degraded because frequent merge operations cause lots of pages to be copied and deleted. This paper proposes a data allocation and replacement method based on access frequency by allocating PRAM as checking area of access frequency, log blocks, storing region of hot data in SSD. The proposed method can enhance the performance and lifetime of SSD by storing cold data to flash memory and storing log blocks and frequently accessed data to PRAM and then reducing merge and erase operations. Besides, a data replacement method is used to increase utilization of PRAM which has limitation of capacity. The experimental results show that the ratio of erase operations of the proposed method is 46%, 38% smaller than those of BAST and FAST and the write performance of the proposed method is 34%, 19% higher than those of BAST and FAST, and the read performance of the proposed method is 5%, 3% higher than those of BAST and FAST, respectively.

• Korea journal of population studies
• /
• v.20 no.2
• /
• pp.135-159
• /
• 1997

Education effect on women's participation in the labor market has been known to be small in Korea. Then, the meaning of women's education as human capital needs to be questioned. Both the increasing desire for working among women and the criticism to under-utilization of women's education in the labor market reflect that women's education is surely perceived as human capital. However, women's education dose not seem to function well as human capital in the labor market. According to previous studies, it is pointed out that educational effect on women's participation in the labor market is weak but the effect on earnings is evident. There were few attempts to evaluate economic returns to women's education over the life-cycle analyzing both working and non-working women. Considering that the economic behaviors of women in nonagricultural sector have changed little until the mid-1980s, I tried to examine the meaning of education as human capital over the women's life cycle using cross - sectional data. This study shows that the educational effect on women's participation in the labor market does not exist and the working period is very short. Although the educational effect on earnings among working women is clearly shown, it tends to limited to younger women. Despite the educational effect on earnings among younger women, the meaning of education as human capital among Korean women does not hold well due to short working period and the low participation of the educated in the labor market.

• Journal of the Korea Society of Computer and Information
• /
• v.17 no.12
• /
• pp.31-39
• /
• 2012

In this paper, we propose a microprocessor-based automatic voltage regulator(AVR) to reduce consumers' electric energy consumption and to help controlling peak demanding power. Hybrid Switching Automatic Voltage Regulator (HS-AVR) consist of a toroidal core, several tap control switches, display and command control parts. The coil forms an autotransformer which has a serial main winding and four parallel auxiliary windings. It controls the output voltage by changing the combination of the coils and the switches. Relays are adopted as the link switches of the coils to minimize the loss. To make connecting and disconnecting time accurate, relays of the circuit have parallel TRIACs. A software phase locked loop(PLL) has been used to synchronize the timings of the switches to the voltage waveform. The software PLL informs the input voltage zero-crossing and positive/negative peak timing. The traditional voltage transformers and AVRs have a disadvantage of having a large mandatory capacity to accommodate maximum inrush current to avoid the switch contact damage. But we propose a suitable AVR for every purpose in smart grid with reduced size and increased efficiency.

• Korean Journal of Plant Resources
• /
• v.25 no.1
• /
• pp.80-88
• /
• 2012

This study was conducted to clarify the antimicrobial effects and radical scavenging activities of the cosmetic compositions having the natural plant pigments, and to enhance the natural materials utilization of cosmetics. The antimicrobial activities of the fifteen kinds of cosmetic composition having natural plant pigments were evaluated using the agar diffusion method. Most of the cosmetic composition having the natural pigments showed the clear zone formation of growth inhibition against Bacillus subtilis, Staphylococcus aureus, Listeria monocytogenes, Vibrio parahaemolyticus and Aspergillus flavus. Especially, purple sweet potato, bitter melon, mulberry leaf and gromwell showed the higher antimicrobial activities. All the cosmetic compositions were evaluated for their antioxidant activity using DPPH radical scavenging capacity and nitrite scavenging ability activity. Both of the free radical DPPH and nitrite scavenging ability was the highest in the cosmetic compositions of onion peel, and these antioxidant activity was significant differences according to different plant pigments. In this study, we conjectured that the plant pigment had the potent biological activities, therefore these plant resources having functional components could be a good materials for development into source of natural cosmetics.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.14 no.2
• /
• pp.79-89
• /
• 2012

This study was conducted to investigate the chlorophyll contents, photosynthetic characteristics, chlorophyll fluorescence, and growth performance of Parasenecio firmus under changing light environment. Parasenecio firmus was grown under non-treated (full sunlight) and three different shading conditions (88~93%, 65~75% and 45%~55% of full sunlight) for the experiment. Total chlorophyll content, photochemical efficiency (Fv/Fm), T/R ratio, specific leaf area (SLA), leaf area ratio (LAR), and leaf weight ratio (LWR) were increased with increasing shading level, but decreased dark respiration. Therefore, light absorption and light utilization efficiency were improved under the low intensity light. Plants under 65~75% of full sunlight had best maximum photosynthetic rate and net apparent quantum yield in May. On the other hand, the non-treated plants had lower maximum photosynthetic rate, photochemical efficiency, and chlorophyll content than the treated ones. Parasenecio firmus considered to be a sciophyte, is fairly sensitive to high intensity light. If 88-93% of full sunlight lasts for a long period, photosynthetic capacity will be sharply decreased, though limiting light. These results suggest that growth of Parasenecio firmus adapted to 65~75% of full sunlight.

• Journal of Korea Water Resources Association
• /
• v.41 no.10
• /
• pp.983-993
• /
• 2008

In recent times, sea level increasing caused by abnormal weather and global warming, sea-sand dredging and complex development causes various kind of erosion damages onto the coastal area in the world. The various types of erosion control and protection methods are applied but there are no signs of fruitful effectiveness. The PC concrete protection block for shore protection structure is practically installed in globally but most of structures in the present day became villainous because of bad accessability. In this study, hydrophilic revetments for control and protection of coastline erosion will be developed in order to make up for a faculty of the shore erosion protection block with better accessibility and excellent protection ability. Experimental measurements were researched to insure for the capacity and facility on reflection coefficient, overtopping volume, and overtopping height characteristics of newly developed shore erosion protection block in model tests. As the result, hydraulic model tests show much excellent than the general step block. Field tests were carried out also to verify through vegetative test on an affinity and construction work test of control-protection on coastline erosion with actual utilization. In the latter case, deposition of sand accumulation occurred in fairly short time at the established reaches and then we can be confirmed to utilize for newly developed block as the revetments for control and protection of coastline erosion.

• Journal of Korean Society of Transportation
• /
• v.27 no.5
• /
• pp.97-111
• /
• 2009

Image-based traffic information collection systems have entered widespread adoption and use in many countries since these systems are not only capable of replacing existing loop-based detectors which have limitations in management and administration, but are also capable of providing and managing a wide variety of traffic related information. In addition, these systems are expanding rapidly in terms of purpose and scope of use. Currently, the utilization of image processing technology in the field of traffic accident management is limited to installing surveillance cameras on locations where traffic accidents are expected to occur and digitalizing of recorded data. Accurately recording the sequence of situations around a traffic accident in a signal intersection and then objectively and clearly analyzing how such accident occurred is more urgent and important than anything else in resolving a traffic accident. Therefore, in this research, we intend to present a technology capable of overcoming problems in which advanced existing technologies exhibited limitations in handling real-time due to large data capacity such as object separation of vehicles and tracking, which pose difficulties due to environmental diversities and changes at a signal intersection with complex traffic situations, as pointed out by many past researches while presenting and implementing an active and environmentally adaptive methodology capable of effectively reducing false detection situations which frequently occur even with the Gaussian complex model analytical method which has been considered the best among well-known environmental obstacle reduction methods. To prove that the technology developed by this research has performance advantage over existing automatic traffic accident recording systems, a test was performed by entering image data from an actually operating crossroad online in real-time. The test results were compared with the performance of other existing technologies.