A laser-technology-based lifting-path tracking system for a robotic tower crane

As the number of high-rise buildings increases, so does the use of tower cranes, the number of which now tops 3000 per year in Korea. Accordingly, the safety issues of high workspaces and efficiency issues of repeated work arise in the process of lifting materials to high places. As an alternative to traditional tower cranes, we are developing a robotic tower-crane system. By developing a robotic crane system, we expect the productivity to improve by 9.9%–50% based on the results of previous studies. In this study, we examine the feasibility of a laser-technology-based lifting-path tracking system for a robotic tower-crane system. There have been efforts to develop a robotic tower crane but they could travel only through preplanned paths or had blind stop problems. We proposed a robotic tower-crane system with a laser device, an encoder, and an accelerometer, and tested the feasibility of the system under indoor, outdoor, and swinging conditions. In the process, we developed a software application to receive and record data from the laser device. The test results showed the feasibility of a proposed lifting-path tracking system for a robotic tower crane under various outdoor conditions. Several limitations have been also recognized.     

Antiobese and hypocholesterolaemic effects of an Adenophora triphylla extract in HepG2 cells and high fat diet-induced obese mice

The ethyl acetate extract from Adenophora triphylla root (ATea) had strong antioxidant effect. We hypothesised that a high fat (HF) diet might induce oxidative stress and so, dietary antioxidant may have beneficial effects on hypercholesterolaemia, but the underlying mechanisms involved are not fully understood. To test this hypothesis, C57BL/6 mice were fed with HF diet for 9 weeks. In the last 4 weeks, the HF diet was supplemented with 0, 25 or 75 mg/kg ATea. ATea decreased body weight gain and both ATea doses significantly reduced the plasma and hepatic cholesterol levels of the obese mice. Analysis of the hepatic expression of proteins known to play important roles in cholesterol metabolism indicated that ATea significantly enhanced low density lipoprotein receptor (LDL receptor) and cholesterol 7α-hydroxylase (CYP7A1) expression but inhibited the 3-hydroxy-3-methylglutaryl–CoA reductase (HMG–CoA reductase) expression in HepG2 cells and mice. No mutagenic activity was observed at high doses of ATea.     

Metrics for Quantifying the Similarities and Differences between IFC Files

Recently, several papers reported problems in data exchange using industry foundation classes (IFC). However, most comparisons were made based on a visual check, a manual count, and observation of properties that were selectively chosen. This study proposes a set of metrics for quantifying the similarities and differences between IFC files. The proposed metrics include the similarity rate, the matching rate, the globally unique identifier (GUID) preservation rate, the missing rate, and the addition rate. A long-term goal of this study is to develop a set of metrics for quantifying the information exchange rate between two IFC files. Automated identification of modified information versus newly generated information is an unsolved challenge. The proposed metrics were used in analyzing 88 IFC files generated from different systems to demonstrate the potential use of the proposed metrics.     

Antioxidant activities and contents of phytochemicals in methanolic extracts of specialty rice cultivars in Korea

Rice is an important agricultural commodity and a major staple food in Asian diets. The aims of this study were to investigate the antioxidant activities and phytochemical contents of methanolic extracts from specialty rice cultivars and to determine if there is any correlation between antioxidant activity and phytochemical content. Our results indicate that methanolic extracts from different rice cultivars contain different levels of phenolics, anthocyanin, carotenoids, γ-oryzanol, and vitamin E. Black rice cultivars such as ‘Heugkwang’, ‘Heugseol’, and ‘Heugjinju’ contained higher phytochemical contents compared to other cultivars. In contrast, the cultivars ‘Segyejinmi’, ‘Cheonseok’, ‘Hanareum’, and ‘Dasan 1’ contained significantly higher levels of γ-tocotrienol compared with other cultivars. The black rice cultivars also showed higher antioxidant activities. Phenolic content was positively correlated with DPPH and ABTS radical scavenging activities and reducing power. The results could have a direct impact on rice consumption by enhancing consumer awareness of health benefits of the rice.     

Influence of Water on the Compression Behavior of Decomposed Granite Soil

In order to investigate the influence of water on compression characteristics of decomposed granite soils, single-particle crushing and one-dimensional compression tests were carried out on three types of decomposed granite soils as well as on quartz-rich silica sand under both dry and wet conditions. Results showed that the initial crushing strength of a single particle was reduced and strength variability increased due to the weakening effects induced by the presence of water. Moreover, it was observed that the one-dimensional compression behavior of decomposed granite soil was related to the initial crushing strength. Finally, the magnitude of initial crushing strength was also affected by the degree of weathering of the soil.     

Incorporating social anxiety into a model of college problem drinking: Replication and extension.

Although research has found an association between social anxiety and alcohol use in noncollege samples, results have been mixed for college samples. College students face many novel social situations in which they may drink to reduce social anxiety. In the current study, the authors tested a model of college problem drinking, incorporating social anxiety and related psychosocial variables among 228 undergraduate volunteers. According to structural equation modeling (SEM) results, social anxiety was unrelated to alcohol use and was negatively related to drinking consequences. Perceived drinking norms mediated the social anxiety-alcohol use relation and was the variable most strongly associated with problem drinking. College students appear to be unique with respect to drinking and social anxiety. Although the notion of social anxiety alone as a risk factor for problem drinking was unsupported, additional research is necessary to determine whether there is a subset of socially anxious students who have high drinking norms and are in need of intervention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Group technology applications for computer-integrated manufacturing

Traditionally, group technology has dealt primarily with batch-type manufacturing which is engaged with small lot sizes and a variety of products. Recently, however, due to the development and implementation of computer- integrated manufacturing, group technology has been recognized as an essential element of the foundation for the successful development and implementation of computer-integrated manufacturing through the application of the part-family concept and also a common database for CAD/CAM integration. The optimum design and effective operation of a fully automated manufacturing cell system and/ or factory systems for factories of the future require a careful analysis of all the requirements which the system must satisfy under a group technology environment.     

On the Self-Generation of Electrical Soliton Pulses

The nonlinear transmission line is a structure where short-duration pulses called electrical solitons can be created and propagated. By combining, in a closed-loop topology, the nonlinear line and a special amplifier that provides not only gain but also mechanisms to tame inherently unruly soliton dynamics, we recently constructed the first electrical soliton oscillator that self-generates a stable, periodic train of electrical soliton pulses (Ricketts , IEEE Trans. MTT, 2006). This paper starts with a review of this recently introduced circuit concept, and then reports on new contributions, i.e., further experimental studies of the dynamics of the stable soliton oscillator and a CMOS prototype demonstrating the chip-scale operation of the stable soliton oscillator. Finally, we go to the opposite end of the spectrum and present a numerical study showing the possibilities that deliberate promotions of the unruly soliton dynamics in the closed-loop topology can produce chaotic signals.