• Journal of The Korean Society of Agricultural Engineers
• /
• v.48 no.3
• /
• pp.35-45
• /
• 2006

Fallow paddy areas have been increased due to the import of cheap agricultural product, and the unbalance between farming cost and rice price since 1990. In domestic, rice production control that decrease paddy field area has been introduced for the control of rice demand and supply and stabilization of rice price since 2003. Because of the desire of paddy field's owner to create benefit by using paddy for other object, fallow paddy would be continuously increased. In the other aspect, many people in the world is suffering from hunger because of the shortage of food. In case of Korea, continuous drought and flood damages will be potential concern of stable food supply. From this viewpoint, the increasing fallow paddy area needs to be protected from the devastation by weed breeding for the re-cultivation. In this study, fallow paddy managed with the shallow pools and shallows was selected fur monitoring and analyzing of water quality and plant body change. As the results, the managed fallow paddy found to be effective in the purification of water quality and the control of plant growth.

• Journal of Fashion Business
• /
• v.8 no.3
• /
• pp.59-69
• /
• 2004

This thesis has an intention to examine how much Bobos, which has appeared as a new ruling class in the age of digital information economy, has had an influence on the fashion design and which aspect Bobos fashion assumes specifically. The existence of Bobos in Korea and its cultural disposition are examined. To do so, questionnaire survey has been performed for 400 persons. According to the result, it is shown that they control themselves thoroughly through exercise and have much interest in their health; for example, they prefer organic agricultural products and nonpolluting foods. They also consume goods reasonably, emphasizing on their own individuality, rather than purchase high-price articles for no good reason, and enjoy their life while seeking for success in the society. Such a disposition is almost same as that in the U.S, showing a small difference in the occupation or origins. It is examined which aspect Bobos fashion design, a new trend, assumes in more detail. Bobos seeks for a thing that is not cheap, has a recognized brand, and is not behind the fashion. They like the nature friendly, classical, and not vulgar thing. design should be casual and practical, and the quality of the material should be good. Especially, an individual disposition is emphasized in Bobos fashion, in which they disregard a brand and try to be the subject of a trend, by creating a fashion by themselves, to express their originality freely. Bobos fashion the first style it harmonizes the appear things not to be matching with each other and depending on pursuing the mix & match. The second style of Bobos fashion nature is friendship and fight. The hazard which it does like that the fact that it attempts is the composition characteristic of idea. The namely design is an utility cheap assuredly with high-class characteristic of subject matter is not a recognize cheap. The third style of Bobos fashion is expressed in nostalgic about the art. Of course Bobos style is not a possibility fashion as main stream of doing still today, but the effect of Bobos is magnified gradually from cultural, social, economic area. It analyzes style is a tendency where trend of the consumer is gradually converted marketing. This paper is meaningful in the sense that Bobos class, which has not been examined yet systematically, and the fashion are connected closely, and the fashion trend in the next is examined.

• Management & Information Systems Review
• /
• v.1
• /
• pp.333-362
• /
• 1997

Since the profess of the reformation and opening Policy in 1978, China has been outstandingly developed its economy and increased the real scale of its economy 4 times as big as before, and is expected to rise as a superpower holding in check U.S.A even in economy as well as politics, military affairs and diplomacy in the 21st century. In this position, China has constantly tried to join WTO since 1986, as an effort to gain a status in the international society. It hsa been making various economic reformations to provoke a crustal movement in its own economy such as tariffs lowering measurement for the almost whole items, remove of restriction of import items, lowering the refunding rate of over deposit tax and annihilation of the special treatments for the foreign investment. In short, recently Chinese government is cutting down the special treatments for the foreign capital enterprises and changing the policy to the direction of gradually reinforcing the control, so it requires that our enterprises trying to advance and invest in China have to consider these carefully. Investment in China of our enterprises become serious since 1990 is focused on such labor intensive industries as textiles, sewing and shoes which lost the competitive power due to the wage increase. Particularly, Pusan economy having played the role of locomotive for Korean economy in the past developing period has been weakened in the competitiveness and not yet activated in 1990s. In terms of this, the enterprises engaged in such typical industries of Pusan as shoes, textiles and sewing have borne much fruit from the investment in China with abundant and cheap labors. However, from a few years the enterprises in Pusan invested in China due to the cheap labors and rich resources and invested in China have suffered much troubles and failures more and more resulted from the advancement without sufficient previous knowledge and information related to the investment including investment environment. Therefore, at the time of advancement in China, Korean enterprises should make their decision related to the investment, after taking these investment environment into account previously to a full extent and making an investment strategy.

• The Journal of Korea Robotics Society
• /
• v.12 no.3
• /
• pp.350-355
• /
• 2017

UWB (Ultra Wide Band) refers to a system with a bandwidth of over 500 MHz or a bandwidth of 20% of the center frequency. It is robust against channel fading and has a wide signal bandwidth. Using the IR-UWB based ranging system, it is possible to obtain decimeter-level ranging accuracy. Furthermore, IR-UWB system enables acquisition over glass or cement with high resolution. In recent years, IR-UWB-based ranging chipsets have become cheap and popular, and it has become possible to implement positioning systems of several tens of centimeters. The system can be configured as one-way ranging (OWR) positioning system for fast ranging and TWR (two-way ranging) positioning system for cheap and robust ranging. On the other hand, the ranging based positioning system has a limitation on the number of terminals for localization because it takes time to perform a communication procedure to perform ranging. To overcome this problem, code multiplexing and channel multiplexing are performed. However, errors occur in measurement due to interference between channels and code, multipath, and so on. The measurement filtering is used to reduce the measurement error, but more fundamentally, techniques for removing these measurements should be studied. First, the TWR based positioning was analyzed from a stochastic point of view and the effects of outlier measurements were summarized. The positioning algorithm for analytically identifying and removing single outlier is summarized and extended to three dimensions. Through the simulation, we have verified the algorithm to detect and remove single outliers.

• Journal of Power System Engineering
• /
• v.20 no.6
• /
• pp.27-33
• /
• 2016

BLDC motors have the strong point of allowing high-efficiency operation, yet with the weak point of requiring position information for operation. Moreover, there have recently been frequent cases where the product differentiation of even a cheap BLDC motor demanded a high level of control performance similar to that of a controller using a high-precision position sensor. This paper proposes low cost position sensor that enables the acquisition of rotor position information based on index and incremental PWM, using a single position sensor instead of an expensive incremental encoder or a cheap 3 phase hall sensor. The characteristic of the proposed encoder is that index information at every $60^{\circ}$ of electrical angle is inscribed on the encoder disk, as well as a multiple number of values representing information about PWM, which is obtained by modulating information about the electrical angle of the rotor that has the resolution of $60^{\circ}$. Such a method has the characteristic of enabling the acquisition of high-precision position information based on the information about a multiple number of PWM waveforms and counter values that have all been inscribed on the encoder disk for each $60^{\circ}$ range. The feasibility of the proposed new encoder was verified by fabricating a prototype encoder generating 240 pulses, followed by confirming its performance using Micom's capture and software counter functions.

• Safety and Health at Work
• /
• v.11 no.2
• /
• pp.143-151
• /
• 2020

Objective: Bidi is an inexpensive, low-processed, hand-rolled tobacco product. In Bangladesh, especially in Rangpur, tobacco farming and bidi processing are common. In this study, we aimed to evaluate the impact of bidi making on children working in bidi factories. Methods: This qualitative(walk-through survey) and quantitative(questionnaire-based survey and a urine cotinine level quantitation) study was conducted in Rangpur, Bangladesh in 2017. Study population included child-workers aged ≤14 years who were regularly employed as bidi makers. Findings: The results of the walk-through survey revealed hazardous working environments at bidi factories. For the quantitative survey, 171 child-workers were categorized into "less-working"(<5 hours/day) and "more-working"(≥5 hours/day) groups; additionally, "forced-working"(forced into work by parents) and "voluntary-working"(working voluntarily) groups were delineated within the same population. In the logistic regression analysis, odds ratios(ORs) of respiratory symptoms and unusual absence(absent ≥5 days/month) were higher in the "more-working" group than in the "less-working" group(unusual absence: OR, 2.91; 95% confidence interval[CI], 1.43-5.94), and this association became higher in the "forced-working" group with longer working hours(OR, 5.68, 95%CI 2.30-14.00). Conclusions: Cheap, hand-rolled tobacco(bidi) is harmful to the health of bidi-making child-workers. Children in poverty bow to the demands of cheap labor and poverty and jeopardize their health and future prospects by working in bidi factories. Tobacco control policies should consider the social effects of tobacco beyond its biological effects.

• Korean Journal of Medicinal Crop Science
• /
• v.10 no.4
• /
• pp.237-242
• /
• 2002

It was found that the purified extract from A. gigas Nakai (polysaccharide, M.W., 25 kD) controled differentiating human ES cells. Its optimal supplementation concentration was decided as 0.8 $({\mu}g/ml)$ to efficiently control the differentiation. It also enhanced the cell growth, compared to the control. However, most widely used and commercially available differentiating agent, Leukemia Inhibitory Factor (LIF) negatively affected on the cell growth even though it controls the differentiation of ES cells, down to 40-50 % based on morphological observation and telomerase activity. It was presumed that the extract first affected on cell membrane and resulted in controlling signal system, then amplify gene expression of telomere, which enhanced the telomerase activity up to three times compared to the control. LIF only increased the enzyme activity up to two times. It was confirmed that the extract from A. gigas Nakai could be used for substituting currently used differentiation controlling agent, LIF from animal resources as a cheap plant resource and not affecting the cell growth. It can broaden the application of the plants not only to functional foods and their substitutes but also to fine chemicals and most cutting-edge biopharmaceutical medicine.

• Journal of Institute of Control, Robotics and Systems
• /
• v.5 no.6
• /
• pp.753-763
• /
• 1999

The existing SCADA(Supervisory Control and Data Acquisition) system software is usually developed to suitable for the specific hardware platforms. However, as per rapid improvement of computer performance and development of network technology, it is required to support scalability and inter-operability in existing different SCADA systems. In order to meet such requirements, in this paper, we propose a new type of SCADA testbed using Java for electric distribution applications. The system consists of three modules; development support tools, client and server modules. The basic architecture of the proposed SCADA system is similar to existing one, however, we improve the function of MTU and MMI interface to facilitate LAN and WAN environment. Also, the proposed system can deals with alarm and history data by using heterogeneous DBMS. Since the system is built in Java environment, the development cost is cheap and it can support sacalability and portability. Our experience can be utilized to develop next generation of small and medium size of SCADA system.

• 한국정보통신설비학회:학술대회논문집
• /
• 2006.08a
• /
• pp.57-61
• /
• 2006

As high speed internet users are tremendously increasing, three are keenly in need of development of high speed portable internet technology which can provide high quality wireless internet service cheaply even in the mobile. Unlike the FDD-CDMA, TDD-OFDMA has relatively poor wave environment with inducing interference, fading and delay because it agrees to multi-carrier modulation method and time-division radio telecommunication system. To solve this problem, it is necessary to develop repeater operating by digital signal processing method which have more strict wireless channel control and wave signal processing technology over TDD telecommunication equipments. This thesis is dealing with design and implementation of Digital RF Repeater which implemented 'Synchronization Acquisition Unit', 'TDD signal switching Unit', 'Feedback Signal Cancellation Unit'. Over this argument, we will develop digital RF repeater with more cheap, more adaptive in wave environment like oscillation control, adaptive wave monitoring and output increasing and having control function as a result it will be helpful for success in high speed portable internet service business.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.19 no.6
• /
• pp.511-521
• /
• 2014

This study proposes an electric vehicle (EV) smart panel board and its control method on the basis of charging scheduling. The proposed system consists of batteries, a three-phase battery charger, three single-phase inverters, transfer switches for electric power distribution, and a controller. The three-phase battery charger usually charges the batteries at midnight when electric rates are cheap and in light load. When the electric power consumption of the EV standard chargers connected to one phase of the power line is relatively large or when a blackout occurs, the electric power stored in the battery is supplied by discharging through the inverters to the EV standard chargers. As a result, the value of peak load and the charging electric power quantity supplied from a utility grid are reduced, and the current unbalance is improved. The usefulness of the proposed system is confirmed through simulations, experiments, and case studies.