• Journal of Institute of Control, Robotics and Systems
• /
• v.8 no.12
• /
• pp.1067-1075
• /
• 2002

The system error model for the compensation of the low-cost personal navigation system is derived and the error compensation method using GPS is also proposed. The walking navigation system (WNS) that calculates navigation information through walking detection has small error than INS, but the error also increases with time. In order to improve reliability of the system regardless of time, WNS is integrated with GPS. Since WNS is usually used in urban area, the blockage of CPS signal is frequently occurred. Therefore tightly coupled Kalman filter is used for the integration of WNS and GPS. In this paper, the system model for the design of tightly coupled Kかm filter is designed and measurement is linearized in consideration of moving distance error. It is shown by Monte Carlo simulation that the error is bounded even through the number of visible satellite is less than 4.

• The Korea Journal of Herbology
• /
• v.27 no.5
• /
• pp.15-20
• /
• 2012

Objectives : The purpose of this study was to estimate the antioxidant activity of water extract of Nelumbinis stamen (WNS) in GC-2 spd (ts) cells. Methods : we investigated the effect of WNS in mouse GC-2 spd (ts) cells by MTT assay. The protective effects of WNS against hydrogen peroxide-induced oxidative stress in GC-2 spd (ts) cells were examined by measuring cell viability. Lipid peroxidation levels and catalase were measured. Results : WNS showed cell viability as 101.9, 108.9, 111.8, 125.8, 134.5% in 2.5, 5, 10, 25, 50 ${\mu}g/ml$ concentrations, respectively. The protective effect of WNS concentration was 2.5 ${\mu}g/ml$ against hydrogen peroxide-induced oxidative stress in GC-2 spd (ts) cells. LPO were decreased significantly at 2.5, 5, 25 ${\mu}g/ml$ of WNS concentrations. Catalase activity was significantly increased at 2.5, 5 and 10 ${\mu}g/ml$ of WNS concentrations, respectively. Conclusions : In conclusion, WNS has antioxidant activities in GC-2 spd(ts) cells against oxidative stress.

• Journal of Bio-Environment Control
• /
• v.18 no.2
• /
• pp.119-123
• /
• 2009

Waste nutrient solution (WNS) that composed of nutrient solution of horticultural research institute in Japan and used for culture tomato in perlite hydroponics showed $1.9{\sim}2.4$ dS/m of EC and $5.5{\sim}7.1$ of pH. Although $NH_{4}^+$-N concentration of WNS decreased remarkably, the others did not change significantly as compared with supplied solution. The growth characteristics such as plant height, stem diameter, leaf length, and leaf width were increased as amount of compost was increased in 1 L WNS supply treatment. But there was not any regular tendency on growth characteristics in 2 L/plant WNS supply treatment. The chlorophyll content of tomato leaf was highest in I L/plant WNS supply and 4,000 kg/10a compost treatment. The fresh and dry weight, and yield of tomato fruit also increased with increase of amount of WNS and compost, and they were highest in 1 L WNS supply and 4,000 kg/10a compost treatment. The sugar content of tomato fruits was not influenced by amount of WNS and compost, fructose and glucose and total sugar was highest in 2 L/plant WNS supply and 2,000 kg/10a compost treatment. Therefore fertigation culture used WNS is environmentally friendly and can guarantee yield and quality of tomato fruits and growth of tomato plants.

• Journal of Bio-Environment Control
• /
• v.15 no.4
• /
• pp.400-405
• /
• 2006

Waste nutrient solution(WNS) using non-recycled hydroponics for melon increased contents of $NO_3$-N and cataions, such as, Ca, K, while anions except $NO_3$-N were decreased slightly as the musk melon plants grew. pH and EC of WNS were maintained 5.7$\sim$7.0, 2.0$\sim$2.2 $dS{\cdot}m^{-1}$, respectively. The musk melon plants cultivated by fertigation using WNS showed longer plant height and root length, and higher chlorophyll content than that grown by hydroponics. The fruit weight of musk melon grown by fertigation using WNS were 417.1 g heavier than that cultivated by hydroponics and soluble solids contents of musk melon fruit cultivated by fertigation using WNS was $13.3^{\circ}Brix$, that was $1.4^{\circ}Brix$ higher than that grown by hydroponics. While the growth of cucumber plants and size of cucumber fruits were not different between in fertigation using WNS and hydroponics, total yields and marketable fruit percentage showed more in fertigation using WNS than in hydroponics.

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.51 no.6
• /
• pp.221-227
• /
• 2002

In this paper, the system model for the compensation of the low-cost personal navigation system is derived and the error compensation method using GPS is also proposed. WNS(Walking Navigation System) is a kind of personal navigation system using the number of a walk, stride and azimuth. Because the accuracy of these variables determines the navigation performance, computational methods have been investigated. The step is detected using the walking patterns, stride is determined by neural network and azimuth is calculated with gyro output. The neural network filters off unnecessary motions. However, the error compensation method is needed, because the error of navigation information increases with time. In this paper, the accumulated error due to the step detection error, stride error and gyro bias is compensated by the integrating with GPS. Loosely coupled Kalman filter is used for the integration of WNS and GPS. It is shown by simulation that the error is bounded even though GPS signal is blocked.

• Journal of Bio-Environment Control
• /
• v.31 no.4
• /
• pp.460-467
• /
• 2022

The purpose of this study is to enhance utilization of the waste nutrient solution (WNS) disposed at the hydroponic greenhouse. Several sets of testing were conducted to examine the effects of WNS: (a) a fertilizer effect, (b) soil column leaching, and (c) crop cultivation. The fertilizer effect test was applied in young radish cultivation by examining the growth characteristics of young radish and soil based on inorganic nitrogen according to the soil treatment of the nitrogen fertilizer (NF) and the WNS. The fertilizer effects and crop cultivation test were conducted with five treatments (A-E): A, non-treatment (water); B, 100% of NF; C, 70% of NF + 30% of WNS; D, 50% of NF + 50% of WNS; and E, 30% of NF + 70% of WNS. The soil column leaching test was conducted with three treatments: non-treatment (water), 100% of NF, 50% of WNS + 50% of NF. As a result, the chemical properties of the WNS were pH 6.0, EC 2.4dS·m^-1, total phosphorus (T-P) 28mg·L^-1, ammonium nitrogen (NH₄-N) 5.0mg·L^-1, and nitrate nitrogen (NO₃-N) 301mg·L^-1. The chemical properties of the soil were pH 5.51, EC 0.31dS/m, organic matter 2.08g·kg^-1, NO₃-N 9.64mg·kg^-1, and NH₄-N 3.20mg·kg^-1. The results of fertilizer effects showed that the ratio of 50% or less of NF and 50% or more of WNS was high in young radish growth. There was no statistically significant difference between the soil chemistry in the C-E treatments where WNS was mixed with NF and the B treatment where only NF was applied. As a result of the soil column leaching test, there was no significant difference in the concentrations of NO₃ and NH₄ in the treatment of 100% of NF and 50% of NF + 50% of WNS. The study indicates, if the mixed fertilizer of WNS and NF is applied in the soil cultivation of young radish, it will reduce the use of NF and environmental pollution. This also helps reduce production costs on farmers and increase the yield of young radish.

• Horticultural Science & Technology
• /
• v.18 no.4
• /
• pp.518-522
• /
• 2000

The objective of this research was to determine the effect of waste nutrient solution (WNS) on growth and development of poinsettia 'Gutbier V-10 Amy'. To achieve this, WNS collected from rose grown in greenhouse was diluted with various times and 500 mL of each solution was applied every week. Then growth characteristics and nutrient uptake were determined at 180 days after transplanting. The treatment of undiluted WNS had highest plant height and length of branch among treatments tested, but there were no statistical differences in the number of bract and branches. Undiluted WNS had higher leaf number, leaf length, leaf width, fresh weight, and dry weight than any other treatments tested. There was also a trend that increased dilution times of WNS resulted in decreased plant growth. Undiluted WNS had higher chlorophyll content than Hyponex treatment, but diameter of crown did not show significant differences among treatments. In the analysis of root media collected at 6 months after fertilization, the treatment of undiluted WNS had higher electrical conductivity and organic matter content than other treatments, but the Hyponex treatment had higher phosphorus concentration than other treatments tested.

• Journal of Soil and Groundwater Environment
• /
• v.27 no.2
• /
• pp.24-35
• /
• 2022

This study was conducted to estimate groundwater demand and supply for agricultural activities in a frequent-drought area that requires implementation of optimal distribution plan utilizing the well-network system (WNS). The WNS has been considered as a viable strategic way of supplying groundwater to farmlands by connecting groundwater wells physically or virtually. The study area heavily relied on groundwater resources for irrigation up to 53% due to a lack of surface water resources. Two kinds of methods, HOMWRS software and FAO approach, were used for estimating irrigation water requirements for paddy and upland fields, respectively. During the latest 10 years (2010~2019), the water requirements was estimated to be 1,106 m³/day. The requirements notably increased to 1,121~4,004 m³/day during active farming season (May to September), which exceeded the total yield capacity of pre-existing groundwater wells (2,356 m³/day) in the area. Detailed and definite determination for groundwater demand and supply helped to determine optimal scale parameters of WNS. The WNS has achieved more balanced distribution of groundwater resources for irrigation over the study area.

• Proceedings of the KIEE Conference
• /
• 2001.07d
• /
• pp.1946-1948
• /
• 2001

본 논문에서는 저급 관성 센서를 이용한 개인 항법 장치의 모델 및 오차 보정 기법을 제시하고 성능 평가를 위하여 시뮬레이션을 수행하였다. 걸음 검출에 의한 보행 항법에서 중요한 변수인 보폭은 신경 회로망(Neural Network)을 이용하여 결정하였고, 자이로 바이어스 등에 의하여 누적되는 오차는 GPS와의 결합에 의하여 추정, 보상하였다. 이때 GPS와의 결합은 칼만필터를 이용하였으며 칼말필터를 구성하는데 필요한 오차 모델 및 결합 방법을 제시하였다. WNS/GPS 결합에 의하여 오차의 발산을 막을 수 있으며 GPS신호가 중간에 단절되는 경우에도 오차가 발산하지 않고 좋은 결과를 유지함을 보인다.

• Korean Journal of Soil Science and Fertilizer
• /
• v.44 no.3
• /
• pp.394-399
• /
• 2011

This study evaluated the effect of using waste nutrient solution (WNS) and reclaimed wastewater (WW) on the growth of Chinese cabbage and soil quality. The pH and electrical conductivity (EC) values of waste nutrient solution were 6.3 and $1.5dS\;m^{-1}$ and being 6.8 and $0.4dS\;m^{-1}$ in reclaimed WW, respectively. WNS found to be included more than $10g\;m^{-2}$ of $NO_3^-$, $K^+$, $SO_4^{2-}$ and $Ca^{2+}$, thereby enhancing Chinese cabbage growth. However, $Cl^-$ and $Na^+$ contents were higher than other nutrients in WW. Among the three irrigation resources, no significant differences were found for the growth of Chinese cabbage plants. On the other hand, pH was decreased in WNS-treated soil when compare to that in WW-treated soil which pH was increased. In spite of the uptake of nutrients by the growing plants, irrigation of the WNS led to an increase in available $P_2O_5$ and exchangeable cations such as $K^+$ and $Mg^{2+}$ in the soil when compared to soil that irrigated by groundwater or WW. Taken together, the use of WNS can remarkably reduce the amount of the chemical fertilizer for Chinese cabbage production; however, WNS can possibly cause a problem as nutrients accumulation in soil.