• Title/Summary/Keyword: environment condition

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The Effect of Transient Eccentric Propeller Forces on Shaft Behavior Measured Using the Strain Gauge Method During Starboard Turning of a 4,700 DWT Ship (스트레인 게이지법을 이용한 4,700 DWT 선박의 우현 전타시 프로펠러 편심추력이 축 거동에 미치는 영향 연구)

  • Lee, Jae-ung;Kim, Hong-Ryeol;Rim, Geung-Su
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.24 no.4
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    • pp.482-488
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    • 2018
  • Generally, after stern tube bearing shows a significant increase in local load due to propeller load, which increases the potential adverse effects of bearing failure. To prevent this, research on regarding shaft alignment has been carried out with a focus on reducing the relative slope between the shaft and support bearing(s) under quasi-static conditions. However, for a more detailed evaluation of a shafting system, it is necessary to consider dynamic conditions. In this context, the results revealed that eccentric propeller force under transient conditions such as a rapid rudder turn at NCR, lead to fluid-induced instability and imbalanced vibration in the stern tube. In addition, compared with NCR condition, it has been confirmed that eccentric propeller forces given a rapid rudder starboard turn can lift a shaft from the stern tube bearing in the stern tube, contributes to load relief for the stern tube bearing.

Antioxidant activity and phenolic acid content of Gynostemma pentaphyllum leaves according to extraction conditions

  • Ko, Hyun Min;Eom, Tae Kil;Kim, Ju-Sung
    • Korean Journal of Agricultural Science
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    • v.46 no.1
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    • pp.85-92
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    • 2019
  • This study was intended to provide basic data for a health functional food study by exploring antioxidant activity of reflux extract according to the concentration of ethanol and the extract of ultrasonic waves extracted and reflux extracted under the same solvent conditions. In the same solvent condition, the reflux extract ($75.10{\pm}1.99mg$) showed a higher total phenol content than the ultrasonic wave extract ($51.74{\pm}2.28mg$). Flavonoids also had a higher reflux extract ($25.05{\pm}1.53mg$) than did ultrasonic extracts ($16.23{\pm}1.95mg$). Reflux extract according to ethanol concentration was found to have a higher phenol content than the 70% ethanol extract ($40.60{\pm}1.49mg$) in 60% ethanol extract. Flavonoid content was also similar to phenol content in reflux extract as determined by ethanol concentration from 60% ethanol ($25.05{\pm}1.53mg$) to 70% ethanol extract ($6.60{\pm}0.46mg$). In addition, the antioxidant activity (DPPH, TEAC, FRAP, ORAC) of the reflux extract in the same solvent conditions tended to be higher than that of ultrasonic extracts. Also, 60% ethanol extract had better antioxidant activity than 70% ethanol extract. However, an analysis of phenolic acid content through HPLC showed that the ultrasonic extract had a higher content in the same solvent condition than did the reflux extract. Not only the presence of phenolic acid, but also those of other compounds are believed to be attributed to the activity of antioxidants. Therefore, further studies are needed to clarify this phenomenon.

Determination of Hydrophyte Index of Native Plant on the Downstream Slope of Earth Fill Dam (필댐 하류사면 자생식물의 습생지수 결정)

  • Kim, Hyun Soo;Ryu, Bum Hee;Park, Seung Ki
    • Journal of The Korean Society of Agricultural Engineers
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    • v.61 no.1
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    • pp.131-144
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    • 2019
  • The purpose of study was to determine the hygrophyte index of each plant(HIP) considering the moisture environment condition (MEC) of the native plants on the downstream slope of the fill dam and evaluate its applicability which to develop a method to search for leaks and saturated zones of the fill dam for status evaluation of precision safety diagnosis. The HIP was weighted average and consisted of 19 ranks. The weighted average was calculated according to the following three procedures: First, the linear assumption was made according to the actual habitat environmental conditions, the second one was weighted to 10% of the optimal habitat condition, and finally the average value of the distribution range values. The Hygrophyte index of vegetation at each plot (HIV) was obtained from the Sinheung reservoir (Yesan-gun, Chungcheongnam-do) using the results of vegetation survey of the Sinheung reservoir with precision safety diagnosis and suggested the use of the hygrophyte index of the cultivated vegetation. The average HIP range of plant species that emerged in 50 survey sites on the downstream slope of the Sinheung reservoir is 2.99 to 3.56. The coefficient of variation showed a large difference depending on the appearance of the leakage indicator plant(LIP) species. The range of HIV is 2.80 to 4.26, the mean value is 3.37, standard deviation is 0.37 and the coefficient of variation is 9.7%. As a result, the value of the coefficient of variation showed a large difference depending on the appearance of the plant species.

Estimation of Discharge Load due to Combined Sewer Overflows in the Management of Total Maximum Daily Loads (수질오염총량관리 관거월류부하 변화에 따른 배출부하량 산정방법)

  • Park, Jun Dae;Oh, Seung Young;Choi, Ok Youn
    • Journal of Korean Society on Water Environment
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    • v.27 no.3
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    • pp.293-299
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    • 2011
  • The quantity of a discharge load can change with changes in rainfall in the area with a combined sewer system (CSS). To evaluate the implementation appropriately in the management of total maximum daily loads (TMDLs), the effects of rainfall changes should be considered in the estimation of the discharge load. The rainfall condition for the estimation of the discharge load in a certain year should be standardized to the same rainfall condition as that of the reference year. However, the calculation process is very complicated with its potential limitations. This study investigated and developed relatively simple methods for estimating the discharge load. Load conversion method (LCM) is designed to convert the discharge load under the current rainfall condition into that of the reference rainfall conditions. Simple rainfall data method (SRDM) is to simplify the estimation process of the discharge load by the simple conversion of rainfall data. These methods were applied to calculate the discharge load and examine the estimation results. From the results of this study the application of these methods may be useful for estimating the discharge load in the TMDL process.

Research for the Selection of Agricultural environment in Papua New Guinea (파푸아뉴기니 농업 환경 기초조사)

  • Chang, Kwang Jin;Koo, Hyun Jung;Choi, Jang-Nam
    • Journal of Practical Agriculture & Fisheries Research
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    • v.17 no.1
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    • pp.183-204
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    • 2015
  • Papua New Guinea, birthplace of the South Pacific, is a natural nation which have potential of increasing crops output because it has optimum condition for crop growth as tropical rain forest climate under hot and humid climate. Farming village of Papua New Guinea want to produce crops for create income beyond the self-sufficiency. It needs the technological transfer such as irrigation facilities and understanding of agricultural weather condition for good crops production. In particular, it needs a improvement through pH, EC, ORP for make optimum soil condition and it need the standardization production and farm products what the consumer wants. Internationally technical cooperation is needed for agricultural development of Papua New Guinea and maintenance of international cooperation will help for economic development between the two countries. In particular, basic environment research for agricultural development of Papua New Guinea is expected to play a larger role of technical cooperation of agriculture.

Analysis on the Inequality Indicator of the Housing Condition Distribution (주거복지 분배 불평등 지수 연구)

  • Lee, Kang-Hee;Chae, Chang-U
    • KIEAE Journal
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    • v.17 no.2
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    • pp.45-51
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    • 2017
  • Purpose: Housing is the most essential element for well-being in a society. The government would continuously supply decent housings to make a better living condition for people. As various housing policies have been implemented into practice, the effectiveness of policies need to be assessed and improved to rearrange the financial resources. The indicators, such as quality of life, housing supply amount and etc, could be used to estimate housing policy to provide a guidance for a new policy direction. Though various indicators are utilized to assess the policy effect, most of the items are depend upon a relativeness in aspect to assessment goal, items, time and its weighting. Therefore, it needs an absolute indicator to compare the policy effectiveness regardless of time elapse or items. In this paper, it developed the housing welfare indicator to assess the level of living condition, utilizing the Gini coefficient which is used for explanation on income distribution. Method: To suggest an inequity indicator, this paper used Gini coefficient to explain the level of living condition which is used on economics to provide the level of income distribution. Data are collected through the Korea Housing Survey by Ministry of Land, Infrastructure and Transport between 2006 and 2014. Indicators of living condition focused on the development of the estimation model using the frequency of room use. Result: Gini coefficient between 2004 and 2014 is about 1.5 score except in year 2013, and the trend of score has been decreased slowly which means the inequality gradually improved. In this result, it implies the living condition and distribution level would be improved than before.

Difference of Proprioceptive Sense at Elbow Joint According to Measurement Methods (팔굽관절에서 측정방법에 따른 고유수용성감각 차이)

  • Lee, Jung-Ah;Kim, Duk-Hwa;Shin, Hwa-Kyung;Choi, Kyu-Hwan;Kwon, Oh-Yun
    • Physical Therapy Korea
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    • v.10 no.3
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    • pp.63-70
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    • 2003
  • The purpose of this study was to compare the difference of joint position sense between measurements. Fourteen healthy male subjects were recruited for this study. The elbow joint position senses were measured using angle reproduction test. The elbow joint position sense was assessed with three experimental conditions: ipsilateral reproduction test in open-chain condition, contralateral reproduction test in open-chain condition, ipsilateral reproduction test with weight in open-chain condition and ipsilateral reproduction test in closed-chain condition. The angular difference between stimulus position and the reproduced position (angular error) was calculated in all testing conditions to examine the accuracy of the joint position sense. One way ANOVA was used to compare the error angles in all experimental conditions. The error angles between measurements were significantly different in elbow joint. The error angles was smallest in ipsilateral reproduction test with weight in open-chain condition and was greatest in the contralateral reproduction test in open-chain condition. Findings of this study indicate that testing methods, types of task, existence of resistance should be considered in clinical assessment for the joint position sense.

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Small Punch Test of TRIP Steel Charged with Hydrogen under Different Electrolyte Condition (다른 전해질분위기에서 수소주입시킨 TRIP강의 SP시험)

  • Kim, Kwang-Sig;Yoo, Kwang-Hyun;Park, Jae-Woo;Kang, Kae-Myung
    • Journal of the Korean Institute of Gas
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    • v.19 no.1
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    • pp.64-70
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    • 2015
  • In order to evaluate the degree of hydrogen embrittlement of TRIP steels charged with hydrogen according to varying the current density and the charging time under acid and alkaline electrolyte conditions were tested by small punch test. The results of SP test showed that the degree of hydrogen embrittlement at acid electrolyte condition was more effective factor compared to that of alkaline electrolyte condition. Therefore, all of the charging time and the charging current density were at the condition of acid electrolyte appeared as the main factor of the degree of hydrogen embrittlement in the condition of acid electrolyte. But, it was considered that the charging time compared to the charging current density at the condition of alkaline electrolyte was more effective factor to raise the degree of hydrogen embrittlement.

Scheduling Technique for Remodeling Project of Inhabited Condition (재실 리모델링 특성을 반영한 공정계획 기법)

  • Paik, Hwa-Sook;Nam, Wook-Jin;Kim, Sung-Han;Kim, Hyung-Jin;Choi, Jong-Soo;Kim, Kyung-Hwan
    • Korean Journal of Construction Engineering and Management
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    • v.14 no.2
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    • pp.141-149
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    • 2013
  • This paper presents a scheduling technique that reflects various constraints in remodeling project of inhabited condition. The remodeling project of inhabited condition is required more detailed planning and control due to claims by noise, vibration, dust, smells, limited lift capacity, and limited temporary stock area. Because of the constraints, complexity in scheduling is increased and earlier completion is required to reduce the possibility of safety and environment accidents. Especially, in case of inhabited condition, the scheduling should be linked day-time/night-time/weekend work. This paper proposes a structured scheduling technique to incorporate those constraints in remodeling of inhabited condition. This scheduling technique considers not only remodeling process but also dismantling, newly-construction, and residents movement. Process expression method using MS-Project also presented to keep connectivity with existing scheduling system.

Location Information Reliability-Based Precision Locating System Using NLOS Condition Estimation (NLOS 상태 추정을 이용한 위치 정보 신뢰성 기반의 정밀 위치 측정 시스템)

  • Son, Sanghyun;Choi, Hoon;Cho, Hyuntae;Baek, Yunju
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38C no.1
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    • pp.97-108
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    • 2013
  • Recently, mobile devices were increased and there was a sharp rise in demand. To exploit the location information of each device, many researcher was studying locating systems. The favorite locating or positioning systems were a GPS using satellites and a RTLS using wireless communication between devices. If some obstacle existed nearby the target device, The system have difference of performance. The obstacles near targets were caused signal disconnection and reflection because of NLOS condition. As the result, the NLOS condition degrade the locating performance. In this paper, we propose a locating system which is cooperated two systems using information reliability estimates from LOS/NLOS condition. We developed proposed system. In addition, we performed fields test and simulation tests at various environment for performance evaluation. As the result, the test showed 97% success rate to estimate NLOS condition. Furthermore, the simulation result of our locating system was increased to 89% compared with a single system.