• 대한한의학회지
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• 제29권1호
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• pp.117-133
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• 2008

Objectives : Since ancient times, Koreans have applied medicinal spabaths for treatment of various diseases. The objective of this study was to investigate the effect of strontium, one of the common ingredients of such baths, experimentally on acute skin barrier damage. Materials and Methods : Male hairless mice, average weight 20g, were divided into six groups. Each group consisted of five mice. The first was the normal, non-treated group. The second was the control group with acute skin barrier damage intentionally induced by TS. The third was the Ba-Sr1 group bathed in 1mg/L strontium chloride before and after inducing acute skin barrier damage by TS. The fourth was the Ba-Sr7 group bathed in 7mg/L strontium chloride before and after inducing acute skin barrier damage by TS. The fifth was the Sr1 group bathed in 1mg/L of strontium chloride only after intentionally inducing acute skin barrier damage by TS. The sixth was the Sr7 group bathed in 7mg/L of strontium chloride only after intentionally inducing acute skin barrier damage by TS. External changes of skin, skin erythema level, transepidermal water loss level, and GOT and GPT level of each group were checked immediately before and after TS, 3 hrs, 5 hrs and 24 hrs after inducing acute skin barrier damage. Then, tissue samples were made and examined for damage to epithelial cells, stratum corneum, change of mucous polysaccharide in dermis and amount of mast cells. Statistical analysis was performed by one way-ANOVA, Scheffe and Duncan for a post hoc test and pairwise comparison for comparing for difference between each time. Statistical significance was achieved if the probability was less than 5% (p<0.05) Results : 1. From skin erythema and TEWL level indicating the function of the skin barrier, we can know that it is helpful to the skin barrier to bathe in a water solution including a low concentration of strontium. 2. In the control group with acute skin barrier damage induced by TS, skin barrier damage persisted until 3-5 hrs and recovered after 5-24 hrs. Differently from the control group, in the case of taking a bath in a water solution including strontium, skin barrier damage recovered after only 3-5 hrs. Therefore, the bath with a water solution including strontium can promote recovery of the skin barrier. 3. Bathing in water solution including a higher concentration of strontium was more beneficial to recovery of skin barrier damage. 4. There was no influence on serum GOT and GPT from bathing in a water solution including strontium. Conclusions : The strontium was effective for recovery and mitigation of acute skin barrier damage induced by tape stripping. I suggest that strontium (Sr) can be used as an external treatment medicine, addedinto bath water to treat acute skin barrier damage.

• 환경영향평가
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• 제16권2호
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• pp.143-156
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• 2007

This study has researched the management status and the pollution level of water, soil, stream sediments of 11 abandoned coal mines out of a total of 12 within Obong-Dam area except Bukyung mine, which was submerged when constructing Obong-Dam, and selected areas which are in needs to have pollution control facilities in the first place. From the results of examination on the runoff at the waste rock pile and mineheads, the runoff from Sueun mine (pH, Fe, Al), Samwon mine (pH, Al), Wangdo mine (pH, Al), Mose mine (pH, Fe, Al) and Daeryeong mine (pH) exceeded the permissible discharge standards of the water quality, but the water at merging point with Obong-Dam after joined with Doma branch satisfied both Water Quality Standards and Drinking Water Quality Standards. In regard to groundwater contamination, it is found that areas where exceeded the Drinking Water Quality Standards are Wangdo mine (pH), Jangjae mine (pH, Zn), Daeryeong mine (pH) whereas all areas satisfied Soil Contamination Warning Standards of Soil Environmental Conservation Law. When comparing a research result on underwater sediments of branches of abandoned mines to the EPA Guidelines for classification of great lakes harbor sediments, Dongguk Gaerim (Fe), Jungwon mine (Fe), Daebo mine (Mn), Samwon mine (Mn) and Daeryeong mine (Mn) showed mid-level of contamination, whereas Sueun (Fe, Mn), Daebo mine (Fe), Woosung mine (Fe, Mn), Wangdo mine (Fe, Mn), Mose mine (Fe) and Daeryeong mine (Fe) showed high-level of contamination. In addition, contamination levels of underwater sediments in Wangsan and Doma branch where abandoned mine's branches merge together, Wangsan branch showed no contamination at all whereas Doma branch shows mid-level of contamination which reflect the Doma branch is affected by waste rock pile and minehead runoff of the abandoned mines in the Doma branch area. It is concluded that Mose mine and Sueun mine required treatment of acid mine drainage. and Wangdo, Jungwon, and Samwon mines were in need of mine tailing and erosion control work. The Samwon mine additionally required a control system for closed minehead runoff. Although the Samwon mine reached a high concentration of Al, Mn $Ca^{2+}$, $SO{_4}^{2-}$ in the runoff, the levels decreased after it was combined with a tributary. It has been concluded that after further monitoring of the cause of pollution, a preventive measure system may be needed to be built.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2019년도 학술발표회
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• pp.43-47
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• 2019

본 연구에서는 수리모형실험을 통해 사이펀 여수로에 장착된 air slot의 방류량 조절 능력을 검토하였다. air slot의 단면 형상으로 원호 및 직사각형 형상을 채택하였으며, 개구부 면적을 조절할 수 있게 하였다. air slot이 장착된 경우 사이펀 관 내부에 공기와 물이 혼합된 복잡한 흐름이 발생하였다. air slot이 장착된 사이펀 여수로에서 저수지 내측 수위가 상승할 때와 하강할 때 동일한 수위에서 동일한 유량이 계측되었다. air slot의 무차원 개구부 면적이 증가할수록 무차원 방류량은 더 서서히 증가하였다. 수리모형실험 결과는 air slot의 면적 조절을 통해 사이펀을 통한 방류량 조절이 가능함을 보여주었다.

• 한국해안·해양공학회논문집
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• 제22권3호
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• pp.181-190
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• 2010

실 해역에 잠제를 건설할 경우, 잠제 전면과 배후의 평균수위차로 인하여 잠제의 단부를 중심으로 순환류가 발생하게 된다. 이에 본 연구에서는 잠제 주변의 평균수위를 조절하여 주변 흐름을 제어할 수 있는 신형식 잠제를 제안하여 그 기능을 검토하는 것을 목적으로 한다. 먼저 3차원 수치모델, LES-WASS-3D를 수리모형실험결과와 비교 검토하여 수치모델의 타당성을 검증한 후, 이 모델을 이용하여 신형식 잠제에 대한 수치시뮬레이션을 수행하였다. 수치계산결과를 근거로 신형식 잠제 주변의 흐름제어기능에 대해 논의함과 동시에 신형식 잠제 주변의 평균수위분포, 파고분포, 평균류분포에 대해 고찰하였다. 결과로서 본 연구에서 제안한 신형식 잠제는 잠제 배후의 평균수위를 낮추어서 개구부의 이안류를 줄이는 것을 확인할 수 있었다.

• 전력전자학회논문지
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• 제18권6호
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• pp.530-539
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• 2013

In large vessels, proper water level must be maintained with a balance for right and left equilibrium by absorbing or draining sea water in ballast water tank. However, this ship's ballast-water can be drained marine organisms to local sea area by world trade and this can be a source of ecological disturb. In order to solve these problems, marine organisms must be removed in accordance with the international covenant for the emission of microorganisms. By this reason, the seawater electrolysis rectifier of low-voltage high-current rectifiers with excellent ability for microbial treatment is required. In this paper, PSFB converter will be discussed for the seawater electrolysis rectifier. Furthermore, a new output control method with the power limit operation under the limited maximum voltage condition is proposed for this rectifier. The simulation for the proposed current control method for PSFB Converter is shown using MATLAB/SIMULINK. Finally the usefulness of the proposed control method is presented by the experimental results.

• 산업기술연구
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• 제20권A호
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• pp.257-267
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• 2000

It was difficult to apply conventional excavation methods in some sections from Seoul to Pusan high speed rail road construction of 1 lot 2, due to highway concrete road, gas pipe, water pipe and nearby factories with automatic control system machine. To excavate safely and efficiently in these sections new blast patterns were employed within allowable blast vibration level, by test blast and controlled vibration by sequential blast. Behaviors of the rock mass including convergence and displacement around tunnel were measured with construction works and the crack width in concrete wall was also monitored for controlling allowable limits. The results can be summarized as follow : 1. The allowable blast vibration level in structure site is less 1.0cm/sec for highway concrete, 0.5 cm/sec for gas pipe, water pipe and building housing and 0.3 cm/sec for automatic control system machine. 2. The convergence displacement, single rod extensometer and multi rod extensometer around tunnel and cracks in concrete wall were measured, it was confirmed that the measured values were converged within allowable level. 3. The empirical formular of ground vibrations with 90% confidence lines for PD-3 was given as follow. $$V_{90%}=45.549({\frac{D}{\sqrt{W}}})^{-1.353}$$

• 대한한방내과학회지
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• 제19권1호
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• pp.114-133
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• 1998

In order to investigate the effects of Alcohol-Steamed Rhei Rhizoma and Row Rhei Rhizoma on varied extract time in both endotoxin-induced blood stasis model(hereafter Endotoxin Model) and hydrocortisone acetate-induced blood stasis model (hereafter HA Model), Half of rats were treated with endotoxin(0.4mg/kg, single Ⅳ, into caudal vein) for Endotoxin Model. Thereafter, they were orally administrated water extract of Alcohol-Steamed Rhei Rhizoma or Row Rhei Rhizoma, which were boiled during 30, 60, 120 minute, respectively. Finally, the number of platelet, fibrinogen, prothrombin time, hematocrit, the number of RBC and WBC were measured after sacrifice. The remainder rats were treated with hydrocortisone acetate(10mg/kg, daily IM for 7 days into the muscular rump) for HA significantly decreased. Together, they were orally administrated for 7 days water extract of Alcohol-Steamed Rhei Rhizoma or Row Rhei Rhizoma that were boiled above methods Finally, the number of platelet, fibrinogen, prothrombin time, hematocrit, the number of RBC and WBC were measured after sacrifice. The results were summarized as follows : 1. The number of platelet was significantly increased in boiled water extract for 30 min of Row Rhei Rhizoma group as compared with that of control group in Endotoxin Model. 2. Fibrinogen level was significantly increased in all administration groups as compared with that of control group in Endotoxin Model. It was significantly increased in all administration groups except boiled water extract for 30 min of Alcohol-Steamed Rhei Rhizoma group as compared with that of control group in HA Model. 3. Prothrombin time was significantly shortened in boiled water extract for 60 min of Alcohol-Steamed Rhei Rhizoma group and boiled water extract for 120 min of Alcohol-Steamed Rhei Rhizoma group as compared with that of control group in Endotoxin Model It was significantly shortened all administration groups as compared with that of control group in HA Model. 4 Hematocrit was significantly increased in all administered groups except boiled water extract for 60 min of Alcohol-Steamed Rhei Rhizoma group and boiled water extract for 30 min of Row Rhei Rhizoma group as compared with that of control group in Endotoxin Model. It was significantly increased in all administration groups as compared with that of control group in HA Model. 5. The number of RBC was significantly decreased in boiled water extract for 60 min of Alcohol-Steamed Rhei Rhizoma group, boiled water extract for 120 min of Alcohol -Steamed Rhei Rhizoma group and boiled water extract for 30 min of Row Rhei Rhizoma administered group in Endotoxin Model. It was significantly increased boiled water extract for 30 min of Row Rhei Rhizoma group and boiled water extract for 60 min of Row Rhei Rhizoma group in HA Model as compared with data of control group. 6 The number of WBC was significantly decreased in all administered groups except boiled water extract for 30 min of Alcohol-Steamed Rhei Rhizoma group and boiled water extract for 60 min of Alcohol-Steamed Rhei Rhizoma group as compared with that of control group in HA Model.

• 생물환경조절학회지
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• 제30권4호
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• pp.367-376
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• 2021

우리나라 딸기 재배는 시설 재배로 이루어지고 있으며, 대부분 농가의 급액 관리는 재배자의 경험을 토대로 타이머 제어 방식으로 이루어지고 있다. 타이머 급액 방법은 재배 환경, 작물의 생육 단계, 배지 수분 함량 등을 고려하기 어려워 작물을 최적 수준으로 관리하지 못하고, 급액 관리의 정확성이 결여되는 문제점이 있다. 적산 일사량과 배지 수분함량을 이용한 급액 방법은 작물의 생육 상태에 따라 정밀하게 양액을 공급하는 친환경적인 방법이다. 본 연구는 코이어배지를 이용한 딸기 수경재배에서 적산일사량과 배지 수분함량을 이용한 복합 급액 제어와 타이머 제어 급액 방법을 비교하고 복합 급액 제어 시 최적의 적산 일사량 기준을 설정하고자 수행하였다. 적산일사량 급액 방법은 외부 일사량을 기준으로 100, 150, 250J·cm^-2에 도달하면 자동으로 급액하며 배지 수분함량이 60% 미만이면 강제 급액하고, 1회 급액량은 50mL로 공급하였다. 타이머 제어는 대조구로 설정하였다. 급액을 개시하는 적산 일사량 기준이 작을수록 일일급액량이 많았으며 100J·cm^-2 기준 급액 시 급액량은 250J·cm^-2 처리구 대비 46% 많았다. 지상부 생체중과 건물중 모두 복합 급액 제어 방법이 타이머 제어보다 높았으며, 100, 150J·cm^-2 처리구에서 지상부 생체중이 높았고 100J·cm^-2 처리구에서 건물중이 유의하게 높은 값을 나타냈다. 수량 또한 타이머 제어 방법보다 복합 제어 방법에서 유의하게 높았으며 적산 일사량 기준이 작을수록 초기 수량이 증가하였다. 평균 과중은 타이머 제어 급액 시 가장 낮았다. 본 연구 결과 딸기의 정밀 급액 관리를 위하여 적산 일사량과 배지 수분 함량 센서를 이용한 복합 제어 활용 가능성을 확인하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 D
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• pp.2192-2195
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• 2002

Even though, tanks are used at the many industry plants, it is very difficult to control the tank level without any overflow and shortage; moreover, cause of its complication of dynamics and nonlinearity, it's impossible to realize the accurate control using the mathematical model which can be applied to the various operation modes. However, the sliding mode controller(SMC) is known as having the robust variable structures for the nonlinear control systems with the parametric perturbations and with the sudden disturbances. It's difficult to find SMC's parameters, and SMC is bring chattering which injures actuator and increases error. In this paper, Genetic Aloglism based Fuzzy Sliding Mode Controller(GA-FSMC) for the precise control of the coupled tank level was proposed. Genetic Algolism and Fuzzy logic are adapted to find SMC's parameters and reduce the chattering. The simulation result is shown that the tank level could be satisfactorily controlled with less overshoot and steady-state error by the proposed GA-FSMC.

• 센서학회지
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• 제27권2호
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• pp.86-92
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• 2018

In recent times, motion capture technology using inertial measurement unit (IMU) sensors has been actively used in sports. In this study, we developed a canoe paddle, installed with an IMU and a water level sensor, as a system tool for training and calibration purposes in water sports. The hardware was fabricated to control an attitude heading reference system (AHRS) module, a water level sensor, a communication module, and a wireless charging circuit. We also developed an application program for the mobile device that processes paddling motion data from the paddling operation and also visualizes it. An AHRS module with acceleration, gyro, and geomagnetic sensors each having three axes, and a resistive water level sensor that senses the immersion depth in the water of the paddle represented the paddle motion. The motion data transmitted from the paddle device is internally decoded and classified by the application program in the mobile device to perform visualization and to operate functions of the mobile training/correction system. To conclude, we tried to provide mobile knowledge service through paddle sport data using this technique. The developed system works reasonably well to be used as a basic training and posture correction tool for paddle sports; the transmission delay time of the sensor system is measured within 90 ms, and it shows that there is no complication in its practical usage.