• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.1
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• pp.55-72
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• 2018

A method that can predict the mixed-ground condition ahead of a TBM tunnel face during tunnel construction utilizing electrical resistivity and induced polarization (IP) was proposed in this study. Effect of TBM advancement approaching the mixed-ground condition (composed of soil layer overlying rock layer) when currently running through soil zone on the electrical resistivity and IP measuring was assessed with laboratory-scale experiments. The resistivity and IP values were measured using four electrodes, by installing two electrodes on the tunnel face (at the cutterhead), and the other two electrodes on the segment lining. The test results showed that both of the measured resistivity and IP values were kept increasing as the TBM is approaching the soil-rock mixed-ground. Also, to get the more reliable results for predicting the mixed-ground condition, it was recommended that the measurement is made at the tunnel face utilizing 4-electrodes installed at the cutterhead as well as it is made utilizing the 2-electrodes installed at the segment lining along with the 2-electrodes installed on the tunnel face (at the cutterhead) so that two measured results are compared each other.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.3
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• pp.417-427
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• 2000

The substrate metabolism and bacterial population in an anaerobic digestion with the submerged separation membrane were investigated by using a laboratory-scale reactor at the hydraulic retention time(HRT) 1.0 and 0.5 day. The removal efficiencies of carbohydrate at the HRT 1.0 and 0.5 day were 99.8~99.9% and 98.0~99.6%, respectively. After the 58 days, the mixed liquor volatile suspended solids(MLVSS) concentration at the HRT 1.0 and 0.5 day were approximately 6,050 and 7,750 mg/L, respectively. According to the measurement by the most probable number(MPN) method, the numbers of acidogenic bacteria, $H_2$-utilizing and acetate-utilizing methc.nogenic bacteria were found to be $10^9$, $10^7{\sim}10^8$ and $10^6{\sim}10^8MPN/mL$, respectively. The composition of $CH_4$ in the produced gas was 46~50%. It is suggested that sulfate-reducing bacteria $10^7{\sim}10^8MPN/mL$ play an important role in producing $H_2$ and acetate in sulfate-depleted environment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.1
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• pp.119-127
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• 1997

In order to investigate the distribution of the last Sea Intermediate Water (ESIW), CTD measurement was peformed in the last Sea of Korea during $8\~11$ November, 1994. ESIW was $2.0\~2.3^{\circ}C$ in potential temperature, $34.04\~34.06\%_{\circ}$ in salinity and $5.6\~6.1\;ml/l$ in of gen content on the isopycnic surface of 27.2 in potential density. The isopycnic surface of 27.2 which represented the layer of ESIW became shallower from about 200 m depth in the open sea to about 140 m depth near the coast. off the coast of Jukbyun, the 27.2 isopycnic surface was located at the depth of about 120 m and had a little higher potential temperature and salinity, lower oxygen content than those in the open sea. The ESIW on the continental shelf was higher about 0.8 ml/l in AOU, 0.02 in salinity than those of the ESIW in the open sea. These suggest that the ESIW on the continental shelf did not come from the North Korean Cold Water but originated from the open sea.

• Journal of radiological science and technology
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• v.39 no.2
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• pp.143-148
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• 2016

The purpose of this study was examined the measurement error factor on AMARES of jMRUI method for magnetic resonance spectroscopy (MRS) quantitative analysis by skilled and unskilled observer method and identified the reason of independent observers. The Point-resolved spectroscopy sequence was used to acquired magnetic resonance spectroscopy data of 10 weeks male Sprague-Dawley rat liver. The methylene protons ($(-CH_{2-})n$) of 1.3 ppm and water proton ($H_2O$) of 4.7 ppm ratio was calculated by LCModel software for using the reference data. The seven unskilled observers were calculated total lipid (methylene/water) using the jMRUI AMARES technique twice every 1 week, and we conducted interclass correlation coefficient (ICC) statistical analysis by SPSS software. The inter-observer reliability (ICC) of Cronbach's alpha value was less than 0.1. The average value of seven observer's total lipid ($0.096{\pm}0.038$) was 50% higher than LCModel reference value. The jMRUI AMARES analysis method is need to minimize the presence of the residual metabolite by identified metabolite MRS profile in order to obtain the same results as the LCModel.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.5
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• pp.539-548
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• 1995

The process of yolk absorption and the growth pattern of churn salmon, Oncorhynchus keta alevin were studied. Matured males and females of chum salmon were sampled from the Namdaechun River in the east coast of Korea, and then an artificial fertilization was carried out using their eggs and sperms. Fertilized eggs were incubated in controlled water temperature of $13^{\circ}C$ and samples of 40 alevins were randomly taken at just hatching and at every three days between 12 days alter hatching and yolk absorption. The means of total length and total weight of hatched alevins were respectively 1.97cm and 1.85g and the yolk absorption took about 33 days after hatching, based on the morphological measurement. Growth curves of total length, total weight and somatic weight were fitted well with the Gompertz growth model. However, the shrinking in yolk-sac length, yolk-sac weight, yolk-sac height and yolk-sac volume revealed a linear phenomenon until the absorption of yolk was completed. The relative growth of chum salmon alevin, such as the relationship between total length and total weight, or between total weight and yolk-sac weight, was also studied.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.1
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• pp.35-42
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• 2010

The rapid economic development induced the massive road constructions, becoming bigger and high-speed of the vehicles. However, it brings lots of social problems, such as air pollutions, traffic noise and vibration. Special concrete block for the base course of asphalt pavement is needed to decrease traffic noise such as tire's explosive and vehicles sound, applying Helmholtz Resonators theory to asphalt pavement. If it is applied to the area where it happens considerable noise such as a junction, the street of a housing complex and a residential street, it is one of considerable method to solve the social requirements of noise problem. This research examines couple of laboratory tests for the sound absorption effect of the concrete block and the base concrete block. There are specimens which is fixed hall-size, space, depth as the condition of this research, and these are analysed of noise decrease effect using different condition of the first noise of each vehicle. As a result of analysis data according to vehicle noise volume, measurement distance, a form and size of the hall using the base concrete block, the use of special concrete base showed a good alternative solution for decreasing traffic noise level, from 4 dB to 9 dB.

• Journal of agricultural medicine and community health
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• v.5 no.1
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• pp.5-15
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• 1980

The first recorded trypanosomiasis epidemic in Uganda took place at the beginning of this century in the islands and in a strip along the northern shores of Lake Victoria, which resulted in deaths of 1/3 million people. The disease was partly controlled by early 1930's and continued to occur sporadically in certain localized foci. The disease has however flared up in an explosive outbreak in Busoga district along Lake Victoria since 1977. The incidence of disease in northern district adjacent to Southern Sudan is also increasing lately. This paper describes the three month observation on the surveillance and control activities in the epidemic areas and of various health units including the Vector Control Division, the Tsetse fly Control Division, Tororo Trypanosomiasis Research Institute, medical units in Busoga, and Acholi districts. Data analysis and review were made of disease information so far collected by various health units in the Ministry of Health and district health offices. The findings may be summarized in the following: 1) A total of 12, 100 patients and 38 deaths: have occured in Busoga district since 1977 onward, and over 100 cases of diseases arc occuring in the Northern region bordering Southern Sudan. 2) the distribution of trypanosomiasis is characterized with two district patterns. The disease caused by Trypanosoma rhodesiense occurs in Busoga and is transmitted by Glossina palpalis, G. fuscipes infested in the islands and in the northern shore of forests of Lake Victoria. Another type caused by Trypanosoma gambiense occurs in Madi and Acholi in the north and is transmitted by Glossina morsitans in Savannah. 3) The house survey in Rusoga indicated that most of patients keep domestic animals in their house premises, and are engaging in either farming or fishing. Practically all the patients remembered that they had been bitten by tsetse in the field. 4) The routine diagnostic methods in the hospital laboratory is carried out through the microscopic examination of trypanosome with Giemsa stain of blood and cerebro-spinal fluid, The measurement of ESR and IgM has been used by Tororo Tryponosomiasis Research Institute for field screening.

• The Korean Journal of Malacology
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• v.27 no.3
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• pp.247-252
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• 2011

The effect of ${\gamma}$-ray irradiation on the color of nucleus and cultured pearls was investigated. After ($^{60}Co$) ${\gamma}$-ray irradiation on the pearl nucleus, its color was altered from brownish to blackish brown or gray depending on irradiation dose. It was clearly found that the all samples are composed of aragonite. ESR spectra were based on the measurement of the paramagnetic species $CO_2$-radicals by the interaction with the ${\gamma}$-ray irradiation in $Mn^{2+}$ containing $CaCO_3$. In this study, we investigated optimal detection method of ${\gamma}$-ray irradiation to establish destructive or non-destructive test for pearl nucleus.

• Journal of Digital Convergence
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• v.11 no.6
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• pp.235-244
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• 2013

This research was performed to investigate the effects of participation in aqua exercise on blood composition and vascular compliance of mentally retarded persons. The targets of this research consisted of a control group of 12 people and an aqua exercise group of 12 people after selecting 24 mentally retarded males and aqua exercise group carried out an exercise program for 60 minutes per day and five days a week for 9 weeks. Weight, body fat percentage, blood composition and vascular compliance were measured in a preliminary inspection and the same items were measured in a post-inspection. The results of this measurement were as follows. Firstly, aqua exercise group showed a significant decrease in weight and body fat percentage (p<.05). Secondly, for blood composition, aqua exercise group showed a notable decrease in Total-Cholesterol, Triglyceride, and LDL-Cholesterol (p<.05) and a significant increase in HDL-Cholesterol (p<.05). Thirdly, aqua exercise group showed a notable increase in blood composition for both upper limbs and lower limbs (p<.05). Taken these results together, it was considered that a participation of mentally retarded persons in aqua exercise would prevent adult diseases and would have an affirmative influence on improvement of the quality of life.

• Journal of Radiation Protection and Research
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• v.44 no.4
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• pp.128-148
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• 2019

Massive environmental monitoring has been conducted continuously since the Fukushima Daiichi Nuclear Power accident in March of 2011 by different monitoring methods that have different features together with migration studies of radiocesium in diverse environments. These results have clarified the characteristics of radiological environments and their temporal change around the Fukushima site. At three months after the accident, multiple radionuclides including radiostrontium and plutonium were detected in many locations; and it was confirmed that radiocesium was most important from the viewpoint of long-term exposure. Radiation levels around the Fukushima site have decreased greatly over time. The decreasing trend was found to change variously according to local conditions. The air dose rates in environments related to human living have decreased faster than expected from radioactive decay by a factor of 2-3 on average; those in pure forest have decreased more closely to physical decay. The main causes of air dose rate reduction were judged to be radioactive decay, movement of radiocesium in vertical and horizontal directions, and decontamination. Land-use categories and human activities have significantly affected the reduction tendency. Difference in the air dose rate reduction trends can be explained qualitatively according to the knowledge obtained in radiocesium migration studies; whereas, the quantitative explanation for individual sites is an important future challenge. The ecological half-lives of air dose rates have been evaluated by several researchers, and a short-term half-life within 1 year was commonly observed in the studies. An empirical model for predicting air dose rate distribution was developed based on statistical analysis of an extensive car-borne survey dataset, which enabled the prediction with confidence intervals. Different types of contamination maps were integrated to better quantify the spatial data. The obtained data were used for extended studies such as for identifying the main reactor that caused the contamination of arbitrary regions and developing standard procedures for environmental measurement and sampling. Annual external exposure doses for residents who intended to return to their homes were estimated as within a few millisieverts. Different forms of environmental data and knowledge have been provided for wide spectrum of people. Diverse aspects of lessons learned from the Fukushima accident, including practical ones, must be passed on to future generations.