• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.2
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• pp.127-137
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• 2011

We have developed a wearable device that can convert sensor data into real-time step counts and activity levels. Sensor data on gait were acquired using a triaxial accelerometer. A test was performed according to a test protocol for different walking speeds, e.g., slow walking, walking, fast walking, slow running, running, and fast running. Each test was carried out for 36 min on a treadmill with the participant wearing a portable gas analyzer (K4B2), an Actical device, and the device developed in this study. The signal vector magnitude (SVM) was used to process the X, Y, and Z values output by the triaxial accelerometer into one representative value. In addition, for accurate step-count detection, we used three algorithms: an heuristic algorithm (HA), the adaptive threshold algorithm (ATA), and the adaptive locking period algorithm (ALPA). A regression equation estimating the energy expenditure (EE) was derived by using data from the accelerometer and information on the participants. The recognition rate of our algorithm was 97.34%, and the performance of the activity conversion algorithm was better than that of the Actical device by 1.61%.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.10 no.4
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• pp.243-249
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• 2016

In this paper, we evaluate the effectiveness of mechanical horseback riding exercise training for cardiopulmonary responses in 26 healthy adults (male 14, female 12) and suggest its clinical applicability. Exercise was performed using a mechanical horseback riding machine, JOBA(R) (Panasonic Electric Works, Osaka, Japan) and riding movement speed was increased from level 2 (0.73Hz), to 4 (0.9Hz), to 6 (1.03Hz), to 8 (1.2Hz), to 9 (1.3Hz) and maintained 3minutes in each level. Heart rate, blood pressure, maximum oxygen consumption (VO2max) were measured by respiratory gas analysis system (TruOne 2400, Parvo Medics, USA) and exercise tolerance test system(Q Stress, Cardiac Science, USA). To measure exercise intensity, metabolic equivalent (MET) were measured and percent of Heart rate reserve (%HRR), percent of peak heart rate (%peak HR) and calorie consumption were calculated. The results were analysed by SPSS 18.0. We found that the exercise intensity of mechanical horseback riding exercise using JOBA(R) for 15 minutes is moderate in healthy adult who received pre-training.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.9
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• pp.911-916
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• 2006

The influence of substrate concentration and hydraulic retention time(HRT) on the hydrogen production by anaerobic microflora was investigated by conducting three series of continuous experiments the individual influences of substrate concentration and HRT. In series I, substrate concentration was increased from 3 to 27 g-glucose/L keeping HRT at 8 hr. Series II and III carried out same condition with series I at HRT of 16 hr and 24 hr, respectively. The effects of HRT and substrate concentration on the hydrogen production yield were analyzed by quadratic model. The maximum hydrogen production yield of 2.05 mol $H_2/mol$ glucose was found at the HRT of 9.6 hr and the substrate concentration of 15.4 g/L. The relationship between HRT and substrate concentration on hydrogen production yield as displayed a saddle shape in the response surface plot. Optimum HRT and substrate concentration are observed at in the range of 5 and 14 hr, at between 13 and 17 g/L, respectively, for the hydrogen production yield being 2 mol $H_2/mol$ glucose. The concentrations of organic acids increased with the increase of the amount of glucose consumption. Acetic acid and butyric acid were the main by-products from the glucose degradation.

• Journal of environmental and Sanitary engineering
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• v.5 no.2
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• pp.117-122
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• 1990

The Jido Pond system was investigated from April, 1979 through March, 1980, in respect of seasonal changes in physico-chemical factors: i.e., temperature, pH, DO, BOD, COD, $Cl^-, \; Mg^{++}$, alkalinity, detergent, $SiO_2, PO_4\;^{3-}, NH_4\;^+, NO_2\;^-, NO_3\;^-$, total N, OM and OC; phytoplankton community growth; and the ecosystem metabolism. The phytoplankton community was represented by 23 species belonging to Chlorophyta, Bacillariophyta and Cyanophyta; each sharing 11, 9 3 respectively. The Chlorophyceans dominated the phytoplankton community contributing 75% of the total ？미 counts. The ranges of biotic diversity indices were, d, 0.85~2.80; H, 1.10~2.40; c, 0.13~0/40; and 3, 0.56~0.90. The chlorophyll standing crop varied in between 0.043 and 0.385g/$\textrm{cm}^2$ surface area. The ranges of photosynthetic and respiratory rates were 0.36~4.50; and 0.10~1.40 $O_2$ mg/1/hr, respectively. The monthly areal net primary production varied from 23.9 to 305.1C g/$\textrm{m}^2$/month. The Eu of the net production seasonally varied in between 0.31 and 7.80%, and the annual mean was 2.44%. The annual turnover times of phosphorus and nitrogen were 20 and 3 days, respectively.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1978.10a
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• pp.204.2-205
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• 1978

발효유 원료유중에 항생물질이 함유되어있을 경우 이것이 발효유 제조에 미치는 영향을 검토하였다. 발효유의 원가유 살균과정, 배양기간, 보존기간중에 있어서 항생물질의 변화를 검토하기 위하여 Bacillus stearothermophilus var. calidolactis C 953을 사용한 cylinder plate법으로 penicillin의 역가를 측정하였다. 저온 장시간 $살균(60^{\circ}C,$ 30분) 조건에서는 조금도 불활성화되지 않았으나, 온도를 높이고, 시간을 길게함에 따라 점점 불활화률이 높아져 $고압멸균조건(121^{\circ}C,$ 15분)에서는 약 90% 이상이 불활화되었다. 또 현재 우리나라에서 발효유제조에 사용되고 있는 Lactobacillus casei, Hy3와 Lactoba-cillus bulgaricus Hy4A, Hy4B를 사용하여 $37^{\circ}C에서$ 배양할 경우 배양기간 중에 있어서 penicillin은 2일내에 95% 이상 불활화되었다. 그리고 $보존기간(5^{\circ}C)$ 중에는 phosphate buffer(pH 6.0)와 10% skim milk의 경우에 10일까지도 거의 불활화가 되지 않았으나, 발효유내에서는 5일만에 85% 이상이 불활화된다는 결과를 얻었다. 이와같은 발효유 배양기간과 보존기간 중의 penicillin 불활화의 원인을 규명하기 위하여 각종 유기산의 영향을 조사한 결과(조건 pH.3.30~3.45, 보존온도 $37^{\circ}C),$ 염산과 유산의 경우 24시간, 구연산의 경우 48시간, 초산의 경우 72시간내에 실험에 사용한 penicillin 농도의 99.99%가 불활화되었다. 이러한 결과로 볼 때 유산발효에서 penicillin이 불활화되는 주원인은 발효에 의하여 생성된 유기산에 의한 것으로 추정된다.방식이군이 중지방식이군과 고지방식이군에 비해 혈장내 LCAT 활성이 유의하게9p<0.001) 증가하였다. 3) 간의 콜레스테롤합성 능력은 정어리유군이 다른지방군보다(p<0.001), 무지방식이군이 식이지방첨가군보다(p<0.001), 동물성지방군의 식물성유지군보다 유의하게(p<0.001) 증가하였으나, 식이 지방의 수준에 의한 차이는 나타나지 않았다. 수용성 식이섬유소가 생리져 기능이 거의 비슷하고 무독성이 관찰됨으로써 신갈나무로부터 제조된 수용성 식이섬유소의 제조 방법이 우수하다고 볼 수 있다.있었다.세에 해당되는 중년 여성의 에너지, 단백질, 철분 섭취량을 권장량과 비교하여 보면, 각각 74.8$\pm$12.6%, 94.6$\pm$26.4% 및 64.5$\pm$14.1%로 당뇨군 (각각 112.8$\pm$28.5%, 157.8$\pm$68.2%, 92.8$\pm$21.7%)에 비해 유의하게 낮았고 정상군과는 유의한 차이를 보이지 않았다.상고나성이 있었다. 혈중 호모시스테인 농도는 질병의 위험요인으로서 뿐 아니라 대사적으로 밀접하게 연관된 비타민 영양상태의 biomarker로서도 그 영향력이 크다고 할 수 있다. 따라서 성별에 다른 다양한 연령집단에서 건강한 일반인과 심혈관계 질환자 등을 대상으로 호모시스테인과 비타민 영양상태에 대한 연구가 체계적으로 이루어 져야 할 것이다.태를 보다 효율적으로 증진시킬 수 있는 대안이 마련되어져야 한다고 사료된다.$\ulcorner$순응$\lrcorner$의 범위를 벗어나지 않는다. 그렇기 때문에도 $\ulcorner$순응$\lrcorner$과 $\ulcorner$표현$\lrcorner$의 성격과 형태를 외형상으로 더욱이 공간상에서는

• Journal of Korean Society of Environmental Engineers
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• v.22 no.11
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• pp.2097-2104
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• 2000

Naturally occurring taste and odor problems include those produced by microorganism. notably algae and bacteria. The major compounds causing taste and odor are MIB and Geosmin which can cause earthy-musty at very low concentration 9ng/L and 4ng/L, respectively. Especially, the problem is very serious from summer to fall in source and finished water. It is well known that using PAC is one of the best technology to control these compounds in drinking water treatment. In this study, optimum dosage and dosing time of PAC were observed with the adsorption isotherm experiments in single and binary compounds. Also, the effect of natural organic matter(NOM) was investigated by using a natural water with JSW. The adsorption capacity of Geosmin was higher than MIB in both with NOM and without NOM. The adsorption capacity of Geosmin and MIB was 4 times lower with NOM than that of without NOM. which was caused by competition adsorption. When the initial concentration of Geosmin and MIB were 100ng/L in JSW, at least 4 hours of reaction time was needed to achieve 99% removal with 20mg/L of the PAC.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.9
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• pp.511-516
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• 2015

On this study, we investigated the removal characteristics of residual chlorine and DBPs in tap-water during boiling. Also we investigated the releasing characteristics of essential minerals in infusion tea. While recent studies focused on removal mechanisms of harmful heavy metals in infusion tea, this study tried to suggest the way to drink tap-water healthier and safer by examining releasing mechanisms of essential minerals in infusion tea. As a result, residual chlorine(initial conc. was 0.7 mg/L) was all removed in 20 minutes after heating and DBPs (the sum of THMs, HAAs and CH) were removed up to 65%. 6 kinds of essential minerals (Ca, K, Na, Mg, S, P) were released from 5 kinds of infusion tea (barley tea, corn tea, brown rice tea, cassia seed tea, solomon's seal tea) on the market. In cassia seed tea, the amount of essential minerals released from tea showed the highest values, 9.6 mg/g, and brown rice tea was the lowest, 1.6 mg/g. Particularly, the released amounts of potassium, playing a key role in human body in maintaining normal blood pressure, cell metabolism and enzyme action, showed relatively high. Through this study, we got to know that essential minerals can be obtained up to 40% of recommended nutritional intake for Korean by boiling tap-water with infusion tea.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.11
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• pp.1161-1169
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• 2008

The removals of TCE and PCE vapor with or without a supply of toluene as a primary substrate were compared in a biofiltration process, and the variations of microbial communities associated with the removal were also investigated. As a result of investigations on the removals of TCE/PCE in a biofilter B within which TCE/PCE-acclimated sludge was attached on the surface of media without a supply of primary substrate, and those in another biofilter A where toluene-acclimated sludge was attached with a supply of toluene as a primary substrate, followings were found: (i) parts of microbes responsible to the decomposition of toluene vapor participate in the removal of chlorinated VOCs such as TCE and PCE, and (ii) effective biological removals of TCE and PCE vapor do not necessarily need cometabolism. Sequencing of 16S rDNA obtained from the band profile of DGGE (Denaturating Gradient Gel Electrophoresis), it was confirmed that: (i) uncultured alpha proteobacterium, uncultured Desulfitobacterium, uncultured Rhodobacteraceae bacterium, Cupriavidus necator, and Pseudomonas putida were found to be toluene-decomposing microbes, (ii) alpha proteobacterium HTCC396 is a TCE-removing microbe, (iii) Desulfitobacterium sp. is a PCE-decomposing microbe, and (iv) particularly, uncultured Desulfitobacterium sp. is probably a microbe decomposable not only toluene but also various chlorinated VOC vapor including TCE and PCE.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.10
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• pp.1123-1128
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• 2005

NIB(methylisoborneol) is an earthy/musty odor compound produced as a second metabolite by cyanobacteria and actinomycetes. MIB is not removed by conventional water treatment(coagulation, sedimentation, filtration) and its presence in tap water, even at low ng/L levels, can result in consumer complaints. PAC(powdered activated carbon) can effectively remove MIB when the correct dose is applied. But, since most operators in water treatment plants apply a PAC dose and then adjust that dose depending on direct observation (odor detection) after treatment, the result is often under-dose or eve,-dose. In this study, kinetic and isotherm tests using $^{14}C$-radiolabeled MIB were performed to determine coefficients for the HSDM(homogeneous surface diffusion model), including liquid film mass transfer coefficient($K_f$) and surface diffusion coefficient ($D_s$). The HSDM gave a reasonable fit and allowed prediction with the experimental data. Base on the HSDM, the authors developed an optimum PAC dose prediction program using the Excel spreadsheet. When the developed program was applied at two water treatment plants, the PAC dose based on the experience of operators in the water treatment plant was significantly different from that recommended by the newly developed program. If operators are willing to use the optimum PAC dose prediction program, it should solve dosing problems.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.7
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• pp.135-142
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• 2015

Human-powered self-generating devices have been attractive with its operation characteristic independent from outer environment such as weather condition and wind speed. However, conventional self-generators have low electric power output due to their weakly-coupled electromagnetic structure. More importantly, rotary crank motion which is usually adopted by conventional self-generator to generate electricity requires specific skeletal muscles to maintain large torque circular motion and consequently, causes fatigue on those muscles before it can generate enough amount of electricity for any practical application. Without improvement in electric power output and usability, the human-powered self-generator could not be used in everyday life. This study aims to develop a human-powered self-generator which realized a strong electromagnetic coupling in a closed-loop tubular structure (hula-hoop shape) for easy and steady long-term driving as well as larger electric output. The performance and usability of the developed human-powered generator is verified through experimental comparison with a commercial one. Additionally, human workload which is a key element of a human-powered generator but not often considered elsewhere, is estimated based on metabolic energy expenditure measured respiratory gas analyzer. Further study will focus on output and portability enhancement, which can contribute to the continuous power supply of mobile equipments.