• Journal of Environmental Health Sciences
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• v.32 no.5 s.92
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• pp.499-505
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• 2006

Bioventing efficiency was compared in a continuous and an intermittent(6hr injection and 6hr rest) air injection mode. Two lab-scale columns which packed with 5 kg of soil artificially contaminated by diesel oil were operated. The columns were maintained at the $25^{\circ}C{\pm}2.5$ in order to minimize the effect of exterior temperature variation. The flow rate of air injection mode were maintained constantly at the flow rate of 10 ml/min. The moisture of the columns was stably maintained at $60{\sim}80%$ of field capacity. The nutrient compounds were added to make C:N:P ratio as 100:10:l. The continuous and intermittent injection modes showed 67.56% and 69.63% reduction of initial TPH concentration during 90 days, respectively. Two venting modes showed similar results in the analysis of the trends of the hydrocarbon utilizing bacterial counts for operating periods. The carbon dioxide production rate of the continuous injection mode was higher than that of intermittent injection mode. The loss of diesel oil by volatilization in the continuous and intermittent injection modes were about 5% and 1%, respectively. The lower volatilization loss in the intermittent injection mode suggested that the biodegradation of TPH in the intermittent injection mode was greater than that of the continuous mode. These results suggested that the intermittent injection mode is more efficient than the continuous venting mode.

• Journal of Environmental Health Sciences
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• v.34 no.3
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• pp.233-239
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• 2008

In order to improve reactor performance of existing sewage treatment plants, the feasibility of enhancing reactor performance by bioaugmentation using EM as bioaugmentation agent and the effects of anoxic: oxic time ratio on reactor performance were investigated. Continuous and intermittent aeration modes were compared under the 6 hr of HRT. Three different types of intermittent aeration modes, that is, 15 min, of anoxic:45 min of oxic, 30 min of anoxic: 30 min of oxic, and 45 min of anoxic: 15 min oxic respectively were chosen as test modes to study the effects of anoxic : oxic time ratios on reactor performance. The optimum anoxic: oxic time ratio was 30 min:30 min when considering simultaneous removal of organic, nitrogen and phosphorus. When applying EM into a continuously aerated reactor under the varying dosing rates of 50-200 ppm, reactor performance in terms of organic and nitrogen removal efficiencies was not improved at all. Nitrogen removal efficiency was increase when the EM dosing rate was increased. However the degree of improvement was slight when the EM was injected above 100 ppm. However optimum phosphorus removal was found at the EM dosing of 200 ppm. Thus it was found that optimum injection concentration of EM is 200 ppm. It is apparent that putting EM into a sewage treatment plant significantly affects the T-N removal efficiency of the reactor by enhancing denitrification efficiency especially in operational conditions of relatively long anoxic periods. To achieve reciprocal condition in a reactor with intermittent aeration it is necessary to enhance the reactor performance by EM injection. In the case of modifying existing continuously aerated reactors into intermittent aerated reactors, it is obvious that operating costs of aeration would be reduced by reducing aeration time when compared with existing conventional sewage treatment plants.

• Korean Journal of Ophthalmology
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• v.32 no.6
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• pp.483-487
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• 2018

Purpose: To compare the characteristics and surgical outcomes in patients with tenacious proximal fusion (TPF) and high accommodative convergence/accommodation ratio (AC/A) types of intermittent exotropia. Methods: This study retrospectively enrolled 40 patients with intermittent exotropia, 23 with TPF and 17 with high AC/A. Binocular function was evaluated by Worth's 4-dot test. Patients underwent lateral rectus recession, and surgical outcomes were compared. Surgical success was defined as less than ${\pm}10$ prism diopters (PD) at 12 months postoperatively. Results: The proportion of diplopia at near, evaluated by Worth's 4-dot test, was significantly higher in patients with high AC/A than in those with TPF (35.3% vs. 4.3%, p = 0.029). The mean preoperative angles of deviation in TPF and high AC/A types were $28.3{\pm}4.4$ and $28.8{\pm}4.5PD$ at distances, and $14.7{\pm}4.2$ and $15.1{\pm}4.1PD$ at near. Twelve months after surgery, the mean angles of deviation in TPF and high AC/A types were $2.9{\pm}9.8$ and $1.2{\pm}9.6PD$, respectively, at distance and $1.7{\pm}7.7$ and $-1.3{\pm}11.3PD$ at near. The surgical success rates were similar in the TPF and high AC/A types (74.0% vs. 64.7%). Five (21.7%) patients with TPF and 2 (11.8%) with high AC/A type experienced recurrence, with consecutive esotropia occurring in 1 (4.3%) patient with TPF and 4 (23.5%) patients with high AC/A. Conclusions: The proportion of diplopia at near was higher in patients with high AC/A type than in those with TPF intermittent exotropia. However, the surgical success rates were not significantly different between the types.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.240-245
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• 2000

This paper presents the experimental study of drilling for duralumin A2024 with intermittently decelerated feed rate. It is achieved through a programmed periodic increase and decrease in the feed rate using a machining center. The following experimental result were performed with the objective of solving chip to disposal problems. In conventional drilling of aluminum, long continuous chips are produced that wind around the drill causing difficulties in eliminating chips from the cutting zone. In order to acquire the basic data necessary to regulate the chip profile, the relationship between cutting variables and chip shape was investigated. The following conclusions are established from the experimental results. At a suitable feed fluctuation ratio, intermittently decelerated feed drilling proved successful in breaking chips to appropriate lengths while maintaining stable cutting. Thus, it is an effective method for improving chip disposal. The amplitude of the dynamic component of cutting force in intermittent feed frilling is influenced by the feed fluctuation ratio.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.1
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• pp.42-47
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• 2014

The use of BLDC motor in Vehicle and industrial field, it is operated by continuous and intermittent driving. When the intermittent driving is occurred by the rise and fall of temperature repeatedly, it was represented by different characteristics in case of continuous driving. So, it is very important that heat source estimation according to the duty ratio. In this paper, temperature characteristics according to the operating method of BLDCM was calculated by using the thermal equivalent circuit, and the validity of the study was demonstrated as compared to the calculated and experimental results.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.4
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• pp.550-555
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• 2007

The aim of this study was to determine the effect of two lighting programs (continuous lighting (CL) 24L:0D and intermittent lighting (IL) 1L:3D) on the broiler performance, carcass traits, incidence of tibial dyschondroplasia (TD), relative asymmetry (RA), duration of induced tonic immobility (TI), heterophils-lymphocytes ratio (H/L), serum glucose, cholesterol and triglyceride levels. The chicks were randomly divided into 2 treatment groups consisting of 100 chicks per treatment, continuous lighting (CL) 24L:0D or intermittent lighting (IL) 1L:3D. Each treatment consists of 5 replicates of 20 chicks. The experimental period was 6 weeks. Use of IL decreased feed to gain ratio, improved immune response and reduced fearful. Body weight, carcass traits, TD and stress parameters (organ weights, RA, H/L, glucose, cholesterol and triglyceride levels) were not significant in different lighting groups. As a result IL was beneficial for producers and chickens than CL.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.11a
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• pp.160-165
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• 2005

Bioventing efficiency was compared in a continuous and an intermittent(6hr injection and 6hr rest) air injection mode. Two lab-scale columns which packed with 5kg of soil artificially contaminated by diesel oil were operated. The columns were maintained at the $25^{\circ}C{\pm}2.5$ in order to minimize the effect of exterior temperature variation. The flow rate of air injection mode were maintained constantly at the flow rate of 10ml/min. The moisture of the columns was stably maintained at $60{\sim}80%$ of field capacity. The nutrient compounds were added to make C : N : P ratio as 100 : 10 : 1. The continuous and intermittent injection modes showed 67.56% and 69.63%reduction of initial TPH concentration during 90 days, respectively. The loss of diesel oil by volatilization in the continuous and intermittent injection modes were about 5% and 1%, respectively.

• Journal of the Korean Society of Physical Medicine
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• v.9 no.3
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• pp.307-314
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• 2014

PURPOSE: The purpose of this study was to investigate the effects of high intensity intermittent training on cardiopulmonary capacity in canoe and kayak paddlers. METHODS: A total of 16 canoe and kayak paddlers were participated in this study. Experimental group(n=8) was performed high-intensity intermittent training and control group(n=8) was moderate intensity training. All subjects performed a treadmill test in order to compare the difference before and after the intervention. Finishing the test, all subjects were measured to their heart rate(HR), forced vital capacity(FVC), forced expiratory volume in one second (FEV1) and forced expiratory ratio(FEV1/FVC). Recovery of heart rate(RHR) was calculated using the HR. HR and pulmonary flow values was measured before and during the intervention period per 2, 4, 6 and 8 weeks. To compare the differences over time between experimental group and the control group, used(time${\times}$group) two-way repeated measures ANOVA. One-way repeated ANOVA was performed to determine where differences over time within-group. RESULTS: One-way repeated ANOVA revealed a significant difference in the experimental and control group. In experimental group, %RHR3min and FEV1 were significantly increased after 4 weeks(p<.05). Also, %RHR1min, FVC and FEV1/FVC were significantly increased after 6 weeks(p<.05). In control group, %RHR1min, %RHR3min, FVC, FEV1 and FEV1/FVC were significantly increased after 6 weeks(p<.05). CONCLUSION: Not only moderate training but also high-intensity intermittent training contributes to cardiopulmonary capacity in canoe and kayak paddlers. Although high-intensity intermittent training is very short time, the training has high degree of efficiency. Therefore, developed this training in the future, it will be better to improve the cardiopulmonary capacity for athletes and healthy people.

• Child Health Nursing Research
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• v.26 no.1
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• pp.1-10
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• 2020

Purpose: This study aimed to identify psychosocial factors associated with smoking cessation attempts among Korean high school students who engage in intermittent and light smoking. Methods: Cross-sectional secondary data derived from the 2018 Korea Youth Risk Behavior Web-Based Survey were analyzed within the framework of the biopsychosocial model. The sample comprised 829 high school students who reported current intermittent and light smoking, which was defined as cigarette smoking on 1~29 days in a 30-day period and no more than 10 cigarettes per day. Purposeful selection logistic regression analysis was performed. Results: In total, 71.7% (n=586) of the respondents had tried to stop smoking during the past 12 months. The main result was that respondents who had viewed an anti-smoking advertisement in the past year significantly more smoking cessation attempts than those who had not (adjusted odds ratio=2.59; 95% confidence interval=1.45~4.62, p=.001). Conclusion: To encourage smoking cessation attempts among high school students who engage in intermittent and light smoking, healthcare providers, including school and community nurses, should develop effective interventions using anti-smoking advertisements tailored to adolescents' interests and developmental stage.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.2
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• pp.306-315
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• 2000

An experimental study was conducted to examine the internal flow patterns inside the mixing chamber of effervescent atomizers. The mixing chamber has the rectangular cross section ($8mm{\times}2mm$) and made of transparent acrylic plate for flow visualization. The parameters tested were the air/liquid ratio (ALR), injection. pressure, and the nozzle orifice diameter. Three different flow regimes were observed; bubbly, annular, and intermittent flows. In the bubbly flow regime, the discharged mixture was disintegrated into drops through the bubble expansion and the ligament breakup. On the other hand, in the annular flow regime, the liquid annulus was disintegrated into small drops by the aerodynamic interaction between the phases due to the high relative velocities between the gas and the liquid. In the intermittent flow regime, the bubble-expansion/ligament-disintegration mode and the annulus-disintegration mode appeared alternatively. The correlations representing the transition criteria between the two-phase flow patterns within the mixing chamber were proposed based on the drift-flux models.