• 대한치과의사협회지
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• 제49권4호
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• pp.219-226
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• 2011

Snoring and obstructive sleep apnea (OSA) are common sleep disordered breathing conditions. Habitual snoring is caused by a vibration of soft tissue of upper airway while breath in sleeping, and obstructive sleep apnea is caused by the repeated obstructions of airflow for a sleeping, specially airflow of pharynx. Researchers have shown that snoring is the most important symptom connected with the obstructive sleep apnea syndrome The treatment is directed toward improving the air flow by various surgical and nonsurgical methods. The current surgical procedures used are uvulopalatopharyngoplasty(UPPP), orthognathic surgery, nasal cavity surgery. Among the nonsurgical methods there are nasal continuous positive air pressure(CPAP), pharmacologic therapy. weight loss in obese patient, oral appliance(sleep splint). Sleep splint brings the mandible forward in order to increase upper airway volume and prevents total upper airway collapse during sleep. However, the precise mechanism of action is not yet completely understood, especially aerodynamic factor. The aim of this study evaluated the effect of conservative treatment of snoring and OSAS by sleep splint through measured aerodynamic change by an aerophone II. We measured a airflow, sound pressure level, duration, mean power from overall airflow by aerophone II mask. The results indicated that on a positive correlation between a decrease in maximum airflow rate and a decrease in maximum sound pressure level, on a negative correlation between a decrease in maximum airflow rate and a increase in duration.

• Environmental Analysis Health and Toxicology
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• 제6권1_2호
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• pp.39-57
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• 1991

The effect of red ginseng ethanol extract on the immunotoxicity of diethylstilbestrol (DES) was studied in ICR mice. ICR male mice were divided into S groups (10 mice/group), and red ginseng ethanol extract (50, 100 and 200 mg/kg body wt., respectively) and DES (1 mg/kg body wt.) were injected intraperitoneally (i.p.) to ICR mice once a day for 2 weeks. Mice were sensitized and challenged with sheep red blood cells (S-RBC). Immune response were evaluated by humoral immunity, cell-mediated immunity, non-specific immunity, and circulating leukocyte counts. The results of this study were summarized as followings: 1. The DES-treated control group as compared with normal group showed the tendency to decrease body weight rate and relative liver weight, decreased both humoral and cellular immune responses, phagocyte activity, and circulating leukocyte counts, but increased the natural killer (NK) cell activity. 2. Compared with the DES-treated control group, DES plus red ginseng ethanol extract-treated groups significantly decreased the body weight rate (P<0.01). Relative liver weight was significantly decreased in DES plus red ginseng ethanol extract (50mg/kg)-treated group (P<0.01), but significantly increased in DES plus red ginseng ethanol extract (100mg/kg)-treated group (P<0.01). Relative spleen and thymus weights were significantly enhanced in DES plus red ginseng ethanol extract (100 mg/kg)-treated group (P<0.01), but significantly decreased in DES plus red ginseng ethanol extract (200 mg/kg)-treated group (P<0.01). 3. Both humoral and cellular immune responses were significantly decreased in DES plus red ginseng ethanol extract-treated groups rather than in the DES-treated control group (P<0.01). Especially, it weakened the decrease in DES plus red ginseng ethanol extract (100 mg/kg)-treated group. 4. Phagocyte activity and circulating leukocyte counts were significantly decreased in DES plus red ginseng ethanol extract-treated groups rather than in the DES-treated control group (P<0.01). Especially, it weakened the decrease in DES plus red ginseng ethanol extract (100 mg/kg)-treated group. NK cell activity was significantly enhanced in DES plus red ginseng ethanol extract (100 mg/kg)-treated group (P<0.01), but significantly decreased in DES plus red ginseng ethanol extract (50 and 200 mg/kg)-treated groups (P<0.01).

• The Korean Journal of Physiology
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• 제22권2호
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• pp.319-332
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• 1988

The regulations of renal function and renin release are influenced by neural, humoral and physical factors. During the last decade, considerable progress has been made in the identification and characterization of these extrinsic renal control systems. Mechanisms intrinsic to the kidney are also important for renal function. These include the autoregulation of blood flow, and the local control of renin secretion. Fundamental questions regarding the mechanism of these intrinsic controls remain unanswered. Recently, endogenous renal adenosine has been claimed to influence the tubuloglomerular feedback control and renin release. Two subclasses of adenosine receptors $A_1{\;}and{\;}A_2$ have been described. The present experiment was carried out to evaluate the effects of $N_6-cyclohexyladenosine$ $(CHA,{\;}A_1{\;}selective)$ and 5'-N-ethylcarbox-amide adenosine $(NECA,{\;}A_2{\;}selective)$ on the renal function and renin release in the unanesthetized rabbit. Intra-renal arterial infusion of NECA $(0.3{\sim}10.0n{\;}mole/min/rabbit)$ or CHA $(0.03{\sim}10.0n{\;}mole/min/rabbit)$ caused a prompt and dose-dependent decrease in urine volume, glomerular filtration rate (GFR), renal plasma flow (RPF), filtration fraction (FF), electrolyte excretion and free water clearance $(CH_2O)$, the effect being much more profound with CHA than with NECA. The NECA infusion resulted in a profound decrease of systemic blood pressure, but the CHA infusion did not. Both NECA and GHA infusions caused a prompt and dose-dependent decrease in renin secretion rate, again the effect being greater with CHA than with NEGA. These results suggest that both $A_1{\;}and{\;}A_2$ adenosine receptors may be involved in the intrinsic control of renal function and renin release, and that the $A_1$ receptors plays a more important role than the $A_2$ receptor in the regulation of renal fnction.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집B
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• pp.371-376
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• 2000

In this study, the computational method is presented to simulate the hemodynamics of the patients after the Fontan procedure. The short-term feedback control models are implemented to assess the hemodynamic responses of the patients exposed to the stresses such as gravitational effect or hemorrhage. To construct the base line of the Fontan model, we assume an increase in venous tone, in heart rates, and in systemic resistance that are based on the clinical observations. For the verification of the present method we simulate the LBNP (lower body negative pressure) test for the normal and the Fontan model and we compare these with experimental data. Computational results show that the diastolic ABP(arterial blood pressure) increases but the systolic ABP decreases during LBNP. The increase in heart rate is due to the control system activated by the decreased mean ABP and CVP(central venous pressure). In case of the Fontan model, the increased venous tone is the reason of the diminished CVP change during LBNP. We also simulate 20% hemorrhage stress to the patient after the Fontan procedure and these results are compared with the experimental and the existing computational one. Computational results on the hemodynamics of patients after the Fontan procedure show that the mean ABP and cardiac output decrease. Heart rate and systemic resistance increase to compensate for the decrease in ABP. The sensitivity analysis according to the conduit resistance is also presented to delineate the effects of the local blood flow resistance. The cardiac output decreases according to the increase of the conduit resistance. The 50% increase in the conduit resistance causes about 3% decrease of cardiac output.

• 대한기계학회논문집
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• 제10권1호
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• pp.86-95
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• 1986

본 연구에서는 폭이 일정한 급경사 개수노상(0.15mW*1.6mL)을 상온의 물이 유동할 때 유동율과 수로 급경사에 따른 명입치에서의 유동깊이 변화를 실측을 통하여 밝히고 이념치와 비교하였다.

• 농촌계획
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• 제21권4호
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• pp.85-94
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• 2015

The purpose of this study is to investigate how the hollowization in rural villages which causes marginal villages appears in Korean rural villages and whether the hollowization has relation with decrease and aging of population or not. For achieving the research objective, survey was carried out focused on Geumsan-gun. As a result, it confirmed that rural out-migration and rural decline especially in 'people', 'land(economic situation)' and 'community' have being progressed. Also variance analysis and regression analysis were executed with using the number of population and the ratio of people over 65 as dependent variables and using each survey contents(variables) as independent variables. The results of analysis showed that the ratio of people over 65(+), the income level per household(-), the rate of fallow lands(+), the number of empty houses(+), programs for urban-rural interchange(+), and the implementing public projects(+), etc. have a relation with the number of population(-) and the number of population(-), the income level per household(-), the rate of fallow lands(+), the number of empty houses(+), activities of communities(+), and the implementing public projects(+), etc. have a relation with the ratio of people over 65(+) (+: increase, -: decrease). So the hollowization in people', 'land(economic situation)' and 'community' has direct relation with decrease and aging of population in rural areas.

• Industrial Engineering and Management Systems
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• 제10권3호
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• pp.197-202
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• 2011

In traditional production lines, such as assembly lines, each worker is usually assigned to a particular fixed work, and decreasing the task to master the assigned work is valuated. However, when an imbalance exists between workers' speeds, if a worker delays the overall work in the production line, the production rate of the particular line will also decrease. To avoid this problem, the "Self-Balancing Production Line" was introduced. In this type of production line, each worker is assigned work dynamically, and when specific conditions are satisfied, production remains balanced. Characteristics of these lines that can be preempted at any place have already been analyzed by some researchers. A previous paper examined the situation in which only a single worker can process one machine and cannot preempt processing, and the improved policy of an ordinary selfbalancing production line, which specifies which stations workers can process and how workers can behave. This policy achieveda high production rate with only four stations and two workers (Buzacott, 2002). In that paper, worker processing stations and the behavior of a specific worker were limited, andthe paper focused only on specific stations and workers. Therefore, it is not applicable to any worker sequence. In this paper, we focus on other ways to decrease cycle time. In this kind of line, a worker processes at his or her speed. Therefore, if a worker is assigned stations according to his or her speed, the line can decrease cycle time. To do so, we relax the assumptions of this type of line and set a new condition. Under these conditions, we compare our results to the results of previous papers.

• The Korean Journal of Physiology
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• 제3권2호
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• pp.17-23
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• 1969

Oxygen consumption rate $(QO_2)$ and protein content of liver and kidney of the Ehrlich ascites tumor-bearing mouse were measured from 6th till 14th day after the inoculation of $4{\times}10^6$ Ehrlich ascites tumor cells. The results thus obtained were compared with those of the groups in which; 1) Whole body x-irradiation with 400 r was done to mouse prior to the inoculation of $4{\times}10^6$ Ehrlich ascites tumor cells, 2) Same number of the irradiated tumor cells were inoculated after subjecting the tumor cells to x-irradiation with 400 r or 900 r in vitro, and 3) the normal, and the following results were obtained; 1. $QO_2$ of the liver and kidney of the tumor-bearing mouse were all lower than the normal and a gradual decrease of $QO_2$ in both liver and kidney was noted as the ascites tumor was progressively developing. 2. In the groups where whole body x-irradiation with 400 r was done, or x-irradiation of ascites tumor cells in vitro with either 400 r or 900 r, $QO_2$ of the liver and kidney were lower than the normal, and the pattern of the decrease was similar in the case of the tumor-bearing mouse. 3. Protein contents in all the groups showed lower values than the normal, and the decrease was gradual as the ascites tumor was developing. 4. $QO_2$ and protein levels in the liver were generally lower than those in the kidney. 5. A certain cancerous metabolism was, therefore, noted in the remote organs of Ehrlich ascites tumor-bearing animal.

• 열처리공학회지
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• 제12권2호
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• pp.136-144
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• 1999

The study on the wear characteristics of compound layers formed during gaseous nitrocarburising in the medium carbon boron steels and the plain carbon steel has been carried out by using a pin-on-disc type wear test machine under the oil lubricating condition at room temperature and by varying applied loads, sliding speeds and wear distances. Values of friction coefficient measured at the sliding speed of 0.4m/sec under the oil lubricating condition have been shown to decrease considerably with increasing applied load and become gradually a constant value as load is increased to a higher value, showing that the transition load for friction coefficient appears at an applied load of 247.2N. The length and volume wear rates of compound layer have been revealed to relatively constantly increase, also showing that the wear life per unit thickness of compound layer turns out to be superior as porous layer has a denser and thinner appearance. As the sliding speed increases during wear test performed by varying sliding speed at a load of 63.2N under the oil lubricating condition for medium carbon boron steel nitrocarburised in gas atmosphere, the wear rate has been found to increase, the friction coefficient to decrease and the wear life per unit thickness of compound layer to decrease considerably.

• 대한한의학회지
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• 제28권1호통권69호
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• pp.63-71
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• 2007

Objectives : To provide an objective assessment of the effectiveness for weight loss of Mahuang. Methods : Effects were assessed by measuring changes in body weight, body mass index (BMI), body fat (kg, %),body muscle, and abdominal f3t ratio. The subjects of this study were healthy adults who agreed to participate in this study. Eligibility requirements include age between 20 and 50 and BMI more than 18.5 kg/m2. One hundred subjects were randomly assigned to two groups (control and Mahuang group) in a double-blind manner. Mahuang group subjects took 8g of Mahuang capsule/day for two weeks; control subjects took the same amount of indistinguishable placebo. We analyzed the body weight, body mass index, body fat, abdominal fat, body muscle and BMR (basal metabolic rate) before and after the study. Result After two weeks of clinical trial, body weight and BMI decreased in both groups, but the Mahuang group showed more significant decrease. On body fat, the Mahuang group showed significant decrease. while it increased in the placebo group. Although body muscle, body fat ratio and basic metabolic rate showed differences between the two groups, there was no statistical significance. Conclusion : It is suggested that intake of Mahuang may induce weight loss and body f3f decrease in healthy adults.