• 한국자동차공학회논문집
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• 제18권1호
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• pp.86-92
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• 2010

The fuel is not injected when the driver doesn't push acceleration pedal of a vehicle with engine speed higher than about 1,500rpm above mid vehicle speed range. This is called "fuel-cut function" and almost every modern vehicle is equipped with this function. This is activated on downhill part of a highway most often. Therefore the vehicle-exhausted $CO_2$ can be zero in this downhill part if the driver could recognize this part of highway. We compared the vehicle-exhausted $CO_2$ emission when using fuel-cut function with the $CO_2$ mass when without using this function in this study. We found that the $CO_2$ emission reduced with fuel-cut function and measured the reduction rate of vehicle-exhausted $CO_2$ mass with this test results. The exhausted $CO_2$ mass of a passenger car(2,000cc engine volume) is reduced by 4% with this function used. This $CO_2$ reduction effect can be achieved if the downhill part of a highway is painted with a specific color. And this road painting can be included in the highway road rehabilitation policy.

• Gut and Liver
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• 제12권6호
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• pp.633-640
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• 2018

Background/Aims: Obesity is a risk factor for gastroesophageal reflux disease (GERD), with several studies demonstrating positive associations between body mass index (BMI) and GERD symptoms. However, little is known about the effect of BMI changes on erosive esophagitis (EE). In this study, we investigated whether BMI reduction could resolve EE. Methods: A retrospective cohort study was performed to assess the natural course of EE according to changes in BMI. Participants undergoing health check-ups from 2006 to 2012 were enrolled, and 1,126 subjects with EE were included. The degree of esophagitis was measured by upper endoscopy and serially checked over a 5-year follow-up. Logistic regression and Cox proportional hazards models were used to investigate the association between BMI reduction and EE resolution. Results: Substantial weight loss is associated with EE resolution. The adjusted odds ratio for EE resolution was 1.44 (95% confidence interval [CI], 1.09 to 1.92) among participants with a decrease in BMI compared to those with no decrease in BMI. The EE resolution rate was related to the degree of BMI reduction. The effect of weight loss on EE resolution was higher among subjects who lost more weight. Compared with subjects with no decrease in BMI, the hazard ratios for EE resolution were 1.09 (95% CI, 0.89 to 1.35), 1.31 (95% CI, 1.01 to 1.72) and 2.12 (95% CI, 1.44 to 3.12) in subjects with BMI reductions of ${\leq}1$, 1-2, and >$2kg/m^2$, respectively. Conclusions: EE resolution is associated with a decrease in BMI, and weight loss is potentially an effective GERD treatment.

• Journal of Mechanical Science and Technology
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• 제18권12호
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• pp.2303-2309
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• 2004

Flue gas recirculation (FGR) is a method widely adopted to control NOx in combustion system. The recirculated flue gas decreases flame temperature and reaction rate, resulting in the decrease in thermal NO production. Recently, it has been demonstrated that the recirculated flue gas in fuel stream, that is, the fuel induced recirculation (FIR), could enhance a much improved reduction in NOx per unit mass of recirculated gas, as compared to the conventional FGR in air. In the present study, the effect of FGR/FIR methods on NOx reduction in turbulent swirl flames by using N$_2$ and CO$_2$ as diluent gases to simulate flue gases. Results show that CO$_2$ dilution is more effective in NO reduction because of large temperature drop due to the larger specific heat of CO$_2$ compared to N$_2$ and FIR is more effective to reduce NO emission than FGR when the same recirculation ratio of dilution gas is used.

• 한국자동차공학회논문집
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• 제11권4호
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• pp.94-101
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• 2003

Recently, miniaturization and weight reduction is getting more attention due to various benefits in automotive components design. It is a trend that the design of experiment(DOE) and statical design method are frequently used for optimization. In this research, the safety of lower control arm is evaluated according to its material change form S45C to A16061 for the reduction of arm's weight. The variance analysis on the basis of structure analysis and DOE is applied to the lower control m. We have proposed a statistical design model to evaluate the effect of structural modification by performing the practical multi-objective optimization considering mass, stress and deflection.

• Journal of Nutrition and Health
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• 제36권9호
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• pp.924-932
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• 2003

In middle-aged men, abdominal obesity has been an important risk factor of coronary artery disease (CAD) as well as a predictor of hypertension, dyslipidemia, insulin resistance and glucose intolerance. Particularly, risks from abdominal obesity increase when adipose tissue accumulates in visceral compartment. Many studies showed that weight reduction by caloric restriction improves abdominal obesity and reduces lots of cardiovascular risk factors. Testosterone treatment also results in a significant decrease in visceral fat area and normalizes endocrine metabolism. However there is no study that compare the effect of caloric restriction with that of testosterone treatment. The purpose of this study is to investigate the effect of caloric restriction and that of testosterone treatment on body fat distribution, serum lipids and glucose metabolism in male patients with CAD. Forty five middle-aged overweight-obese men with CAD participated in 12 weeks' program. They were matched with age, body weight, body mass index (BMI) and divided into three groups : control group (n = 15) , caloric restriction group (-300 kcal/day, n = 15) and testosterone treatment group (testosterone undecanoate tablets, n = 15) . After 12 weeks, control group did not have any changes in anthropometries, lipid profile, body fat distribution, glucose metabolism and hormonal status. Expectedly, caloric restriction group showed decreases in body weight, BMI, waist to hip ratio, ％ body fat. Ten percentage of total cholesterol and 23% of triglyceride in serum were also decreased. In body fat distribution, total fat areas at both L1 and L4 levels were significantly reduced in this group without reduction in muscle of thigh and calf. However, testosterone treatment group did not have any significant changes in body weight, ％ body fat, serum lipid profile and abdominal fat distribution. In conclusion, weight reduction by caloric restriction is more beneficial in body fat distribution and serum lipid level than testosterone treatment in overweight male patients with CAD. This result suggests that modest weight reduction is possible to help decrease risk factors of CAD.

• 한방비만학회지
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• 제20권1호
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• pp.20-30
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• 2020

Objectives: The purpose of this study is to verify the effects of H Gambitang (GB-001) on body composition and basal metabolic rate in pre- and post-menopausal obese woman retrospectively. Methods: The study was conducted on 57 middle-aged obese women. They were divided into two groups; pre-menopausal obesity group (Pr-MOG; n=34) and post-menopausal obesity group (Po-MOG; amenorrhea was continued to 14~48 month, n=23) with no significant difference of age, height, body weight and body mass index. All subjects took herbal medicine 3 times a day, for 6 weeks during treatment period. The weight, height, body fat mass, skeletal muscle mass, and basal metabolic rate of all subjects were measured on first visit. The following measurements were repeated after 2 weeks (2nd), 4 weeks (3rd) and 6 weeks (4th) with Inbody 370 (Biospace) equipment to identify changes of body fat mass, skeletal muscle mass, and basal metabolic rate. Results are represented as mean and standard deviation. Results: Po-MOG showed significantly lower decrease rate in weight reduction on 2~6 weeks while significantly higher decrease rate in skeletal muscle reduction on 4~6 weeks. There were no significant differences between two groups in body fat reduction rate and basal metabolic increasing rate. Conclusions: H Gambitang (GB-001) can be used not only in Pr-MOG but in Po-MOG in weight loss although the effect can be lower in Po-MOG. To prevent skeletal muscle mass loss in Po-MOG, following study on adjusting dose and components of H Gambitang (GB-001) thought to be necessary.

• 한국응용과학기술학회지
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• 제38권2호
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• pp.453-464
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• 2021

바쁜 일상 속에서 신체 활동량의 감소와 식생활의 서구화 등으로 인한 복부 비만의 발생률이 높아지고 있다. 따라서 체형 관리에 대한 욕구를 충족시키기 위해 시간 대비 고 효율의 관리 프로그램이 필요하다. 본 연구에서는 전기근육자극요법 (electric muscle stimulation therapy)을 활용하여 다이어트젤(슬리밍 화장품)과의 복합사용에 의하여 허리둘레 및 체지방량 (또는 복부의 지방)를 감소 효과를 촉진시켰다. 연구 대상자는 20대 성인 남녀로 다이어트젤을 허리 부위에 단순 도포를 한 후, 그 위에 EMS를 착용하여 기상 후와 취침 전에 1일 2회 20분간 마사지를 실시하였다. 실험 기간은 2주 동안 실시되었다. 지방분해 촉진 효과는 비 조영 CT를 활용하여 피하지방의 감소에 대한 관찰이 되었으며, 이와 함께 허리둘레와 체지방량 측정으로 확인되었다. 결론적으로 개발된 EMS와 다이어트젤의 동시 사용 프로그램은 약 3 cm (p<.001)의 허리둘레 감소와 약 1 kg (p<.01)의 체지방량 감소를 나타내어 허리라인 관리에 탁월한 효과가 있음을 입증하였다. 이는 EMS의 활용이 근육 자극에 의한 마사지 효과를 나타내며 다이어트젤의 흡수를 도와 지방 분해를 촉진시키는 역할을 하는 것으로 사료된다.

• Archives of Plastic Surgery
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• 제38권3호
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• pp.257-262
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• 2011

Purpose: In neurofibromatosis patients, complete surgical excision of the mass is almost impossible and surgical treatment usually consists of multiple serial excisions that only result in a debulking effect. Remnant tumor mass has a gravitational effect on facial soft tissues that leads to sagging of skin and soft tissue, and eventually, facial disfigurement and asymmetry. The purpose of our surgical method is to perform soft tissue lifting with longer lasting effect with less surgical risk of damaging facial nerve and vessels. With external fixation using K-wire or surgical screw, the procedure only called for a short incision length and had additional adhesive properties that enabled anchoring of soft tissue in a lifted position for a longer postoperative period. Methods: A total of 5 neurofibromatosis patients (NF-1) visited our clinic for mass reduction and face lifting. The age of patients ranged from 13 to 42 (mean 28.8 years), and most patients had a long history of multiple excisions in the past. Face lifting was performed in 2 different areas, the periorbital area in 3 patients, and the midface in 2 patients. The materials used in fixation of retaining ligament were K-wire (n=3) and titanium screw (n=2). Results: Follow up period was from 5 month to 3 years and 1 month (mean=2 years and 1 month). All patients conveyed satisfaction with the results and no major complications were reported. The lifting effect lasted for as long as 3 years, and there were no complaints of relapse of soft tissue depression or sagging within the operated area. 1 patient (M/13) needed secondary k-wire insertion and additional mass excision in 1 year and 10 months postoperatively due to tumor growth. In two patients with K-wire fixation, mild dimpling and tenderness were observed in the follow up period, but in about 2 months postoperatively, dimpling was relieved and there was no need for removal of fixating material. Conclusion: Surgical lifting in neurofibromatosis patients can be challenging, for mass excision cannot be done completely and gravitational effect by residual mass can be persistent. External fixation of the retaining ligament in patients with neurofibromatosis can give satisfactory results-for incision length is relatively shorter, and the lifting effect can last longer compared to other various face lifting techniques.

• Structural Engineering and Mechanics
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• 제74권1호
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• pp.129-143
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• 2020

This study proposes a new shape memory alloy-tuned mass damper (SMA-TMD) and investigates the effectiveness of this damper in reducing and controlling the vibrations of a transmission tower-line system under various seismic excitations. Based on a practical transmission line system and considering the geometric nonlinearity of this system, the finite element (FE) software ANSYS is used to create an FE model of the transmission tower-line system and simulate the proposed SMA-TMD. Additionally, the parameters of the SMA springs are optimized. The effectiveness of a conventional TMD and the proposed SMA-TMD in reducing and controlling the vibrations of the transmission tower-line system under seismic excitations is investigated. Moreover, the effects of the ground motion intensity and frequency ratio on the reduction ratio (η) of the SMA-TMD are studied. The vibration reduction effect of the SMA-TMD under various seismic excitations is superior to that of the conventional TMD. Changes in the ground motion intensity and frequency ratio have a significant impact on the η of the SMA-TMD. As the ground motion intensity and frequency ratio increase, the η values of the SMA-TMD first increase and then decrease. Studying the vibration reduction effects of the SMA-TMD can provide a reference for the practical engineering application of this damper.

• Earthquakes and Structures
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• 제17권2호
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• pp.175-189
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• 2019

The aim of the study is to show the results of complex shaking table experimental investigation focused on the response of two models of cylindrical steel tanks under mining tremors and moderate earthquakes, including the aspects of diagnosis of structural damage. Firstly, the impact and the sweep-sine tests have been carried out, so as to determine the dynamic properties of models filled with different levels of liquid. Then, the models have been subjected to seismic and paraseismic excitations. Finally, one fully filled structure has been tested after introducing two different types of damages, so as to verify the method of damage diagnosis. The results of the impact and the sweep-sine tests show that filling the models with liquid leads to substantial reduction in natural frequencies, due to gradually increasing overall mass. Moreover, the results of sweep-sine tests clearly indicate that the increase in the liquid level results in significant increase in the damping structural ratio, which is the effect of damping properties of liquid due to its sloshing. The results of seismic and paraseismic tests indicate that filling the tank with liquid leads initially to considerable reduction in values of acceleration (damping effect of liquid sloshing); however, beyond a certain level of water filling, this regularity is inverted and acceleration values increase (effect of increasing total mass of the structure). Moreover, comparison of the responses under mining tremors and moderate earthquakes indicate that the power amplification factor of the mining tremors may be larger than the seismic power amplification factor. Finally, the results of damage diagnosis of fully filled steel tank model indicate that the forms of the Fourier spectra, together with the frequency and power spectral density values, can be directly related to the specific type of structural damage. They show a decrease in the natural frequencies for the model with unscrewed support bolts (global type of damage), while cutting the welds (local type of damage) has resulted in significant increase in values of the power spectral density for higher vibration modes.