• 제목/요약/키워드: Mass changes

Search Result 2,181, Processing Time 0.027 seconds

Effects of Localized Muscle Fatigue and Whole Body Fatigue on Postural Control during Single-Leg Stance

  • Youm, Chang-Hong;Shin, Joong-Dal;Lee, Joong-Sook;Seo, Kook-Eun;Park, Jong-Jin
    • Korean Journal of Applied Biomechanics
    • /
    • v.24 no.2
    • /
    • pp.111-119
    • /
    • 2014
  • The purpose of this study was to investigate the effects of localized muscle fatigue and whole body fatigue on postural control during single-leg stance after impairment induced by heel raise and the Harvard step test. Thirty-eight university students (19 men: age, $20.1{\pm}0.2$ yrs; height, $175.0{\pm}5.23cm$; weight, $66.8{\pm}5.6kg$; body mass index, $21.8{\pm}1.7kg/m^2$, 19 women: age, $20.6{\pm}1.1yrs$ ; height, $163.6{\pm}6.7cm$; weight, $58.8{\pm}4.6kg$; body mass index, $22.0{\pm}2.2kg/m^2$) were participated in this study. Subjects performed a series of single-leg postural tasks prior to, following, and 24 hours after completing: heel raise or the Harvard step test. This study showed that the root mean squared distance and velocity in the anteroposterior and mediolateral planes of the center of pressure decreased significantly due to heel raise exercise-induced fatigue. Furthermore, the root mean squared distance in the anteroposterior and mediolateral planes, and the 95% confidence ellipse area of the center of pressure also decreased significantly 24 hours after completing the Harvard step test. In conclusion, this study showed that both heel raise exercise- and Harvard step exercise-induced fatigue affects postural control during single-leg stance in AP and ML planes. Furthermore, this study suggests that changes in the postural control strategy may have occurred after the fatigue protocols during single-leg stance. Also vision can attenuate the postural deficits associated with the fatigues. In order to clarify these results, further studies using other equipment and variables are necessary.

Development of a comprehensive health promotion program for North Korean young adult defectors in South Korea (북한이탈 청소년을 위한 통합적 건강증진 프로그램 개발)

  • Choi, Seul-Ki;Park, Sang-Min;Joung, Hyo-Jee
    • Journal of the Korean Society of School Health
    • /
    • v.22 no.1
    • /
    • pp.73-83
    • /
    • 2009
  • Purpose: The purpose of this study was to develop a comprehensive health promotion program for North Korean young adult defectors in South Korea. Methods: The comprehensive health promotion program consisted of nutrition, mental healthcare, physical activity and sexual behavior was developed on the basis of need assessment results. For the evaluation of the program, 70 North Korean young adults who were attending two alternative schools for North Korean defectors were recruited. The program had taken place once a week for 13 or 19 weeks. Effectiveness of the health promotion program was evaluated using anthropometric measurement, 3-day food records and a questionnaires that comprised the Hospital Anxiety and Depression Scale (HADS), the Short Form with 36 questions (SF-36) and health behaviors. The surveys were proceeded at the beginning and after the program. Results: After health promotion program, participants' height was significantly increased (p=0.004) and body fat mass (0=0.004) and percentage of body fat mass (p=0.003) were significantly decreased. The number of subjects who ate breakfast alone was decreased whereas the number of subjects who ate breakfast with friends was increased (p<0.001). There were no significant changes in dietary intakes, mental health status and quality of life. North Korean young adult defectors' willingness to participate and interests in the health promotion program were high, however the practice rate was low. Conclusion: The health promotion program could induce interests and willingness to participate, but bring about limited effects on the health behaviors. These results imply that a health promotion program for North Korean young adult defectors should have a long-term strategy as well as short-term plan. Furthermore, it should be based on their health problems, health related behaviors, academic performance and daily life matters.

Characteristics of Washed-off Pollutants and Dynamic EMCs in a Parking Lot and a Bridge during Storms (주차장 및 교량지역의 강우유출수내 비점오염물질의 특성 비교 및 동적 EMCs)

  • Kim, Lee-Hyung;Lee, Seonha
    • Journal of Korean Society on Water Environment
    • /
    • v.21 no.3
    • /
    • pp.248-255
    • /
    • 2005
  • Since the water quality of drinking water sources has been recognized as a big issue, the ministry of Environment in Korea is designing the total maximum daily load (TMDL) program for 4 major large rivers. The TMDL program can be successfully performed as controling the nonpoint pollutants from watershed area near the river. Of the various landuses in nonpoint pollution, parking lots and bridges are stormwater intensive landuses because of high imperviousness and high pollutant mass emissions from vehicular activities. Vehicle emissions from those areas include different pollutants such as heavy metals, oil and grease and particulates from sources such as fuels, brake pad and tire wear, etc. Especially the pollutant washed-off from the landuses are directly affecting to the river water quality. Therefore this research was conducted to understand the magnitude and nature of the stormwater emissions with the goal of quantifying stormwater pollutant concentrations and mass emission rates of pollutants from parking lot and bridges in Korea. In Kongju city areas, two monitoring sites were equipped with an automatic rainfall gages and an automatic flow meter for accumulating the useful data such as rainfall, water quality and runoff flow. This manuscripts will show the concentration changes during storm duration and EMCs to characterize the concentration profiles in different land uses. Also the first flush criteria will be suggested using dynamic EMCs. The definition of dynamic EMC is a new approach explaining the relationship of EMC and first flush effect.

A Case of Foreign Body Laryngeal Granuloma Mimicking Contact Granuloma (접촉성 육아종으로 오인된 후두 이물 육아종 1예)

  • Kim, Hye soo;Kim, Sun woo;Lee, Jin;Lee, Sang Hyuk
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
    • /
    • v.31 no.1
    • /
    • pp.27-30
    • /
    • 2020
  • Among lesions in the larynx, laryngeal contact granuloma due to persistent tissue irritation can typically be attributed to endotracheal intubation, vocal abuse, or gastro-esophageal reflux disease. Treatment typically includes voice therapy, lifestyle changes and use of anti-reflux medication. Microsurgical removal is only indicated in cases of severe dyspnea due to mass size. Foreign body granuloma is a response of to any foreign material in the tissue. Foreign body granulomas are sometimes misdiagnosed as soft tissue tumors when the causative foreign body is not initially found. Delayed treatment of these foreign bodies may cause complications. We present a case of larynx granuloma due to impacted foreign body, probably fish bone, in the larynx that mimicked contact granuloma. We initially used anti-reflux medication, but to no avail. The laryngeal mass, observed through laryngoscopy, showed no improvement and therefore necessitated a proper pathologic diagnosis. We were able to successfully treat it via trans-oral laser CO2 microsurgery before any complications developed.

Effects of Physical Activity Program on Body Composition and Basic Motor Skills in Obese Children (신체활동 프로그램이 비만유아의 체성분과 기본운동능력에 미치는 영향)

  • Kim, Won-Jun;Na, Seung-Hee
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.11 no.11
    • /
    • pp.4266-4272
    • /
    • 2010
  • The purpose of this study was to find the effects of physical activity program on obese young children's body composition and basic motor skills. The physical activity program was conducted with 16 participants whose Kaup Index were higher than 20 were divided into 2 groups(experimental group and control group) for 12 weeks three times a week. Results of the study are as following. First, the physical activity program was found to improve sub-factors of body composition(weight, body fat mass, % body fat, lean body mass and total body water) in the experimental group compared to the control group. There was statistically significant difference between two groups. Second, the physical activity program was found to improve locomotor and manipulation skills of basic motor skills in the experimental group compared to the control group. There was a statistically significant difference between two groups. Based on these results, the physical activity program have positive effects on the changes in obese young children's body composition and basic motor skills.

Clinical Features of Conjunctival Dermolipoma (결막 유피지방종의 임상 양상)

  • Song, Hee Jun;Hwang, Ho Sik;Jung, Yoon Yang;Kwon, Ji Won
    • Journal of The Korean Ophthalmological Society
    • /
    • v.59 no.12
    • /
    • pp.1108-1113
    • /
    • 2018
  • Purpose: To evaluate the clinical features of conjunctival dermolipoma. Methods: We reviewed the ocular records of 18 consecutive patients diagnosed with dermolipoma in our hospital between March 2016 and March 2018. Results: The study population consisted of eight females and 10 males with a mean age of 61 months (range 3 months to 45 years old), with a pinkish conjunctival mass located at a mean of 4.7 mm (range 2-8 mm) from the temporal limbus and anterior to the lateral orbital rim. The mean visual acuity of eight patients in whom it was possible to measure visual acuity was 0.9 (range 0.6-1.0). Surgery was performed in two eyes. Pathological examination revealed conjunctival dermolipoma. Postoperatively, there was no evidence of visual changes or specific complications. Conclusions: Conjunctival dermolipoma may be suspected in cases with a congenital subconjunctival non-movable mass, which can be confirmed by computed tomography and pathological examination.

Effects of the Changes in Flow Pattern on Convective Heat Transfer in the Vicinity of Pipe Elbow (유동형태 변화가 배관 곡관부 대류열전달에 미치는 영향)

  • Song, Seung-Hyun;Yoo, Hoseon
    • Plant Journal
    • /
    • v.15 no.1
    • /
    • pp.25-30
    • /
    • 2019
  • In this study, by varying flow patterns, which is one of the hydraulic factors of FAC, a strategy to reduce pipe wall thinning by mass transfer has been investigated. A similarity between heat transfer and mass transfer was verified via theoretical analysis, and local convective heat transfer coefficients were analyzed using a commercial numerical analysis program. When ribs were installed inside and outside of the internal surface in the straight section of the pipe, the maximum local heat transfer coefficient was shown to decrease substantially by up to 24.9% compared to the basic flow depending on the position and shape of ribs. If a guide vein was inserted in the pipe elbow, the maximum local heat transfer coefficient decreased by up to 26.7% compared to the basic flow depending on the internal surface area of the pipe by the guide vein.

Short-Term Outcomes of Intracorporeal Delta-Shaped Gastroduodenostomy Versus Extracorporeal Gastroduodenostomy after Laparoscopic Distal Gastrectomy for Gastric Cancer

  • Kim, You Na;An, Ji Yeong;Choi, Yoon Young;Choi, Min-Gew;Lee, Jun Ho;Sohn, Tae Sung;Bae, Jae Moon;Kim, Sung
    • Journal of Gastric Cancer
    • /
    • v.19 no.1
    • /
    • pp.111-120
    • /
    • 2019
  • Background: Billroth I anastomosis is one of the most common reconstruction methods after distal gastrectomy for gastric cancer. Intracorporeal Billroth I (ICBI) anastomosis and extracorporeal Billroth I (ECBI) anastomosis are widely used in laparoscopic surgery. Here we compared ICBI and ECBI outcomes at a major gastric cancer center. Methods: We retrospectively analyzed data from 2,284 gastric cancer patients who underwent laparoscopic distal gastrectomy between 2009 and 2017. We divided the subjects into ECBI (n=1,681) and ICBI (n=603) groups, compared the patients' clinical characteristics and surgical and short-term outcomes, and performed risk factor analyses of postoperative complication development. Results: The ICBI group experienced shorter operation times, less blood loss, and shorter hospital stays than the ECBI group. There were no clinically significant intergroup differences in diet initiation. Changes in white blood cell counts and C-reactive protein levels were similar between groups. Grade II-IV surgical complication rates were 2.7% and 4.0% in the ECBI and ICBI groups, respectively, with no significant intergroup differences. Male sex and a body mass index (BMI) ${\geq}30$ were independent risk factors for surgical complication development. In the ECBI group, patients with a BMI ${\geq}30$ experienced a significantly higher surgical complication rate than those with a lower BMI, while no such difference was observed in the ICBI group. Conclusion: The surgical safety of ICBI was similar to that of ECBI. Although the chosen anastomotic technique was not a risk factor for surgical complications, ECBI was more vulnerable to surgical complications than ICBI in patients with a high BMI (${\geq}30$).

Comparison of Physical Characteristics and Lower Extremity Biomechanics of Elderly and Young Adult Runners (노인 러너의 신체특성과 하지관절의 생체역학적 비교)

  • Kim, Jong-Bin;Ha, Sunghe;Park, Sangheon;Yoon, Sukhoon;Ryu, Ji-seon;Park, Sang-Kyoon
    • Korean Journal of Applied Biomechanics
    • /
    • v.29 no.3
    • /
    • pp.145-155
    • /
    • 2019
  • Objective: The purpose of this study was to compare the physical characteristics (bone mineral density, joint muscle strength) and running biomechanics between older adults and young adult runners to understand the changes of running strategy by aging. Method: Bone mineral density (Dual Energy X-ray Absorptiometry, USA) of lower lower extremity and muscle strength (Cybex Humac Norm [DEXA], CSMI, USA) were measured to identify the physical characteristics of 10 elderly (age: $67.70{\pm}3.30yrs$, height: $1.68{\pm}0.04m$, mass: $67.70{\pm}3.80kg$) and 10 young adults (age: $21.20{\pm}0.42yrs$, height: $1.73{\pm}0.06m$, mass: $72.11{\pm}4.15kg$). Running data was collected by using an instrumented treadmill (Bertec, USA) and 7 infrared cameras (Oqus 300, Qualisys, Sweden). Two-way repeated ANOVA analysis was used to analyze results at a significant level of .05 with Bonferroni post hoc analysis. Results: Compared to the young adult group, the elderly group showed statistically significant difference in physical characteristics and in running characteristics. Elderly runners showed lower BMD and muscle strength compared with young runners (p<.05). In the running parameters, elderly runners tend to show shorter contact time and stride length compared with young runners (p<.05). In the joint angles, elderly runners showed smaller range of ankle motion compared with young runners (p<.05). Finally, elderly runners showed lower level of joint moment, joint power, and GRF compared with young runners in each running speed (p<.05). Conclusion: The running behavior of the elderly performed periodic running was similar to many variables of young adults. However, there were noticeable differences found in the ankle joints and most kinetic variables compared with young adult runners. This discrepancy may propose that elderly runners should consider appropriate running distance and intensity in the program.

Changes in Fire Characteristics according to the Distance Between the Fire Source and Sidewall in a Reduced-Scale Compartment (축소 구획실에서 화원과 측벽의 거리에 따른 화재특성 변화)

  • Yun, Hong-Seok;Hwang, Cheol-Hong
    • Fire Science and Engineering
    • /
    • v.33 no.1
    • /
    • pp.50-59
    • /
    • 2019
  • Experimental and numerical studies on the fire characteristics according to the distance between the fire source and sidewall under the over-ventilated fire conditions. A 1/3 reduced ISO 9705 room was constructed and spruce wood cribs were used as fuel. Fire Dynamics Simulator (FDS) was used for fire simulations to understand the phenomenon inside the compartment. As a result, the mass loss rate and heat release rate were increased due to the thermal feedback effect of the wall in the compartment fire compared to the open fire. As the distance between the fire source and sidewall was reduced, the major fire characteristics, such as maximum mass loss rate, heat release rate, fire growth rate, temperature, and heat flux, were increased despite the limitations of air entrainment into the flame. In particular, a significant change in these physical quantities was observed for the case of a fire source against the sidewall. In addition, the vertical distribution of temperature was changed considerably due to a change in the flow structure inside the compartment according to the distance between the fire source and sidewall.