• 대한인간공학회지
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• 제33권3호
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• pp.215-227
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• 2014

Objective: The purpose of this study was to evaluate Korea's Honam express train's first- and second-class seat discomfort by using pressure measurement, subjective discomfort rating, and physical compatibility. Background: Over the years, the demand for an express train service is continually increasing. A comfortable ride is important to achieving passenger satisfaction. A train seat plays a significant role in fulfilling passenger seating comfort. With this in view, a field survey and pressure measurements were performed on the selected train seat. Method: The pressure ratio at the body-seat interface (thigh and buttock regions) was measured by the pressure mat system. The interface pressure ratio was calculated and compared. The subjective discomfort rating scale was used to evaluate the subjects' overall feeling. The dimensions of train seats were analysed according to the anthropometric and demographic characteristics of the population data from Size Korea. Results: The results highlighted that the interface pressure ratio was greater while participants sat on the second-class seat than the first-class seat in the left- and right-side thigh regions. Also the pressure ratio was greater for the participants in the 1st~25th percentile height groups (149.8~160.8cm). The subjects rated higher discomfort for the second-class seat than the first-class seat. The physical compatibility results showed that the second-class seat's breadth was inadequate for the 95th and 99th percentile male. Conclusion: Overall, interface pressure measurement, subjective discomfort score and physical compatibility results showed that the second-class seat was more uncomfortable for the passengers than the first-class seat. Application: The adopted methodologies could be used to measure the seating comfort of the train seats.

• 대한통합의학회지
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• 제11권3호
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• pp.25-33
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• 2023

Purpose : Stabilization exercise and respiratory muscle training are used to train trunk muscles that affect postural control and respiratory function. However, there have been no studies that combine stabilization exercise and respiratory muscle training. The purpose of this study is to investigate effects of stabilization exercise with and without respiratory muscle training on respiratory function and postural sway. Methods : Fifteen healthy adults were recruited for this experiment. All the subjects performed stabilization exercise with and without respiratory muscle training. For stabilization exercise with respiratory muscle training, the subjects sat on a gym ball wearing a stretch sensor. The subjects inspire maximally as long as possible during lifting one foot off the ground, alternately for 30 seconds. The stretch sensor was placed on both anterior superior iliac spine (ASIS), and the stretch sensor was used to monitor inspiration. For stabilization exercise without respiratory muscle training, the subjects sat on a gym ball and lifted one foot off the ground, without respiratory muscle training. Kinovea program used to investigate postural sway tracking during exercise. The maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP) were measured using a spirometer to investigate changes of respiratory muscle strength before and after exercise. A paired t-test was used to determine significant differences postural sway tracking, MIP, and MEP between stabilization exercise with and without respiratory muscle training. Results : There were significantly lower a distance of postural sway tracking during stabilization exercise with respiratory muscle training, compared with stabilization exercise without respiratory muscle training (p<.05). The MIP and MEP were significantly increased after stabilization exercise with respiratory muscle training compared with before stabilization exercise with respiratory muscle trianing (p<.05). Conclusion : The results of this study suggest that stabilization exercise with repiratory muscle training would be recommended to improve postural control and respiratory muscle strength.

• 한국자원식물학회지
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• 제24권4호
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• pp.413-418
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• 2011

P-V 곡선을 적용하여 참취와 수리취의 수분특성인자를 측정한 결과 최대포수시의 삼투포텐셜 ${\Psi}^{sat}_o$과 초기원형질 분리점의 삼투포텐셜 ${\Psi}^{tlp}_o$은 참취가 수리취보다 낮은 값을 나타냈으나 큰 차이를 보이지는 않았다. 최대팽압 ${\Psi}_{P,max}$는 참취가 수리취에 비해 높게 나타났으며, 최대탄성계수 $E_{max}$는 참취가 수리취에 비해 약 2.4배 정도 높은 값을 나타냈다. 초기원형질분리점에서의 상대함수율 $RWC^{tlp}$은 참취와 수리취 모두 90% 이상의 함수율을 보여 비교적 삼투 조절기능이 좋은 것을 알 수 있었고, apoplastic water의 비율은 참취가 더 크며, Vo/DW, Vt/DW, Ns/DW은 수리취가 참취에 비해 약 1.5~2.0배 정도 큰 경향을 보였다. 위 결과를 통해 참취와 수리취 모두 초기원형질분리점과 최대포수시의 삼투포텐셜이 높은 편으로 내건성은 비교적 약한 것으로 나타났으며, 습윤한 지역이 생육에 적합함을 알 수 있었다. 또한, 참취와 수리취를 비교할 때 참취가 수리취에 비해 건성잎의 특성을 가지고 있으며, 최대탄성계수와 삼투포텐셜이 높아 내건성이 약간 더 강한 것을 알 수 있었다.

• 대한물리치료과학회지
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• 제26권2호
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• pp.32-37
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• 2019

Background: The purpose of this study is to investigate the change of blood pressure and autonomic neural system through one-time bamboo stepping in hypertensive elderly people. Design: Randomized Controlled Trial. Methods: We recruited 26 elderly people aged 65 or older for study. They sat for 10 minutes in a chair, rested, and measured pre-exercise blood pressure and autonomic neural system. The blood pressure was measured three times and the mean value was used and the autonomic neural system was measured once. Bamboo stepping exercise was performed for 20 minutes. Blood pressure and autonomic neural system were measured 5 times immediately after exercise, and every 15 minutes at 60 minutes after bamboo stepping exercise. Results: There was a significant difference in the decrease of systolic blood pressure after one-time bamboo stepping exercise, the change of parasympathetic activity (HF), heart rate variability (HRV) and BPM measured immediately after exercise at 15 minutes after exercise, There was no significant difference in autonomic neural system change. Conclusion: One-time Bamboo stepping exercise is effective in decreasing systolic blood pressure of the hypertensive elderly.

• 한국구조물진단유지관리공학회 논문집
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• 제4권1호
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• pp.101-110
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• 2000

In case heavy rainfall is a key factor of slope failure, the failure zone is usually developed within the depth of 3~5m from the ground surface regardless of the location of the watertable. If rainfall is taken into consideration, it is general that the slope stability analysis is carried out under the assumption that the cut slope is saturated to the slope surface or the watertable elevates to a certain height so that ${\gamma}_{sat}$, the unit weight of saturated soil, is used. However, the analysis method mentioned above can't exactly simulate the variation of pore water pressure in the slope and yields different failure shape. The applicability of slope stability analysis method considering the distribution of pore water pressure within the slope with heavy rainfalls, was checked out after the stability analysis of a lage-scale cut slope in a highway construction site, where surface failure occurred with heavy rainfalls. An appropriate slope stabilization method is proposed on the base of the outcome of the analysis.

• 한국작물학회지
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• 제44권1호
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• pp.55-58
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• 1999

Plant water status during growth is directly and indirectly associated with seed yield. The objective of the present study was to determine the genotypic differences in leaf water characteristics at an early growth stage of soybean [Glycine max (L.) Merrill] plants through the pressure-bomb technique. Measurements of water potential as well as relative water content (RWC) were made at the third leaf from the fully-expanded top leaf of eight different soybean genotypes grown for 31 to 35 days after field emergence. On the basis of the modified exponential model, pressure-volume (PV) curves were fitted well ($R^2$=0.92＊＊ to 0.99＊＊ for the curvi-linear region and R=0.67＊＊ to 0.96＊＊ for the linear region), indicating that a segmented model using PROC NLIN of SAS could be used effectively to estimate the leaf water characteristics. The regression analysis for the pressure-volume (PV) curve revealed genotypic variation in the solute potential at saturation (Ψ$_{s,sat}$ :-10.7 to -14.8 bar), solute potential at incipient plasmolysis (Ψ$_{s,ip}$ : -14.3 to -18.3 bar), RWC at incipient plasmolysis (RW $C_{ip}$ : 83.3 to 91.7%), high integrated turgor pressure from saturation to plasmolysis ( $_1$$^{b}$ : 0.39 to 0.81), and maximum volumetric modulus of elasticity ($\varepsilon$$_{max}$ : 150 to 445 bar).).

• 대한의용생체공학회:의공학회지
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• 제44권2호
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• pp.157-165
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• 2023

The purpose of this study was to evaluate the importance of developing slim seats with ergonomic design to improve seat comfort and expand the interior space. Two seats were used for the experiment: a sample seat designed based on hip shape and spinal alignment and a normal seat with a flat design without curves. Subjects sat in both the sample seat and a normal seat applied to the vehicle simulator and the experiment was conducted. The next part of the experiment was conducted in two different postures: a driving posture and a relaxed posture. The subjects filled out a comfort questionnaire immediately after sitting and after 30 minutes. The results showed that the comfort in the sample seat was found to be more comfortable than the normal seat. However, no significant difference was noted for the relaxation posture. Pressure distribution was also recorded immediately after sitting and after 30 minutes. In the case of pressure distribution, it was confirmed that the pressure in the sample seat was more evenly distributed in both the driving and relaxed postures than in the normal seat. The results showed that the ergonomically designed sample seat greatly improved seating comfort and pressure distribution compared to the normal seat, which is a general vehicle seat design.

• 한국산림과학회지
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• 제99권1호
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• pp.131-135
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• 2010

본 연구는 P-V 곡선법을 적용하여 곰취, 곤달비, 한대리곰취의 내건성 진단과 적지재배 환경의 구명을 위해 수행되었다. 최대팽압시 삼투포텐셜 ${\Psi}_{\circ}{^{sat}}$은 곰취와 곤달비가 -0.8MPa로 한대리곰취(-0.7 MPa)보다 낮았다. 초기원형질분리점의 삼투포텐셜 ${\Psi}_{\circ}{^{tlp}}$은 곰취와 곤달비가 -0.9 MPa로 한대리 곰취(-0.8MPa)보다 낮게 나타났다. 최대탄성계수 $E_{max}$는 곰취와 곤달비가 29 MPa로 한대리곰취의 14.5MPa 보다 약 2배 가량 높았다. 초기원형질분리점에서의 상대함수율은 곰취 95%, 곤달비 93%, 한대리곰취가 94%로 비슷한 값을 나타냈다. 따라서 곰취류는 비교적 내건성이 약하고, 함수율이 매우 높은 상태에서 초기원형질분리가 일어나므로 비교적 습윤한 지역이 생육에 적합함을 알 수 있었다.

• 대한임상독성학회지
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• 제9권1호
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• pp.8-13
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• 2011

Purpose: Although glyphosate-surfactant herbicide intoxication is relatively mild toxic in humans, we encountered an atypical clinical presentation. We performed this study to understand the atypical clinical course and factors associated with severe intoxication after glyphosate ingestion. Methods: We conducted a retrospective study of 61 patients (male 43, mean age $54{\pm}18.8$ years) who were presented with glyphosate ingestion between March 1997 and March 2011. The severe intoxication group was defined as patients with systolic blood pressure less than 90 mmHg, respiratory distress needing intubation, or altered mental state. Results: Of the 61 patients, 22 patients (36.1%) had a severe clinical course, 1 patient (1.6%) had died and 1 patient (1.6%) had moribund discharge. The most common symptoms were nausea with or without vomiting which occurred in 30 patients (49.2%). Twenty-seven patients had metabolic acidosis that was the second most common medical complication. Advanced age, pH, base excess, $HCO_3$, Sat, creatinine, X-ray abnormalities and ECG abnormalities were significant factors. Hemoglobin, platelet, $pO_2$, $pCO_2$, BUN, sodium, potassium and AST levels were not different comparing the laboratory characteristics between the severe and mild intoxication groups. Conclusion: The results of this study showed that severe intoxication occurred in 22 patients (36.1%) after glyphosate intoxication. Advanced age, pH, base excess, $HCO_3$, Sat, creatinine, X-ray abnormality and ECG abnormalities were significant predictive factors for severe intoxication in patients with glyphosate surfactant herbicide poisoning.

• 드라이브 ㆍ 컨트롤
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• 제16권4호
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• pp.1-8
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• 2019

The HPM (High-speed Power Matching) system is an electro-hydraulic control system. It directly controls the swash plate of the pump by selecting four-loop logic based on joystick signals, pump flow, and pressure signal to improve the efficiency and controllability of construction machines. In the NFC (Negative Flow Control) system, a typical pump control system using conventional open center type MCV, the loss is continuously generated by flow through the center bypass line even when the excavator is not in operation. Also, due to the slow response of the pump that indirectly controls the flow rate using the pressure regulator, peak pressure occurs at the start or stop of the operation. Conversely, the HPM system uses an MCV without center-by-pass flow path and the swash plate of a pump for the HPM is controlled by a high-speed proportional flow control valve. As a result, the HPM system minimizes energy loss in standby state of the excavator and enables peak pressure control through rapid electro-hydraulic control of a pump. In this paper, the concept of the HPM system algorithm is introduced and the hydraulic system efficiency is compared with the NFC system using the excavator SAT (System Analysis Tool).