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

• 대한전자공학회논문지SP
• /
• 제40권4호
• /
• pp.275-285
• /
• 2003

최근 표준화가 완성된 H.264는 가변 크기 블록 움직임 보상, 복수 참조 영상, 그러고 1/4 화소 움직임 벡터 정확도를 지원하고 있다. 그러나 이러한 새로운 부호화 기술은 부호화 효율 향상의 주된 요인이 되긴 하지만 동시에 높은 복잡도의 요인이기도 하다. 따라서 H.264 비디오 표준의 실제 응용 확대를 위해서는 이러한 기술에 대한 속도 향상이 필요하다. 본 논문에서는 부호화 복잡도의 가장 큰 비중을 차지하는 움직임 벡터 추정을 고속화하기 위해 가변 크기 블록 움직임 보상에 적합한 고속 움직임 벡터 탐색법을 제안한다. 또한 H.264가 갖는 다양한 부호화 모두 중 최적치를 빠르게 결정한 수 있는 고속 결정법을 제안한다. 실험 결과, 고속 움직임 벡터 탐색법은 기존 MVFAST/sup ［8-10］/에 비해 SAD 계산 수가 4.5배, SATD 계산수는 2.6배 감소하였으며, 고속 모드 결정법의 사용으로 비트율­왜곡 계산치인 RDcost 계산 수는 45%가 감소되었다. 따라서 제안된 방법은 큰 부호화 손실 없이 계산량 감소에 있어서 매우 높은 효율을 제공함을 확인하였다.

• 드라이브 ㆍ 컨트롤
• /
• 제16권4호
• /
• pp.1-8
• /
• 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).

• 한방비만학회지
• /
• 제8권1호
• /
• pp.81-88
• /
• 2008

Objectives To investigate the relationship between Heart Rate Variability and menopause among obese middle-aged women in Korea. Subjects and Methods Forty middle-aged women (age 49.05 $\pm$ 2.64 years) with BMI > $23kg/m^2$ were recruited by local advertisement. Blood profiles of estrogen, FSH, LH, glucose, total cholesterol, HDL-cholesterol, and triglyceride were measured. Autonomic Nervous System (ANS) was estimated by short-term spectral analysis of heart rate variability (HRV). Visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were accessed using Computerized Tomography (CT), Bioimpedance Analysis (BIA), and anthropometry. To scrutinize the influence of ANS on obesity-related factors, we divided the subjects into pre- and post-menopausal women. Results The total cholesterol, FSH and LH were significantly higher in post-menopausal obese women group. The estradiol and standard deviation of all normal R-R intervals (SDNN), high-frequency components (HF) of the HRV were significantly lower in postmenopausal obese women group (P<0.05). Adipose tissue distribution and blood profiles were not significantly different between two groups. Conclusion Menopause induced a decrease in SDNN and HF values and increase in total cholesterol level in obese women although the VAT itself was not related with ANS in obese women.

• 수산해양기술연구
• /
• 제51권3호
• /
• pp.312-320
• /
• 2015

The 1/5 scale-down model of the Bycatch Reduction Device (BRD) from an Argentinean demersal trawl was tested in a circulating water channel. The BRD is designed to help small Hake (merluza, merluccius hubbsi) to escape from a trawl. It is settled in front of a trawl codend, and is equipped with selection grids that help small fish to escape from the gear and guiding panels that help fish to meet with the grids. Bars of the grids are wires covered by the PVC and other parts of the BRD are made of net. When the velocity was less than 0.65 m/sec (2.81 Kont when translated to real towing speed) which is slow speed compared with real towing speed, position between an upper guiding panel and an upper selection grid were good to help small fish to escape. When the velocity was more than 0.8 m/sec (3.41 Knot when translated to real towing speed) which is similar to and faster than real towing speed, it was considered that small fish may have difficulties in escaping because the gap was not enough between an upper guiding panel and an upper selection grid. The lower selection grid was sat on the bottom of the tank without an angle due to the weight that it carries. Improvements were proposed to position the panels and the grids better.

• 대한가정학회지
• /
• 제39권10호
• /
• pp.97-109
• /
• 2001

It is thought that a composition of trousers is related to fabrics with single breadth. Therefore, trousers are designed with pattern using this fabrics with single breadth. However, in the old pattern of trousers, the breadth of 33cm-35cm was not considered in designing patterns. In this context, deciding which pattern design is better is not easy as there are a variety of estimation methods. So in this study, standardization of drafting is pursued by an objective pattern design. For this, a base angle of the trouser closely relating to a form and function was measured and using the height and the base angle, a trouser pattern design was tried. For a measurement of the base angle, 5 subject were selected. They are 25-29 year-old male graduates with fine physical standard. The base angle was measured with symphysis pubis point as a standard when subjects sat with their legs crossed, when they stood with their legs open (not forced artificially) and when they laid down with their legs open. The distance between a knee inside joint and knees was measured three times and the resultant value was used for the pattern design. For a design of trousers, the height was applied and the base angle was fixed. As a pattern drawing, using the height, a base angle and circumference of the hip, a trouser was designed. The production method for the pattern design is as follow: (1) The length formula, is height + $\frac{height}{2}$ (2) The hip girth formula is $\frac{hipgirth}{2}$ - $\frac{hipgirth}{20}$(3) A crotch angle is fixed at $72^{\circ}$. (4) The ratio of outer leg length to leg width is 5 : 8. (5) The component ratio of the upper outer leg length to the pant length is 5 : 8. (6) The ratio of the division point of front right inner leg length and left inner width to upper outer leg length is 5 : 8.

• 한국항공운항학회지
• /
• 제17권3호
• /
• pp.1-6
• /
• 2009

Since the success of the first flight, vast advancements have been made to the aircrafts with recent developments incorporating highly complex mechanisms, placing greater emphasis on the competence of the pilot. Studies are currently being undertaken to effectively source the trainee pilots with the most ideal level of aptitude for aviation with an aim to optimise the selection process with focus on economy and time, while research into identifying the optimal human characteristics for aviation is being done. As part of the selection process, number of tests is arranged with focus on the individual competence, suitability for flight, health status, aptitude and intelligence with the results of the tests used as reference materials during the selection procedure. This study has investigated the effect the academic competence has on the aptitude for aviation amongst many other abilities of human beings and the findings show that higher levels of aptitude have been demonstrated by the students who have displayed academic excellence across all the courses with statistics pointing to a positive correlation between the two subjects. This supports the theory that students who are academically superior have higher probability of being found to possess greater level of flight aptitude. The outcome of the study iterates the fact that academic competence of the students should not be regarded lightly in the selection process. Based on the current study, it is believed that a research into determining the relationship between the SAT results, average yearly grade and flight aptitude will help identify the key factors in possessing high level of flight aptitude with greater certainty.

• 한국제4기학회:학술대회논문집
• /
• 한국제4기학회 2004년도 추계학술대회
• /
• pp.37-43
• /
• 2004

The response of the CCCma coupled climate model to the imposition of LGM conditions is investigated. The global mean SAT and SST decrease by about $10^{\circ}C$ and $5.6^{\circ}C$ in the coupled model. Tropical SST decreases by $6.5^{\circ}C$, whereas CLIMAP reconstructions suggest that the tropics cool by only about $1.7^{\circ}C$, although the larger tropical cooling is consistent with the more recent proxy estimates. With the incorporation of a full ocean component, the coupled model gives a realistic spatial SST pattern, capturing features associated with ocean dynamics that are seen in the CLIMAP reconstructions. The larger decrease of the surface temperature in the model is associated with a reduction in global precipitation rate (about 15%). The tropical Pacific warm pool retreats to the west and a mean La $Ni\tilde{n}a$-like response is simulated with less precipitation over the central Pacific and more in the western tropical Pacific. The more arid ocean climate in the LGM results in an increase in SSS almost everywhere. This is particularly the case in the Arctic Ocean where large SSS increase is due to a decrease in river discharge to the Arctic Ocean associated with the accumulation of snow over the ice sheet, but in the North Atlantic by contrast SSS decreases markedly. This remarkable reduction of SSS in the North Atlantic is attributed to an increase in fresh water supply by an increase in discharges from the Mississippi and Amazon rivers and an increase in P-E over the North Atlantic ocean itself. The discharges increase in association with the wetter LGM climate south of the Laurentide ice sheet and in South America. The fresh water capping of the northern North Atlantic results in a marked reduction of deep convection and consequently a marked weakening of the North Atlantic overturning circulation. In the LGM, the maximum overturning stream function associated with the NADW formation decreases by about 60% relative to the control run, while in the Southern Ocean, oceanic convection is stronger in the LGM due to reduced stratification associated with an increase in SSS and a decrease in SST and the overturning stream function associated with the formation of AABW and the outflow increases substantially.

• 대한인간공학회지
• /
• 제25권4호
• /
• pp.81-90
• /
• 2006

Despite the government promoting women's participation in the engineering field, some statistics show that it has yet to be achieved. Potential reasons for this phenomenon include lower level of applications by women, or inherent gender gap in the professional field. Therefore, this study attempted to find impact of gender on college admission from the Lens Model perspective and Signal Detection Theory. This study consisted of three phases: identifying the necessary cues used in the admission process, analyzing existing data, and conducting two experiments to identify the effect of gender on admission decisions. Although the college application consisted of many cues, only five cues, school ranking, GPA, SAT score, resident status, and gender, were used to capture the officers' judgment policies for engineering admissions. Two experiments were conducted to investigate the impact of the gender factor in college admission. The enrollment officers first were presented with the existing data without the gender and asked to make dichotomous judgments. Secondly, the officers were asked to perform the judgment task with the gender cue present. Results showed that the gender did not play an important role in the judgments as expected. However, ideographical analyses on judgment strategies revealed that there were significant differences between the admission officers. Possible training implications are discussed.

• 한국지역사회생활과학회지
• /
• 제22권3호
• /
• pp.485-491
• /
• 2011

This study was to present the preferred and the suggested indoor temperature of college students in winter based on their body composition. A total of 14 subjects(6 males and 8 females) participated in this study. They sat in a climatic chamber controlled at $24^{\circ}C$ wearing experimental garments(0.7clo). The air temperature decreased $1^{\circ}C$ every 15 minutes until it reached $19^{\circ}C$. After the stepwise temperature change, subjects were asked to select a comfortable air temperature by dialing the temperature control switch inside the chamber. The preferred temperature was determined when subjects did not change the air temperature for 10 minutes. The measurements were oxygen consumption, rectal temperature, skin temperature, and subjective sensation. Main results are as follows. In a mild cold condition, females demonstrated lower oxygen consumption and mean skin temperature than males while keeping a constant rectal temperature. Females increased rectal temperature and decreased mean skin temperature greater than males from $24^{\circ}C$ to $19^{\circ}C$. Males showed larger oxygen consumption increase than females. It appears that the thermo-physiological responses in a mild cold condition might be different between males and females. The preferred winter indoor temperature was $22.3^{\circ}C$ for males and $23.4^{\circ}C$ for females, and the suggested temperature was $21^{\circ}C$ for males and $23^{\circ}C$ for females.