• 대한인간공학회지
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• 제16권1호
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• pp.15-27
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• 1997

The objectives of this study were twofold; (1) to determine an optimal handle size of a signal billy, based on the subjective assessment of grip comfort and (2) to investigate the relationship between hand anthropometry and the optimal handle size. Thirty-seven university male students were asked to rate seven cylindrical handles of different diameters in barehanded and gloved conditions, respectively. Among these handles, 3.5cm diameter of the handle size was found to be the most comfortable, in both bardhanded and gloved conditionsl. However, no statistically significant reduction in grip comfort occurred within handle diameter ranging from 2.5cm to 4.0cm. As the handle diameter was deivated from the range, grip discomfort in creased significantly. A Spearman rank correlation coefficient test revealed that hand anthropometries such as finger lengths, hand circumference, and hand thickness were statistically significant factors on the determination of the optimal handle size. The implications of these findings were discussed. The results of this study can be used as guidelines in designing the hand tools for power grip.

• 대한인간공학회지
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• 제26권3호
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• pp.59-65
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• 2007

In this study, six grip spans (45mm-65mm) were tested to evaluate the effects of handle grip span and user's hand size on maximum grip strength, individual finger force, and subjective ratings of comfort using a digital dynamometer with individual force sensors. Forty-six males were assigned into three hand size groups according to their hand lengths. Results showed that overall 55mm and 50mm grip spans were the most comfortable sizes and associated with the highest grip strength in the maximum grip force exertions, whereas 65mm grip span was rated as the least comfortable size as well as the lowest grip strength. In the interaction effect of grip span and hand size, small and middle hand sized participants rated the best preference and the least preference grip spans differently with large hand sized participants. With respect to the analysis of individual finger force, the middle finger force was the strongest and the highest contribution to the total finger force, followed by ring, index and little fingers. In addition, it was noted that each finger had a different optimal grip span for exerting maximum force resulting in a bowed contoured shaped handle for two-handle hand tools. Thus, the grip spans for two-handle hand tools might be designed according to the users' hand and finger anthropometrics to maximize performance and subjective perception of comfort.

• Communications for Statistical Applications and Methods
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• 제31권1호
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• pp.55-64
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• 2024

In this study, we consider the sample size determination problem for clustered count data with many zeros. In general, zero-inflated Poisson and binomial models are commonly used for zero-inflated data; however, in real data the assumptions that should be satisfied when using each model might be violated. We calculate the required sample size based on a discrete Weibull regression model that can handle both underdispersed and overdispersed data types. We use the Monte Carlo simulation to compute the required sample size. With our proposed method, a unified model with a low failure risk can be used to cope with the dispersed data type and handle data with many zeros, which appear in groups or clusters sharing a common variation source. A simulation study shows that our proposed method provides accurate results, revealing that the sample size is affected by the distribution skewness, covariance structure of covariates, and amount of zeros. We apply our method to the pancreas disorder length of the stay data collected from Western Australia.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.1043-1047
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• 2003

Most of the measurement and the evaluation of hand-transmitted vibration have been performed by using a small size single axis accelerometer between the handle and the hand palm or a three axis accelerometer attached on an adapter outside the hand(indirect measurement). It is most desirable for the correct evaluation of hand-transmitted vibration form the power tool handle to measure the acceleration between the handle surface and the hand palm in the three axis(direct measurement) as recommended in ISO 5349-1. In the study three axes acceleration measurement device was developed of which the thickness was less than 7mm so that it can be placed between the handle and the palm without any inconvenience during the measurement. To verify the performance of the developed device, measured acceleration by the two methods, direct and indirect, were compared in the study.

• 대한안전경영과학회지
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• 제8권1호
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• pp.43-52
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• 2006

The goal of this study is to investigate the ergonomic factors in designing or selecting the hand tool handle. Electromyogram (EMG) were measured for various wrist postures and handle sizes under two loading conditions. Anthropometric data were measured and the correlation with EMG measurement data were analyzed. Investigations of this study show that wrist posture should be neutral for minimum muscle tension and optimum handle size can be found by measuring the EMG measurement data. It show that hand width and EMG measurement data is greatly correlated also. This study can be a guide of designing or selecting a hand tool, but further study with large sample sizes and various groups is needed for making general conclusion.

• 대한인간공학회지
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• 제26권4호
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• pp.49-56
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• 2007

Handles on objects are very important to increase the safety and efficiency of manual handling of people who use them. In this study, four different prototype cartons combined with auxiliary handles were designed to determine the optimal handle position of cartons through the evaluation of user preferences. Twenty male students are participated in the experiment. Likert-5 point summated rating method was applied to evaluate the user preferences for provided handles of the carton among upper, middle, and lower position under the four different sizes and materials handling conditions(carrying positions). The results show that the subjects preferred upper part of the handle on the small cartons regardless of the carrying positions while upper and middle parts of the handle on the big cartons for handling above the waist height were preferred. An optimal handle position depending on the different sizes of carton and the different carrying positions were recommended based on the results of evaluation. It is thus recommended that the cartons provide handles on its relevant position depending on the size and materials handling condition to reduce the musculoskeletal stress and in turn to increase the user satisfaction.

• Communications for Statistical Applications and Methods
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• 제11권1호
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• pp.153-160
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• 2004

In recent years, the size of data set which we usually handle is enormous, so a lot of outliers could be included in data set. Therefore the robust procedures that automatically handle outliers become very importance issue. We consider the robust estimation problem of location parameter in the univariate case. In this paper, we propose a new method for defining robustness weights for the weighted mean based on the median distance of observations and compare its performance with several existing robust estimators by a simulation study. It turns out that the proposed method is very competitive.

• 디자인학연구
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• 제19권1호
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• pp.293-302
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• 2006

빠르고 복잡 다양한 생활 속에서 사용 가능한 공예품은 현대인에게 멋과 여유를 찾아준다. 바쁜 생활문화는 식습관을 변화 시켜 커피 전문점이 골목마다 생겨나고 있다. 이러한 시기는 도자 컵의 시장을 확대할 수 있는 좋은 기회라고 할 수 있다. 바쁘게 움직이며 사용하는 컵에서 또는 뜨거운 차를 마시기 위한 컵에서는 손잡이의 역할이 매우 중요하다. 손잡이는 컵을 들기 위해 제일 처음 만져지는 부분으로 편안한 촉감적인 경험에 의해 조형성과 어울려 컵의 아름다움을 배가시킬 수 있다. 그러나 한국역사에서 손잡이가 있는 고배가 나탄 것은 신라토기부터 이다. 하지만 이는 의기나 부장품인 경우가 대부분으로 한국의 차 문화에서 실제 손잡이가 있는 컵을 사용한 역사는 그리 길지 않다. 이와 같은 이유에서 아직까지는 컵 손잡이의 기능성보다는 조형성에 치중된 디자인이 주를 이루고 있다. 그러므로 컵의 손잡이를 연구 분석하여 인체공학 적으로 기능면에서 개선된 손잡이를 제작하기 위한 이론적 근거가 필요하다. 본 연구에서는 한국과 미국의 공방에서 생산되는 손잡이가 있는 도자 컵을 연구 분석하였다. 그리고 손잡이의 크기와 위치 등의 대등한 비교를 위해 한 가지 모양으로 컵을 정하고 손잡이의 굵기, 사용하는 손가락의 수, 손잡이 형태와 부착위치와의 관계, 손잡이 지지대의 효과, 손잡이 굵기의 변형, 컵의 무게중심과 손잡이의 관계 등을 변화요인으로 하여 시험하였고 사용자들에게 선호도 조사를 하고 분석하였다. 그 결과, 손잡이가 편하게 만들어지기 위해서는 손이 쉬고 있는 형태에 근접하도록 디자인하는 것이 중요하다는 것을 알았다. 즉 손의 크기, 손가락이 구부러지는 모양 등을 고려하고 컵의 무게 중심을 컨트롤 할 수 있는 위치를 찾고 여러 손가락이 손잡이 안쪽에 들어가서 컵의 무게를 분산시켜 편안하게 컵을 들 수 있도록 디자인해야 한다. 이때 엄지의 지지대가 있다면 같은 무게의 컵이라도 더욱 가볍게 들 수 있게 된다. 디자인상에서 컵의 손잡이를 몸체 방향으로 연장시키며 타원형을 그린다. 그 타원선상에 컵의 무게중심이 위치하고 있다면 컵의 손잡이는 효율적이라 할 수 있다. 이때 손잡이가 컵 몸체의 무게 중심과 가까울수록, 컵을 드는데 힘이 덜 든다고 볼 수 있다. 이렇게 디자인상에서 또는 컵의 제작 과정에서 효율적인 손잡이의 원리를 적용시킨다면 조형적인 면 뿐 아니라 기능적으로도 훌륭한 손잡이가 있는 컵을 제작할 수 있다.

• 산업공학
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• 제9권2호
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• pp.75-82
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• 1996

A scheduling system is developed for a parallel machine flow shop which reflects the situations of the manufacturing processes in the tire industry. The schedule is generated via simulation using heuristic rules to get satisfaction on such constraints as due dates, demands, work-in-process, process capacity, set-up times and scheduling speed. This system, constructed with relational DB, SQL and C language, consumes less than 10 minutes of PC simulation to handle real size problems.

• 대한의용생체공학회:의공학회지
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• 제16권4호
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• pp.481-491
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• 1995

Endovaginal and endorectal receiver only surface coils were designed for MR imaging (MRI) and $^1H$ MR spectroscopy (MRS) for the uterine cervix and the prostate. The shape of endovaginal coil wire was rectangular with round corner. Size of the coil wire was empirically determined for 7cm and 4cm along the long and short axis, respectively. The coil wire loop was supported by acryl handle and bent about $150^{\circ}$ at one side of the loop considering the average angle of the cervix to the vagina. We called this as a "spoon-type endovaginal coil". The wire of the endorectal coil was made of the flexible materials so that the wire loop became long elliptic shape by pushing the acryl handle into the plastic tube for the comfort of patients when the coil was inserted into the cervix. Then, the shape was maintained to be circle by popping out handle. Conventional spin echo (SE) and fast spin echo (FSE) sequences were used as 71 and 72 weighted imaging sequences, respectively. Matrix size was 128~$256{\times}256$. FOVs for surface coil and body coil were 14cm and 24cm, respectively. 3D volume localized in vivo $^1H$ MR spectroscopy of the human cervix and prostate was performed using PRESS or STEAM localization method with the following parameters . TR=3 sec, TE=135 msec for PRESS or 30 msec for STEAM, NEX=2, NS=48, Sl=2048, and SW=2500 Hz. Using home-built endovaginal and endorectal coils, excellent T1- and T2-images were obtained to visualize early cervical and prostate tumors. 3D volume localized in vivo IH MRS was useful to differentiate the cancerous tissue from the normal tissue.