• Journal of Fashion Business
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• v.25 no.4
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• pp.36-60
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• 2021

This study aimed to provide basic data for establishing a sizing system for menswear by investigating body size changes and body shapes in adult men in their 30s to 50s. Data on 52 different upper body categories collected from 4,314 people during the 5-7th Size Korea surveys were analyzed. The waist height, hip height, torso and arm lengths, and torso and upper limb circumferences increased while the arm joint sizes decreased. According to factor analysis, factors 1 and 2 referred to 'the horizontal size of the upper body and limbs' and the 'torso height and upper limb length', respectively, while factors 3 and 4 represented 'shoulder size' and 'upper body length' respectively. In clustering analysis, types 1 and 2 were 'short and fat' and 'tall and thin,' respectively, while types 3 and 4 represented 'tallest and chubby' and 'shortest and small' respectively. Torso length increased in the 30 to 40s in type 1 while torso circumference increased in the 30s and late 40s in type 2. In type 3, shoulders got bigger in the 30s. In type 4, torso circumference increased in the early 30s, and torso length increased in the late 40s. 'Thin' was a typical body shape in the early 30s. Among early 40s men, distribution evolved from 'small' to 'thin.' In the late 40s, while the percentage of 'small' decreased, the ratio of 'obese' increased. In the 50s, 'small' was the most common.

• Journal of Power Electronics
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• v.17 no.1
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• pp.96-105
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• 2017

In this paper, a hybrid modular multilevel converter (MMC) topology with an improved nearest level modulation method is proposed for medium-voltage high-power applications. The arm of the proposed topology contains N series connected half-bridge submodules (HBSMs), one full-bridge submodule (FBSM) and an inductor. By exploiting the FBSM, half-level voltages are obtained in the arm voltages. Therefore, an output voltage with a 2N+1 level number can be generated. Moreover, the total level number of the inserted submodules (SMs) is a constant. Thus, there is no pulse voltage across the arm inductors, and the SM capacitor voltage is rated. With the proposed voltage balancing method, the capacitor voltage of the HBSM is twice the voltage of the FBSM, and each IGBT of the FBSM has a relatively low switching frequency and an equalized conduction loss. The capacitor voltage balancing methods of the two kinds of SMs are implemented independently. As a result, the switching frequency of the HBSM is not increased compared to the conventional MMC. In addition, according to a theoretical calculation of the total harmonic distortion of the electromotive force (EMF), the voltage quality with the presented method can be significantly enhanced when the SM number is relatively small. Simulation and experimental results obtained with a MMC-based inverter verify the validity of the developed method.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.9
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• pp.74-81
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• 2002

Recently tube hydroforming has been widely applied to the automotive industries due to its several advantages over conventional methods. In this paper, attention is paid to comparison of an implicit and an explicit finite element method widely used for numerical simulation of a hydroforming process. For an explicit FEM, a huge amount of computational time is required because of the very small time increment to solve a quasi-static problem. Hence, when an explicit FEM is used fDr a hydroforming process, it is general to convert the real problem to a virtual problem with a different processing time and mass density by appropriate scaling factor. However it is difficult to figure out how large the scaling should be adopted enough to ignore the dynamic effects and maintain the desired accuracy. In this paper, the comparison of the results obtained from both methods focus on the accuracy of the predicted geometrical shape and the stress with various scaling factors which are applied to analyze hydroforming process of an automobile lower arm.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.126-129
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• 2010

MEMS(micro electro-mechanical systems) inertial switch which is applicable to the ignition Safe-Arm- Unit of propulsion system is devised. The MEMS inertial switch is designed according to the general design procedure for conventional mechanical elements. Unlikely conventional MEMS accelerometer, threshold inertial switching mechanism is adopted which makes a MEMS element an abrupt switching in a certain acceleration level. By comparing the design data and test results of the specimen a small discrepancy in switching acceleration level is found which is presumably due to the nonlinear characteristics of the beam spring and the flexure hinge which are the main parts of the MEMS inertial switch.

• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.2
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• pp.176-183
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• 2024

Assessing the stability of small fishing vessels is important to prevent capsize accidents in coastal waters that primarily occur on small fishing vessels. However, the regulations regarding stability assessment for small vessels under 24 m are inadequate according to the domestic Fisheries Act. Based on safety standards issued by the Ministry of Oceans and Fisheries in 2022 to enhance safety and welfare, vessels adhering to the enhanced safety standards for standard ship types are required to establish stability regardless of their length. This study aims to utilize these aforementioned standards to assess the stability of vessels under 24 m, investigating the suitability of applying these criteria to these vessels and examining the impact on various small vessels with different superstructures. Initially, a 4.99-ton fishing vessel designed according to the standard ship type was selected as the subject vessel. Compliance with the standards was evaluated based on the initial stability of the vessel using the transverse metacentric height (GM) and transverse restoring moment arm at the limit angle (GZ_α). Additionally, six types of small vessels with identical hull forms and specifications to the subject vessel were further examined using prevalent superstructure designs in small fishing vessels. The stability of the subject small vessel was also assessed. A study of a 4.99-ton standard fishing vessel confirmed that the safety standards for standard fishing vessels with enhanced safety welfare were applicable to small fishing vessels under 4.99-ton class and that the stability of small fishing vessels with superstructure modifications was not significantly changed.

• The Korean Journal of Cytopathology
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• v.4 no.1
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• pp.45-51
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• 1993

A 30-year-old woman who was diagnosed as peripheral neuroblastoma by fine needle aspiration of a soft mass of the right upper arm is described. She presented a slowly growing, soft mass of the right upper arm for 1 month. The right humerus revealed no abnormal finding on X-ray. Ultrasonogram of the right upper arm revealed a well demarcated, smooth marginated solid mass without invasion of adjacent structures. Fine needle aspiration was done under the impression of soft tissue tumor with undetermined biologic behavior. The aspirates were highly cellular and the tumor cells were dispersed both singly and in clusters of varying size. The clusters occasionally showed a central capillary core and rosette-like structures. The tumor cells were small in size and had a small to medium amount of cytoplasm. Some of them revealed slender cytoplasmic processes. The nuclei showed distinct nuclear membranes, finely clumped chromatin and small conspicuous nucleoli. Cellular pleomorphism or mitotic figure was not definite. These cytologic findings were interpreted as a malignant, non-lymphomatous small round cell tumor, most likely representing peripheral neuroblastoma or Ewing's sarcoma. Final diagnosis was confirmed by simple excision as peripheral neuroblastoma.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.813-816
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• 1991

Direct-drive SCARA-type industrial robots are increasingly used in the assembly process of small mechanical parts as well as electronic components, which uses direct-drive (DD) motors instead of reduction gear-type conventional motors for the actuators of manipulator arms. There are many advantages in using DD motors for robots, such as no backlash, low friction, high mechanical stiffness capability for fast and precise arm control, and high repeatability of positioning. However, there exist a number of difficulties which must be overcome to ensure proper construction and operation; increasing effects of load veriation and nonlinear and coupling dynamics, severe vibration caused by resonance of the manipulator components and low mechanical damping, etc. In order to handle these difficulties, lots of efforts have been made such as reduction of the arm inertia and elimination of the resonance, Performance evaluation of a recently developed, domestic DD robot shows that it works excellently compared with conventional robots. It, however, requires proved reliability and price competitiveness against its foreign counterparts.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.1052-1057
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• 1993

A scara type Direct Drive Arm(DDA) with two degrees-of-freedom is designed and implemented. The direct drive motor is used to furnish large torque to reduce the modeling error by the gear and chains. To control the DDA, a multiprocessor control structure with multirate dynamic control algorithm is designed. In the control algorithm, the dynamics of system is used to calculate the nominal control torque and the feedback controls are calculated with a parallel processing algorithm for each joint. The laboratory experiments on Hong-Ik DDA by dynamic control algorithm are presented and compared to that of PID control algorithm. This result shows that the proposed controller guarantees small trajectory error and stability. With this research, Hong-Ik DDA is expected to be utilized as A basic tool for robotics and control engineering.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.04a
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• pp.234-238
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• 2001

A lot of researches have been done in teleoperation field. For accurate and reliable teleoperation, force reflection is required so that the master can feel the same force, which is measured at reflection have been applied to most of the master device. Therefore the master can not control the force exerted by the slave robot to the environment. But some tasks such as an insertion with very small tolerance, skewing bolt and so forth, require the force command from the master.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.04a
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• pp.127-132
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• 1992

To relize the future intelligent robot the development of a special-purpose processor for a coordinate transformation is evidently challenging task. In this case the complexity of a hardware architecture strongly depends on the adopted algorithm. In this paper we have used an inverse kinemetics algorithm based on incremental unit computation method. This method considers the 3-axis articulated robot as the combination of two types of a 2-axis robot: polar robot and 2-axis planar articulated one. For each robot incremental units in the joint and Cartesian spaces are defined. With this approach the calculation of the inverse Jacobian matrix can be realized through a simple combinational logic gate. Futhermore, the incremental computation of the DDA integrator can be used to solve the direct kinematics. We have also designed a hardware architecture to implement the proposed algorithm. The architecture consists of serveral simple unitsl. The operative unit comprises several basic operators and simple data path with a small bit-length. The hardware architecture is realized byusing the EPLD. For the straight-line motion of the KAIST arm we have obtained maximum end effector's speed of 12.6 m/sec by adopting system clock of 8 MHz.