• Korean Journal of Applied Biomechanics
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• v.17 no.4
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• pp.181-190
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• 2007

The purpose of this study was to analyze the muscle fatigue for lower limbs during the level and downhill running. The subjects were 6 males of twenties who have no experience to get the injury in the lower limbs and required to run on the level and downhill which was -7% grade treadmill at 8.3km/h. EMG signal was gained by ME3000P8 Measurement Unit and computed the Median Frequency(MF) with the power spectrum analysis in the Megawin software. Rectus femoris(RF), Vastus lateralis(VL), Gluteus medius(GLU), Biceps Femoris(BF), gastrocnemius medial head(GM), gastrocnemius lateral head(GL), Tibialis anterior(TA) were selected. The result of this study were as follows: The MF of RF decreased in the downhill running than level running in length of time but, the MF of VL was opposite. The MF of BF decreased in the level and downhill running, but, the MF of BF decreased much in the level than downhill running. The MF of GLU decreased much in the downhill running but, almost no change in the level running. The MF of TA decreased in the level running than downhill running. The MF of GL decreased in the level running but, the MF of GM decreased in the downhill running in length of time. This study analyzed the muscle fatigue of the lower limbs with the median frequency on the basis of an assumption that the impact force for the flexion and extension of the joint and the body mass may be much in the eccentric contraction such as the downhill running than level running. RF and GM showed the muscle fatigue in the downhill running than level running. BF and GL showed the muscle fatigue in the level running than downhill running.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.3
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• pp.359-364
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• 2013

In order to use a linear vibration motor for the actuator of a haptic interface, the motor must provide a higher reaction rate and longer service life than typical rotational motors with an eccentric mass. In this paper, we propose a linear vibration motor that is equipped with a voice-coil actuator and permanent-magnet springs. To concentrate the magnetic flux in the actuator, a Halbach-style magnetization pattern is used. Permanent-magnet springs replace mechanical springs to help increase the service life. We use the method of equivalent current sheets and the method of images to analyze and model the proposed vibration motor. These methods are validated using finite element analyses and experiments. A prototype motor is designed and fabricated. Tests with the prototype show the feasibility of the proposed linear vibration motor.

• Journal of Korean Society of Steel Construction
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• v.14 no.4
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• pp.471-479
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• 2002

In this paper, 18 square CFT columns filled with high-strength concrete were tested under concentric or eccentric axial loading. Two parameters of the experimental program included the buckling length-section depth ratio ($L_K$/D) and the eccentricity of the appled compressive load (e). In additon, mechanical properties such as the compressive concrete strength and compressive and tensile steel strength were measured and incorporated into the material models for the stress-strain relationships of concrete and steel. This model was used in an elasto-plastic analysis in order to predict the behavior of the slender CFT columns. Observtions of the failure mode during the tests under axial loadig were also presented. The strengths obtained from the analysis. Recommendations for Design, and Constructions of CFT structures were presented, as verified by the experimental results.

• Journal of Korean Society of Steel Construction
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• v.16 no.5 s.72
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• pp.529-541
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• 2004

Concrete filled steel tube structures were recently used in constructing high-rise buildings due to their effectiveness. Studies on concrete filled steel tubes have been focused on the experiments of uni-axial compression and bending and eccentric compression. There were also a few studies that investigated CFT member behavior under combined compression and torsion. The behavior of a circular CFT column under combined torsion and compression was theoretically investigated, considering the confinement of steel tubes on the concrete, the softening of the concrete, and the spiral effect, which were the dominant factors that influenced compression and torsion strength. The biaxial stress effects due to diagonal cracking were also taken into account. By applying those factors to compatibility and equilibrium conditions, the basic equation was derived, and the equation could be used to incorporate the torsional behavior of the entire loading history of the CFT member.

• Korean Journal of Veterinary Research
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• v.39 no.1
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• pp.169-176
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• 1999

The purposes of this study were to set up the method of the natural killer(NK) cell activity assay using the flow cytometer and to examine the characteristics and distribution of the NK cell during rat hepatocarcinogenesis. Forty five male 6 week-old specific pathogen free(SPF) Sprague-Dawley rats were randomly divided into three groups. Group I was the non-treated control and given normal diet and water. Group II was treated with diethylnitrosamine(DEN, 200mg/kg, i.p.) and partial hepatectomy. Group III was treated with DEN, partial hepatectomy and 0.05% phenobarbital sodium in water from 3 to 16 weeks. All animals were examined the morphology of the large granular lymphocyte(LGL), the LGL percent of the total lymphocytes and the LGL conjugation rate with YAC-1 cell in peripheral blood, spleen and liver. Moreover, activity of the LGL isolated from peripheral blood lymphocytes was determined using the flow cytometer. As results, LGL were observed in the peripheral blood, spleen and liver. LGL were observed the relatively faintly staining basophilic cytoplasm with granules, and eccentric, often kidney-shaped nuclei in Giemsa stain. Its size was $11{\sim}13{\mu}m$. LGL percentage of the isolated lymphocytes in peripheral blood, spleen and liver were 1.8~2.3%, 1.3~1.4% and 0.87~0.99%, respectively. LGL conjugation rate with YAC-1 cell was shown to be peripheral blood(9.3~10.3 %) > spleen(7.7~8.7%) > liver(5.6~7.0%). The activity of the LGL isolated from peripheral blood lymphocytes in Group I, II and III was 33.7%, 30.5% and 35.4%, respectively. However, all values were not significantly between groups.

• Journal of fish pathology
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• v.11 no.1
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• pp.69-76
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• 1998

An apicomplexan parasite, Perkinsus sp. was observed from the cultured baby clams, Ruditapes philippinarum, collected from the coast of Kochang and Taean (South Korea), where it caused seasonal mortality of clams. Several milky-white cysts were observed on the surface of gill and visceral mass of parasitised clams. The trophozoites of parasite had eccentric nucleus and proliferated by schizogony in gill, mantle, hepatopancrease and reproductive tissues, resulting in the formation of granuloma and the intensive infiltration of hemocytes in the tissues. During incubation in FTM, trophozoites increased in size, resulting in prezoosporangia which appeared as round black spheres when colored with Lugols iodine solution. The prevalence of Perkinsus sp. in clams was Kochang, 73.1%; Taean, 94.8% (during 9-mo. survey) and showed size-dependent infection. Hemacolor kit was useful to reduce time for diagnosis of the trophozoite of Perkinsus sp. that has been responsible of massive motalities in the clam.

• Journal of the Korean Society of Safety
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• v.21 no.1 s.73
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• pp.96-104
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• 2006

This study is to find out how the sawdust-mixed RC beam with holes acts compared to two case of normal one with sawdust without hole, without sawdust. variables are ED3H1, ED3H2, ED3H1UB, ED3H2L, ED5H1, ED5H1UB, ED5H2, ED5H2L, Normal with sawdust PLA without sawdust. All sand, aggregate, cement are in accordance with KS. mixing design is also in accordance with KS and done at D remicon company in order to decrease any error in mixing manually. ED3H1 showed 7tone of maximum load capacity having only minor tensile deformation around hole, compared to the center of the beam. ED5H2L showed almost same shape of tensile strain between hole area and center of two beam length, while having 9.5 tone load capacity, incase of two holes being in the longitudinal axis. But ED5H2 in case of two holes being in same forcing direction showed 8.4tone of load capacity while having minor tensile chape around hole and normal tensile shape in the center of beam length. Two diameter 3cm hole in longitudinal axis give more effective behavior than the other case, practically. Capacity decrease between 5cm and 3cm in eccentric position form the longitudinal axis is less than percents. There is minor capacity difference between hole diameter 3cm hole, but 13tone difference of load capacity between hole diameter 5cm.

• Journal of the Korean Society of Safety
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• v.21 no.2 s.74
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• pp.70-79
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• 2006

many plumbing system are needed in the ceiling of the building as it becomes advanced more and more. This leads to make effective space between ceiling level and slab less. Also, piping system is not suitably arranged and operated if it is bent around the columns which they are a lot. But this system can be more effective if it passes through the columns directly. Most people think that those columns should not be damaged with such as holes. But actually this is existed in a hotel building in switzerland. This study is to fing out how much capacity the columns become damaged and low using model size of $20cm{\times}30cm$ rectangular section, and 160cm long, in the structural test. it's compressive strength is focused on $240kg/cm^{2}$ design strength, commonly used in korea. Compressive test for them was done at Hanyang University using UTM one thousand tone(1000t) capacity. Variable numbers for the study are one hole of dia 3cm with distance 20cm or 40cm, two holes of dia 3cm with 20cm and 40cm distance, one hole of dia 5cm with distance 20cm and 40cm, two holes of dia 5cm with 20cm and 40cm distance, me eccentric hole with 20cm and 40cm distance, Normal(without hole). two test specimens of each variable are made for the test. ED5H20 capacity was 16.7% decreased, compared to normal one. While ED5H40 distant 40cm from the end of column top showed 19.5% capacity decrease, compared to normal one. Strain of ED5H20 diameter 5cm, in distance of 20cm form the top of the column was less 5% than the one of diameter 3cm. Finally, conclusions are that in case of hole diameter 3cm, located at 20cm from the end of the column top, capacity was decreased down to 3, percent only compared to the same diameter hole with 20cm distant from the end of it.

• The Korean Journal of Cytopathology
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• v.2 no.2
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• pp.153-159
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• 1991

Langerhans' cell histiocytosis (LCH), known for histiocytosis X, is a clinicopathologic entity characterized by proliferation of Langerhans' cells (LCs) throughout the body including the reticuloendothelial system, bone, and skin. LCs is currently considered as a distinct type of histlocytic cells, not primarily phagocytic in nature. Recently, we could make the diagnosis on cytologic specimen in a 3 month-old-boy and a 3 year-old-boy. The cases were diagnosed on scraping smear from the skin and fine needle aspiration cytology from the lymph node, respectively. The characteristic cytologic features of Langerhans' cells were noted in the nuclei, namely eccentric, indented, elongated, and grooved nuclei. The cells also had abundant and acidophilic cytoplasm. The cytologic diagnoses were confirmed on the biopsies from the skin and lymph node, respectively.

• The Korean Journal of Cytopathology
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• v.17 no.1
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• pp.51-55
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• 2006

The plasmacytoid variant is an extremely rare form of urothelial carcinoma in which the malignant cells resemble those of plasmacytoma. We report the cytologic features of 3 cases of this disorder. All 3 patients were male and presented with painless macroscopic hematuria. The voided urine cytology revealed a few scattered clusters of tumor cells in a bloody background. Each tumor cell had an abundant amount of cytoplasm that was clear or densely stained and characterized by eccentrically located nuclei. A histological examination of tissue obtained from a radical cystectomy confirmed the cytologic diagnosis in each 3 case, revealing a diffusely infiltrating tumor composed of round, noncohesive tumor cells demonstrating a high nuclear grade. These cells had infiltrated the tunica propria in 2 cases, but were limited to the submucosa in 1 case. The tumor cells were plasmacytoid in appearance, each demonstrating an eccentric nucleus and dense cytoplasm, as seen in the cytologic findings. All of the tumors were immunoreactive for pancytokeratin, CK7, CK20; negative for epithelial membrane antigen (EMA), leukocyte common antigen (LCA), kappa, lambda, and CD79a. Thus, it is important to consider the plasmacytoid variant of urothelial carcinoma in addition to plasmacytoma or lymphoma as a diagnosis when encountering plasmacytoid tumor cells in a voided urine sample.