• Journal of the Korean Society of Costume
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• v.53 no.4
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• pp.87-99
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• 2003

The measurement in ruling period of King Sejong in Chosun Dynasty remained unchanged compared with that of Goyeo Dynasty. But Hwangjongchuck, the basis of measurement was amended in the 7th year in ruling period of King Sejong, Juchuck, Youngchochuck, Cholegichuck in the 12th, and Pobeckchuck in the 13th. The record of Pobeckchuck first appeared in the true record of Chosun Dynasty in the 4th year in ruling period of Sejong, and first record on the amendment of the Pobeckchuck was found in the 13th year in his ruling period. The presentation of the comparison of Pobeckchuck with Cholegichuck in volume 128 of true record of Sejong makes help the estimation of the length of Pobeckchuck. To calculate one Chuck of Pobeckchuck with this measurement comes to 44.75cm in present measurement, and the length at this time had remained unchanged to Yeonsangun period. Important fact which was newly found in the true record of Chosun Dynasty was that Pobeckchuck had been used for diverse purposes. Pobeckchuck was used to measure width, length and thickness in manufacturing wardrobe. and also to measure cloth decorating wardrobe. This is the first record(4th year of reign of Sejong) showing that Pobeckchuck was first used to measure cloth in Chosun Dynasty The record shows that Pobeckchuck was also used to measure the length of circumference of castle for its construction. to measure distances between people, the length of hook of wooden handle, and the height of man.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.623-629
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• 2002

The spectrum of impulse response signal from an impulse hammer testing is widely used to obtain frequency response function(FRF) of the structure. However the FRFs obtained from impact hammer testing have not only leakage errors but also finite record length errors when the record length for the signal processing is not sufficiently long. The errors cannot be removed with the conventional signal analyzer which treats the signals as if they are always steady and periodic. Since the response signals generated by the impact hammer are transient and have damping, they are undoubtedly non-periodic. It is inevitable that the signals be acquired for limited recording time, which causes the finite record length error and the leakage error. In this paper, the errors in the frequency response function of multi degree of freedom system are formulated theoretically. And the method to remove these errors is also suggested. This method is based on the optimization technique. A numerical example of 3-dof model shows the validity of the proposed method.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.10
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• pp.792-798
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• 2002

The spectrum of impulse response signal from an impulse hammer testing is widely used to obtain frequency response function (FRF) of the structure. However the FRFs obtained from impact hammer testing have not only leakage errors but also finite record length errors when the record length for the signal processing is not sufficiently long. The errors cannot be removed with the conventional signal analyzer which treats the signals as if they are always steady and periodic. Since the response signals generated by the impact hammer are transient and have damping, they are undoubtedly non-periodic. It is inevitable that the signals be acquired for limited recording time, which causes the finite record length error and the leakage error. In this paper, the errors in the frequency response function of multi degree of freedom system are formulated theoretically. And the method to remove these errors is also suggested. This method is based on the optimization technique. A numerical example of 3-dof model shows the validity of the proposed method.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.363.2-363
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• 2002

The spectrum of impulse response signal from an impulse hammer testing is widely used to obtain frequency response function(FRF) of the structure. However the FRFs obtained from impact hammer testing have not only leakage errors but also finite record length errors when the record length for the signal processing is not sufficiently long. The errors cannot be removed with the conventional signal analyzer which treats the signals as if they are always steady and periodic. (omitted)

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.9
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• pp.702-708
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• 2002

The spectrum of impulse response signal from an impulse hammer testing is widely used to obtain frequency response function(FRF). However the FRFs obtained from impact hammer testing have not only leakage errors but also finite record length errors when the record length for the signal processing is not sufficiently long. The errors cannot be removed with the conventional signal analyzer which treats the signals as if they are always steady and periodic. Since the response signals generated by the impact hammer are transient and have damping, they are undoubtedly non-periodic. It is inevitable that the signals be acquired for limited recording time, which causes the errors. This paper makes clear the relation between the errors of FRF and the length of recording time. A new method is suggested to reduce the errors of FRF in this paper. Several numerical examples for 1-dof model are carried out to show the property of the errors and the validity of the proposed method.

• Fisheries and Aquatic Sciences
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• v.17 no.4
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• pp.491-496
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• 2014

A total of six specimens (57.03-100.72 mm in standard length) belonging to the family Diodontidae were collected around Jeju Island, Korea between July and August 2013. On the Basis of morphological and molecular analyses, we identified the specimens as Cyclichthys orbicularis (Bloch, 1785), a new record to the Korean fish fauna. Morphologically, the species is characterized by nine caudal fin rays, immovable spines on the head and body except the caudal peduncle, and small black spots dorsally. Some morphometric characters changed disproportionately with growth, which was a new finding. Caudal peduncle length, body width and preanus length to standard length tend to grow at a rate different from that of overall growth. When the 601 base pairs of mitochondrial DNA cytochrome c oxidase subunit I sequences of our specimens were compared with those of other diodontid fishes, our specimens clustered tightly around C. orbicularis (d = 0.000-0.002) in an NJ tree, with a high bootstrap value (99%). We herein describe the morphological and molecular traits of the specimens, and propose a new Korean name, "gud-ga-si-bok-sok" for the genus Cyclichthys, and "dung-geun-gud-ga-si-bok" for C. orbicularis.

• Ocean and Polar Research
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• v.42 no.4
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• pp.283-292
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• 2020

Oncaea prendeli Shmeleva, 1966 is redescribed here based on a specimen collected using a fine-mesh net in the epipelagic layer in the south sea of Jeju Island, Korea. The Korean specimen is generally similar to Mediterranean specimens in terms of morphological characteristics, but it shows a few minor differences in a slightly larger length-to-width ratio for the distal endopod segment of the antenna, a relatively shorter caudal seta IV, and additional ornamentation on the maxillule and maxilla. This species is distinguishable from the most similar congeneric species, O. tregoubovi Shmeleva, 1968, and three species of the genus Spinoncaea Böttger-Schnack, 2003 by the distal and lateral armature of the antenna, ornamentation on the female maxilliped, spine number on the endopod of leg 2, and proportional length of setae on the caudal ramus. Moreover, spine lengths on the exopods of legs 2-4 are proposed as new morphological characters for the identification of congeners. This is the first record of O. prendeli in Korean waters.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1995.10a
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• pp.80-85
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• 1995

Too see the effects of finite record on the estimation of WVD in practice, a window which has time varying length is examined. Its length increases linearly with time in the first half of the record, and decreases from the center of the record. The bias error due to this window decreases inversely proportionally to the window length as time increases in the first half. In the second half, the bias error increases and the resolution decreases as time increases. The bias error due to the smoothing of WVD, which is obtained by two-dimensional convolution of the true WVD and the smoothing window, which has fixed lengths along time and frequency axes, is derived for arbitrary smoothing window function. In the case of using a Gaussian window as a smoothing window, the bias error is found to be expressed as an infinite summation of differential operators. It is demonstrated that the derived formula is well applicable to the continuous WVD, but when WVD has some discontinuities, it shows the trend of the error. This is a consequence of the assumption of the derivation, that is the continuity of WVD. For windows other than Gaussian window, the derived equation is shown to be well applicable for the prediction of the bias error.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.71-77
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• 2002

The spectrum of impulse response signal which is obtained from an impulse hammer testing is used for frequency response function, nevertheless it has serious faults when the record length for the signal processing is not very long. The faults cannot be avoided with the conventional signal analyzer that is processing all the signals as if they are always periodic. The signals generated by the impact hammer are undoubtedly non-periodic because of the damping, and are acquired for limited recording time due to the memory as well as the computation performance of the signal analyzer. This paper will make clear the relation between the faults and the length of recording time, and propose the way for solving the faults.

• Ocean and Polar Research
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• v.30 no.3
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• pp.347-349
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• 2008

A single juvenile of the jawfish Stalix toyoshio (24.0 mm standard length) was collected from the South Sea of Korea at a depth of 135 m during box-corer sampling. The specimen was characterized by the absence of stripes on both the body and vertical fins, well-developed cephalic pore systems, yellowish body and fins, six transversely-forked dorsal fin spines, and five mandibular pores. Here, we describe the specimen, which represents the first record of S. toyoshio from Korea and the second record from the northwestern Pacific.