• 수산해양기술연구
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• 제60권3호
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• pp.235-243
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• 2024

Researching and estimating the ecological characteristics of target fish species is crucial for fisheries resource management. The results of these estimates significantly influence stock assessments and management reference points such as size limit and closed seasons. Recently, ecological characteristics have been changing due to overfishing, climate change, and marine pollution, making continuous estimation and monitoring essential. This study analyzed the ecological changes in small yellow croaker (Larimichthys polyactis) resources in Korea over 24 years (2000-2023) using biological data (growth and gonad traits). By estimating the annual length-weight relationship and length at maturity (L50 and L95), we interpreted the numerical trends of early maturation due to resource depletion. The parameter b of the length-weight relationship, indicating the nutritional status of the resources, showed a slight increase over the years, suggesting relatively good nutritional status (b > 3.0) during most periods. Trend analysis between length at maturity and biomass indicated that as biomass decreased, maturity length also decreased.

• Journal of the Korean Data and Information Science Society
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• 제28권4호
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• pp.889-898
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• 2017

In this research multiple change-points estimation for South Korean electricity generation data is considered. We analyze the South Korean electricity data via deterministically trending dynamic time series model with multiple structural changes in trends in a Bayesian approach. The number of change-points and the timing are unknown. The goal is to find the best model with the appropriate number of change-points and the length of the segments. A genetic algorithm is implemented to solve this optimization problem with a variable dimension of parameters. We estimate the structural change-points for South Korean electricity generation data and Nile River flow data additionally.

• 한국의류산업학회지
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• 제19권5호
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• pp.589-594
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• 2017

The purpose of this study is to provide basic data for design and pattern development research in the modernization of Cheollik by comparing and analyzing the interrelationships between the components of the Cheollik. The 237 pieces of excavated costume Cheollik in the museums were surveyed. The size of the Cheollik components were examined by 100 year unit from 1400s to after 1800s. In the 1400s, the length of Cheollik was the shortest and the length of top was longer than the bottom. In the 1700s, the total length was the longest and the bottom was longer than the top. As the age increases, the total length and the bottom become longer and the length of the top becomes shorter. Poom and Gutseop were the largest in the 1400s and the smallest the after 1800s. As the age of the Poom and Gutseop decreased, the width of the Anseop increased. Gutseop was always present but Anseop was not always present in Cheollik components. As the ages passed, Jindong and Soogu became narrower and Baerae became wider. These change of Cheollik's sleeves form were affected by GongBok(so-called official wear) sleeves. By age, Cheollik did not show any big change in the basic shape, but the partial dimensions of the components showed changes. If the design and pattern research for modernization is done based on systematic establishment of pattern dimension of Cheollik, Cheollik dress combines practicality while preserving beauty and tradition at the same time.

• 복식
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• 제32권
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• pp.21-30
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• 1997

Chogori the basic upper garment of korea costume occupies an important role in tra-ditional dressing and continues to be in use to the present days. Of course there has been changes in the length and line of Chogori with the flow of time based on the Ancient Yoo. This is a study of the 14 parts of Chgori based on statistical analysis by computing the practical measuements. Here the statistical analysis is a objective and quantitative of the stylistic changes in Chogori with time. In this study from the data the Mean and Standard deviation has been evaluated and periodic change is shown by graph to test the periodic change T-test Regressional analysis Index analysis has been used. The results are as follows: 1. The length of clothing has changed with time except the sleeve length. Here the length of clothing means all the other measurements ex-cept the sleeve Thus while the measurements of sleeve length has been uniquely unchanged the other measurements have influenced each other. 2. Generally the form of Chogori had the tendency towards smallness in the 19th cen-tury. But it tended to get larger in the 20th century. 3. Compared to other periods the mode of 19th and 20th century Chogori was widely ac-cepted as the Standard deviation of that period was very narrow. 4. The results seen from the regressional analysis of the Cho-sun period woman's Chogori satisfy the t-value and R-squared and thus support the regression formula presump-tion. 5. From the index analysis it is revealed that with decrease in the armhole measurement sleeve measurement and neckband; relatively same decrease in the wrist measurement; and very marked decrease in the sideline measurement.

• 대기
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• 제26권1호
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• pp.111-126
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• 2016

In the numerical weather model, surface properties can be defined by various parameters such as terrain height, landuse, surface albedo, soil moisture, surface emissivity, roughness length and so on. And these parameters need to be improved in the Seoul metropolitan area that established high-rise and complex buildings by urbanization at a recent time. The surface roughness length map is developed from digital elevation model (DEM) and it is implemented to the high-resolution numerical weather (WISE-WRF) model. Simulated results from WISE-WRF model are analyzed the relationship between meteorological variables to changes in the surface roughness length. Friction speed and wind speed are improved with various surface roughness in urban, these variables affected to temperature and relative humidity and hence the surface roughness length will affect to the precipitation and Planetary Boundary Layer (PBL) height. When surface variables by the WISE-WRF model are validated with Automatic Weather System (AWS) observations, NEW experiment is able to simulate more accurate than ORG experiment in temperature and wind speed. Especially, wind speed is overestimated over $2.5m\;s^{-1}$ on some AWS stations in Seoul and surrounding area but it improved with positive correlation and Root Mean Square Error (RMSE) below $2.5m\;s^{-1}$ in whole area. There are close relationship between surface roughness length and wind speed, and the change of surface variables lead to the change of location and duration of precipitation. As a result, the accuracy of WISE-WRF model is improved with the new surface roughness length retrieved from DEM, and its surface roughness length is important role in the high-resolution WISE-WRF model. By the way, the result in this study need various validation from retrieved the surface roughness length to numerical weather model simulations with observation data.

• Korean Journal of Acupuncture
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• 제25권4호
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• pp.49-58
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• 2008

Objectives and Methods : The present study was to investigate the change of acupuncture point location of gallbladder meridian in head by way of reviewing classical literatures. Result and Conclusions : 1. The locations of acupuncture points closed-by anatomical marks such as GB1, GB2, GB3, GB11, GB12, GB19, GB20 are clear and accurate. 2. The expression of acupuncture points' locations of GB4, GB5, GB6, GB8 and GB10 are obscure in classical literature, but their locations became clear and objective in recent literatures. 3. The locations of GB9 and GB13 are open to dispute but WHO standard acupuncture point seems to be resonable. 4. In classical literature, the length from the midpoint of the anterior hairline to the midpoint of the posterior hairline is 12 B-cun, and the length from the midpoint of the anterior hairline to the GB19 is 5 cun, 5.5 cun or 6.5 cun. We presume that the length from GB15 to GB19 might have been measured by F-cun.

• 대한치과보철학회지
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• 제29권1호
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• pp.281-287
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• 1991

This study was designed to investigate the influence of the clasp arm length on the change of retentive force with repeated placement or removal. The author measured the retentive force of Akers clasp and I-bar clasp in the depth of undercut 0.5mm, 0.25mm, respectively, varying the length of clasp arm, that is, 10mm, 14mm, 17mm in Akers clasp and 16mm, 18mm, 20mm in I-bar clasp. The retentive force was measured just before the placement of removal, after 100 times repeated placement or removal, after 300 times repeated placement or removal. The obtained results were as follows : 1. The shorter the clasp arm, the greater retention in Akers clasp and I-bar clasp(p<0.05). 2. There was decreased retentive force of Akers clasp and I-bar clasp after 300 times repeated placement or removal(p.<0.005). 3. The decreasing rate of retentive force in Akers clasp with 10mm was higher than that with 17mm, after 300 times repeated placement or removal, but there was no statistica difference(p>0.05).

• 한국전기전자재료학회논문지
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• 제24권11호
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• pp.865-869
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• 2011

A cantilever-type piezoelectric generator has advantages of simple structure, ease of fabrication and large displacement by transverse vibration of a beam. It is easy to control the natural frequency, and also possible to increase the output power by changing the length, width, and thickness of the generator. In particular, the length increases, the natural frequency sharply decreases, and vice versa. Hence, the natural frequency can widely be controlled by using change in the length of elastic body. In this paper, the generator was designed and fabricated to change natural frequency using the slides of the case. In addition, the generating characteristics were confirmed through finite element analyses and vibration experiment. As a result, the maximum output characteristics could be generated due to resonance phenomenon although any frequency of external force was applied.

• 대한인간공학회지
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• 제32권6호
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• pp.489-494
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• 2013

Objective: This study compared the effects of streamlined shoes on dynamic gait and foot plantar pressure in healthy young adults. Background: With the importance of ankle and lower extremity mechanism, streamlined shoes are contributing to a static gait factors. However, the study of dynamic gait factor is still insufficient. Method: Sixty subjects were randomly allocated to two groups: experimental group(n=30) and control(n=30), respectively. The experimental group performed streamlined shoes, whereas the control group applied usual shoes. Main outcome measurements were assessed contact time, step length and foot plantar pressure using gait analysis with the treadmill. Independent t-test was used to compare the both groups. Results: Compared with control group, contact time of forefoot, midfoot and hindfoot decreased significantly in experimental group(p<.05), Step length increased significantly in experimental group(p<.05). Foot plantar pressure of midfoot and hindfoot increased significantly in experimental group(p<.05), whereas that of forefoot did not show significantly in experimental group(p>.05). Conclusion: Our findings suggest that streamlined shoes was more effective than usual shoes in dynamic gait change including contact time and step length and foot plantar pressure in healthy young adults. Application: The results of streamlined shoes might help to control for the gait of industrial workers.

• 로봇학회논문지
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• 제12권1호
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• pp.26-32
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• 2017

Previous shape sensors including bend sensors and optic fiber based sensors are widely used in various applications including goniometer and surgical robots. But theses sensors have large nonlinearity, limited in the range of sensing curvature, and sometimes are expensive. This study suggests a new concept of bend sensor using cable-conduit which consists of the outer sheath and the inner wire. The outer sheath is made of helical coil whose length of the central line changes as the sheath bends. This length change of the central line can be measured with the length change of the inner cable. The modeling and the experimental results show that the output signal of the proposed sensor is linearly related with the bend angle of the sheath with root mean square error of 5.3% of $450^{\circ}$ sensing range. Also the polynomial calibration of the sensor can decrease the root mean square error to 2.1% of the full sensing range.