• Journal of the Korean Society of Environmental Restoration Technology
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• v.8 no.1
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• pp.45-51
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• 2005

Total phosphorus(TP) removal was examined in a surface-flow wetland constructed in April 2003 during its initial operating stage from June to November 2003. Its dimensions were 87mL by 14mW. It was a part of a four-wetland-cell treatment system constructed near the Kohung Estuarine Lake located in the southern part of Korea. Effluent from a night soil treatment plant was discharged into the wetland and purified effluent from the wetland was discharged into Sinyang Stream flowing into the Lake. Cattails(Typha angustifolia ) from natural wetlands were cut at about 40 cm height and transplanted into the wetland. An average of 25.0$m^3$/day of effluent flowed from the plant into the wetland. Water depth was maintained about 0.2m and hydraulic detention time was about 5.2 days. Average heights of the cattail stems in June and October 2003 were 47.2 and 164.6cm, respectively. The average number of stems was 10.2 stems/$m^2$ in June 2003 and 18.8 stems/$m^2$ in October 2003. Average temperature of influent and effluent ranged 23.4 and $24.2^{\circ}C$, respectively. The average TP concentrations of influent and effluent were about 1.31, 0.50mg/L, respectively. TP loading rate of influent into the wetland averaged 26.81mg/$m^2$, day and average TP loading rate of effluent was 10.04mg/$m^2$, day. Monthly average TP removal by the wetland during the warm growing season of cattails(June to September) ranged 16.28~19.57mg/$m^2$, day and during the cold senescent period (October to November) ranged 12.62~13.90mg/$m^2$, day. TP removal in the wetland continued during the cold winter months and was primarily done by sedimentation and precipitation of phosphorus rather than phosphorus absorption by cattails and microorganisms.

• The Research Journal of the Costume Culture
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• v.16 no.4
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• pp.646-660
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• 2008

Korean export of fashion products to the U.S. has fallen off sharply after 2001. Now, Korean fashion companies have to develop higher value-added business. In the U.S., Korean-American fashion companies are taking a primary role in up-stream of the fashion industry. To cut the edge over the U.S. fashion companies, one of the solutions could be to build the business relationship with Korean fashion companies which reflect the recent trend rapidly and have high quality production. On this study, we investigated the marketing strategies of Korean-American fashion companies to seek to start business with Korean fashion companies and make suggestions for Korean fashion companies who want to enter into the U.S. market effectively. To analyze current situation of Korean export to the U.S. and the U.S. fashion industry, we considered various kinds of statistic data, publications and studies. And we performed in-depth interviews with 9 Korean-American fashion companies in LA from $9^{th}$ to $21^{st}$ of July. The results are as follows. first, Korean fashion companies should aim for high-end market with the products of high quality and design. Second, there should be professional agents who manage Korean small-medium fashion companies and connect them with Korean-American fashion companies. Third, Korean fashion companies who want to enter into the retail market of the U.S. have to decide the target market clearly and plan strategic and differentiated merchandising. Fourth, Korean fashion companies can specialize in product developing service like proposing a product or a merchandising line as a package including designs, fabric swatches, trims, production information, etc.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.7 no.3
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• pp.95-99
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• 2002

3.5KHz subbottom profiling systems are useful for delineating of shallow (up to 10~100m below the sea bottom) geological structure. These systems are generally used to image geological structures with less than 1m of vertical resolution. However swell in the sea is quite often higher than 1m, causing degradation in the quality of the 3.5KHz subbottom profiles. In this paper, we show the quality of digitally recorded data can be enhanced by the suppression of swell effect. Prior to suppression of swell effect, sea bottom detection procedure was applied using the characteristics that the amplitude of sea bottom reflection is high. To suppress the swell effect, we applied moving average method and high-cut filtering method using the extracted water depth of adjacent traces. Acceptable results were obtained from both methods. In the case of bad quality data or shallow data interfered with direct wave, the suppression of swell effect is difficult due to incorrect sea bottom detection.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.8
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• pp.62-69
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• 2010

Internal lathe machining with a boring bar is weak with respect to vibration because the bar is long and slender. Therefore, it is important to study the dynamic characteristics of a boring bar. The purpose of this study was to identify the effects of overhang and cutting conditions on the dynamic response characteristics of a boring bar. For an efficient experiment, an $L_g(3^3)$ orthogonal array was applied and the results were quantitatively analyzed by ANOVA. Overhang, feed per revolution, and depth of cut were selected as independent variables. Meanwhile, dynamic stiffness, damping ratio, damping coefficient, and acceleration were chosen as dependent variables. The vibration signal was obtained from an accelerometer attached to the boring bar, followed by visualization by a signal analyzer. The effect of overhang was found to have a significant effect on the dynamic stiffness, damping ratio, and damping coefficient, but the other variables did not. As the length of the overhang increased, the dynamic stiffness decreased and the damping ratio increased. In addition, the damping coefficient increased until the length of the overhang was 4D (where D is the shank diameter), after which it remained constant. The acceleration decreased until the overhang length was 4D, and then increased sharply when the overhang was increased further. From these results, the behavioral trend of the damping characteristics changed when its overhang length was 4D. Consequently, there is a critical point that the dynamic characteristics of boring bar change.

• Journal of the Earthquake Engineering Society of Korea
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• v.24 no.5
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• pp.219-232
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• 2020

The slip-weakening model developed by Ohnaka and Yamashita is extended over the breakdown zone by equating the scaling relationships for the breakdown zone and the whole rupture area. For the extension, the study uses the relationship between rupture velocity and radiation efficiency, which was derived in the theory of linear elastic fracture mechanics, and the definition of f_max given in the specific barrier model proposed by Papageorgiou and Aki. The results clearly show that the extended scaling relationship is governed by the ratio of rupture velocity to S wave velocity, and the velocity ratio can be determined by the ratio of characteristic frequencies of a Fourier amplitude spectrum, which are corner frequency, f_c, and source-controlled cut-off frequency, f_max, or vice versa. The derived relationship is tested by using the characteristic frequencies extracted from previous studies of more than 130 shallow crustal events (focal depth less than 25 km, M_W 3.0~7.5) that occurred in Japan. Under the assumption of a dynamic similarity, the rupture velocity estimated from f_max/f_c and the modified integral timescale give quite similar scale-dependence of the rupture area to that given by Kanamori and Anderson. Also, the results for large earthquakes show good agreement to the values from a kinematic inversion in previous studies. The test results also indicate the unavailability of the spectral self-similarity proposed by Aki because of the scale-dependent rupture velocity and the rupture velocity-dependent f_max/f_c; however, the results do support the local similarity asserted by Ohnaka. It is also remarkable that the relationship between the rupture velocity and f_max/f_c is quite similar to Kolmogorov's hypothesis on a similarity in the theory of isotropic turbulence.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.8
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• pp.93-98
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• 2021

The complex effects of the machining parameters make it is difficult to control and predict surface roughness. The theoretical surface roughness observed during mechanical machining with a round tool is determined by the tool radius and pitch. However, it was revealed that other parameters, such as the depth of cut and cutting speed, also affect surface roughness. This study adapted the Taguchi method, which can analyze the effects of cutting parameters quantitatively with an efficient number of experiments, to optimize the parameters for better surface roughness. Experiments were designed based on an orthogonal array, and the quantitative effects on the surface roughness were analyzed using the S/N ratio. The surface roughness was affected by all parameters, especially the tool radius. The optimum cutting parameter values obtained in this study showed better surface roughness than the other combinations of the parameters.

• Journal of the Korean Society of Costume
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• v.65 no.3
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• pp.131-150
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• 2015

This article studied the procedures and items used in royal princess weddings by examining "Garyedeungrok(嘉禮謄錄)" which describes Princess Hwasun(和順翁主, 1720-1758)'s wedding in 1732. This was the first wedding by a princess during King Yeongjo(英祖)'s reign. Preparation for the wedding was made based on the previous weddings of royal princesses, but it did not follow the old tradition. The wedding costs were cut down, and it was done in a simpler way than before. However, the simplification of elaborate wedding outfits were not part of this change as ceremonial robes such as No-ui(露衣), Jangsam(長衫) and Chopo(綃袍) were used without much alteration. The wedding ceremony of Princess Hwasun shows the transition process from the royal princess wedding ceremony traditions and rituals in the late 17th century to "Gukhonjeongrye", which emerged and became solidified as a new social norm in the 18th century. A legitimate royal princess and a de facto princess from King's concubine were hardly different when it came to their royal outfitting but the disparity in social status between the two was found in the materials used to make clothes for their respective husbands. Princess Hwasun's wedding procedure shown in "Garyedeungrok" is similar to that of "Gukjo-orye-ui(國朝五禮儀)": Napchae(納采), Nappye(納幣), Chinyeong(親迎), Dongroe(同牢), Hyeongugo(見舅姑), Hyeonsadang(見祠堂), and Seojohyeon(壻朝見). But "Garyedeungrok" deals with the procedures of Gantaek(揀擇), Buma-guanrye(駙馬冠禮), and Seonon(宣醞), which are not included in "Gukjo-orye-ui", and also with the process of preparation for wedding items and the information of related people. However, it is hard to learn about its specific shapes and features because it is often restricted to lists such as a list of clothing. Collecting new materials and an in-depth and succeeding study are required in the future.

• Journal of Korea Game Society
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• v.8 no.4
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• pp.17-27
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• 2008

This study has made an in-depth analysis of the 'Puzzle System' which is a characteristic structural unit of the Adventure Game, and concentrates on the mechanism where the experience arouses in the player a 'desire (quasi-need) to finish' that leads to one's immersion and engagement in the game. In the course of conducting this study, documentary records were consulted and also this writer personally played video games to learn the component elements and fundamental characteristics of the Adventure Games and to experience how the player was immersed in the game. Thus, the Puzzle System in the Adventure Game was defined and an analysis was made of the structure and course of play where the puzzle part and the narrative part within the system organically interacted between them in the system. In order to confirm the formation and effects of 'desire to finish' shown in the hypothetic assumptions, two experiment-purpose game units were produced, one with dramatic cut scenes and the other without them, so that differences between them could be found. I also conducted an experiment to learn the generation and effect of the 'desire to finish' of the Puzzle elements by using different games with a varying degree of difficulty.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2006.11a
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• pp.127-132
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• 2006

Quantization in video coding plays an important role in controlling the bit-rate of compressed video bit-streams. It has been used as an important control means to adjust the amount of bit-streams to at]owed bandwidth of delivery networks and storage. Due to the dependent nature of video coding, dependent quantization has been proposed and applied for MPEG-2 video coding to better maintain the quality of reconstructed frame for given constraints of target bit-rate. Since Scalable Video Coding (SVC) being currently standardized exhibits highly dependent coding nature not only between frames but also lower and higher scalability layers where the dependent quantization can be effectively applied, in this paper, we propose a dependent quantization scheme for SVC and compare its performance in visual qualities and bit-rates with the current JSVM reference software for SVC. The proposed technique exploits the frame dependences within each GOP of SVC scalability layers to formulate dependent quantization. We utilize Lagrange optimization, which is widely accepted in R-D (rate-distortion) based optimization, and construct trellis graph to find the optimal cost path in the trellis by minimizing the R-D cost. The optimal cost path in the trellis graph is the optimal set of quantization parameters (QP) for frames within a GOP. In order to reduce the complexity, we employ pruning procedure using monotonicity property in the trellis optimization and cut the frame dependency into one GOP to decrease dependency depth. The optimal Lagrange multiplier that is used for SVC is equal to H.264/AVC which is also used in the mode prediction of the JSVM reference software. The experimental result shows that the dependent quantization outperforms the current JSVM reference software encoder which actually takes a linear increasing QP in temporal scalability layers. The superiority of the dependent quantization is achieved up to 1.25 dB increment in PSNR values and 20% bits saving for the enhancement layer of SVC.

• Journal of Korean Library and Information Science Society
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• v.49 no.4
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• pp.405-427
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• 2018

This study examined system, form and contents of including its publication in depth through the analysis on the publication of those days, present condition of extant edition, system and publication, illustrator etc., targeting series which was published in the liberation period. As for series which was published by Eulyoo Publishing and Joseon Children Culture Association(Ahyeop) for building children's life liberation and children culture, 5 books still remain now. For the extinct edition, this study confirmed publication history of books based on the advertisement carried on the newspaper which was published of the time. As a result of analyzing extant edition, this study found that the book was composed equally as a system of cover, beginning, body and the end, and the body was characterized by the composition of 3-cut comic and story as a form of storybook. The size of the book is A5 book size with 32 pages of quantity and was published as a semi-hardcover bound book. As for illustrators, Kim brothers (Yong-hwan, Eui-hwan) who played an active part in the field of art of the time participated.