• Journal of Korean Society on Water Environment
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• v.22 no.2
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• pp.238-243
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• 2006

In order to improve the water quality of stream water, the facilities equipped with rope media filter have been examined as a part of national projects. This work may provide design and operating parameters from 2 years monitoring for 2 streams. Depending on the characteristics of streams, the flow rate into the facilities were shown different, where K stream was almost the same and D stream was less than 25% of design flow rate. Although the clogging of filter media was not observed during the operation, the removal of accumulated sludges was required for the stable operation. The removal efficiencies of BOD, SS, T-N and T-P for D stream were 60.5%, 80.1%, 25.2% and 36.2%, respectively. The most important factor for the construction of stream water purification facilities was recommended for the selection of proper sites.

• KSBB Journal
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• v.16 no.4
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• pp.332-336
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• 2001

This paper is intended as an application of the biological rope media sedimentation tank using biodegradability of BAC(Biological activated carbon) to the drinking water treatment system for the removal of NOM. The removal of DOC(Dissolved organic carbon), UV absorbance(UV$\_$254/), and turbidity were evaluated under various operation condition of a biological rope media sedimentation tank such as raw water-media process (Media 1), ozonation-media process (Media 2), and ozonation-coagulation/sedimentation-media process (Media 3). The raw water had DOC concentration of 1.3∼3.4 mg/L, UV$\_$254/ of 0.027∼0.039 cm$\^$-1/, and turbidity of 0.3∼4.5 NTU, respectively. The average DOC concentration were 2.2 mg/L in media 1, 1.8 mg/L in media 2, and 1.3 mg/l in media 3 from raw water, respectively. On the other hand, the DOC concentration in conventional sedimentation tank was 1.5 mg/l. Higher removal of the DOC was noted in media 3 than media 1 and media 2. The UV$\_$254/ of the treated water were 0.037 cm$\^$-1/ in media 1, 0.027 cm$\^$-1/ in media 2, and 0.014 cm$\^$-1/ in media 3 from raw water, respectively The UV$\_$254/ in conventional sedimentation tank was 0.014 cm$\^$-1/ which is similar to that of media 3. Average turbidity of the treated water was 1.1 NTU in media 1, 0.9 NTU in media 2, and 0.5 NTU in media 3, respectively. It is expected that the biological rope media sedimentation tank is a good alternative over the conventional sedimentation process from these results.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2003.11a
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• pp.27-30
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• 2003

본 논문에서는 하이브리드 다중 표현(hybrid multiple description) 개념을 이용하여 에러가 발생하기 쉬운 환경에서 사용될 수 있는 강인한 동영상 압축 알고리듬을 제안한다. 다중 표현 압축은 단일 표현 압축(single description coding. SDC) 보다 패킷 손실 율(packet loss rate, PLR)이 높은 환경에서 에러에 더 강인성을 갖는다. 그러나 PLR 이 낮은 환경에서는 과도한 중복량(redundancy) 때문에 성능이 저하되는 문제가 발생한다 이러한 MDC 의 문제를 해결하기 위해서 채널 환경에 따라 SD/MID 를 전환할 수 있는 방법을 제안한다. 좀더 자세히 설명하면, 낮은 PLR 에서는 압축 효율을 위하여 SDC 를 사용하고 높은 PLR 환경에서는 에러에 대한 강인성을 위해 MDC 를 사용한다. SD/MD 전환을 최적화시키기 위해 비트율-왜곡 최적화 프레임웍(rate-distortion optimization framework)을 사용한다. 부호화시에 복호기에서의 왜곡(distortion)을 정확히 예측하기 위해서 ROPE(recursive optimal per-pixel estimate) 방법을 사용한다. 모의 실험 견과 제안된 SD/MD 전환 방법이 기존의 SDC-ROPE 와 MDC-ROPE 보다 모든 에러 환경에서 더 효과적임을 알 수 있다.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.3
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• pp.367-372
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• 2008

This study configured the conventional $A^2O$ (Anaerobic-Anoxic-Aerobic bioreactor) system which the fixed media immersed into the anoxic reactor(Named PFR system : Plug Flow Reactor) for evaluating the removal efficiency of nitrogen in the wastewater. The experimental equipment was a cylinder which was consist of 4 pleated PE Pipes(Length 330M, Diameter 100mm) including 2 rope shape media. As a result, the average effluent T-N removal efficiency of the conventional $A^2O$ system was 17.9, 40.3, 50.6, 44.6% in each mode, but the average effluent T-N removal efficiency of the PFR system could achieve 38.8, 57.1, 71.8, 65.4% in each mode. It indicated that the PFR system caused to the increasing of C/N ratio that effected to the increasing of the denitrification efficiency. Not only the effective T-N removal efficiency but also the controllable install space will give advantages for retrofitting of the wastewater treatment plant with the conventional treatment system to the PFR system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.897-898
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• 2014

줄넘기는 오래전부터 건강운동과 미용체조의 일환으로 일반에게 널리 사용되고 있다. 최근에는 줄넘기의 손잡이와 줄에 다양한 기능을 부가하여 손잡이에 줄을 넘은 횟수를 카운트하여 표시해 주거나, 스피커를 구비하여 음성출력을 부가하거나, 줄의 재질 및 형태도 다양화하여 줄의 무게를 조절할 수 있는 기능을 부가하고 있다. 본 논문에서는 운동하는 사람의 정보를 기반으로 적절한 운동량을 조절하도록 사용자의 줄넘기 횟수 및 운동 시간 등을 스마트폰으로 전송할 수 있는 스마트 줄넘기 모듈을 블루투스(bluetooth) 기반으로 개발하고자 한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.56-63
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• 2018

The management of Combined Sewer Overflows(CSOs) and Separated Sewer Overflows(SSOs) discharge directly to the effluent system in an untreated state, which occurs when the facility capacity is exceeded due to heavy rain, has become an important issue in recent years as the heavy rain becomes a regular phenomenon. Despite the continuous development of filtration technology, targeting densely populated urban areas, CSOs are rarely applied. Therefore, this study was carried out to optimize the process to apply CSOs in a pilot-scale horizontal flow filtration system with a rope-type synthetic fiber. The research was carried out in two steps: a preliminary study using artificial samples and a field study using sewage. In the preliminary study using an artificial sample, head loss of the filter media itself was analyzed to be approximately 1.1cm, and the head loss was increased by approximately 0.1cm as the linear velocity was increased by 10m/hr. In addition, the SS removal efficiency was stable at 81.4%, the filtration duration was maintained for more than 6 hours, and the average recovery rate of 98% was obtained by air backwashing only. In the on-site evaluation using sewage, the filtration duration was approximately 2 hours and the average removal efficiency of 83.9% was obtained when belt screen (over 450 mesh) was applied as a pre-treatment process to prevent the premature clogging of filter media. To apply the filtration process to CSOs and SSOs, it was concluded that the combination with the pre-treatment process was important to reinforce the hydraulic dimension for the stable maintain of operation period, rather than efficiency. Compared to the dry season, the quality of incoming sewage was lower in the rainy season, which was attributed to the characteristics of the drainage area with higher sanitary sewerage. In addition, the difference in removal efficiency according to the influent quality of the wet season and dry season was small.

• Korean Journal of Legislative Studies
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• v.22 no.2
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• pp.113-156
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• 2016

Media scholars take a lion stake in power circle. Not only do they take a part in media policies but seize prestigious positions like board members in Korea Communication Commission(KCC). Unfortunately, though, little has been known about who they are, what qualifications they have, and whether they meet public interests. This paper attempts to unveil the mechanism of those politicized intellectuals who are specialized on the media. Two categories divided into 'representative' and 'expertise' are employed for this purpose. On the one hand, the representative means the degree of committment into such public services as participation in conferences or non-profit organizations. On the other hand, the number of research articles, books and projects belong to the expertise. Evaluation levels consist of 'excellence, good and average' were allocated to those scholars who are(were) in 'Power Hole,' where decision makings come into being. Some interesting observations were made though this study. First of all, such criteria as representative and expertise vaguely suggested by the laws were hardly fit into those intellectuals, Rarely did they commit into public service let alone showing vigilance in academic activities. Secondly, both ideological loyalty and political activities in line with the government had much to do with taking such positions. Thirdly, not surprisingly, it showed that to graduate from Seoul National University and have Ph.D. degree from U.S.A. was one of the most essential factors. In final, most of them were very good at taking advantage of the press in way of boosting their publicity. To attend at policy making processes either in form of board members or advisers is inevitable for media experts. However, as shown in this study, such qualification of public service and academic eagerness shouldn't be underestimated. Academic integrity not selling intelligence solely for private interests needs to be protected as well. The authors hope this study to provide a valuable opportunity to establish a kind of ethical standards in participating into politics.

• Journal of Broadcast Engineering
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• v.9 no.1
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• pp.17-31
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• 2004

This paper proposes an algorithm for the robust transmission of video in error Prone environment using multiple description codingby optimal split of DCT coefficients and rate-distortionoptimization framework. In MDC, a source signal is split Into several coded streams, which is called descriptions, and each description is transmitted to the decoder through different channel. Between descriptions, structured correlations are introduced at the encoder, and the decoder exploits this correlation to reconstruct the original signal even if some descriptions are missing. It has been shown that the MDC is more resilient than the singe description coding(SDC) against severe packet loss ratecondition. But the excessive redundancy in MDC, i.e., the correlation between the descriptions, degrades the RD performance under low PLR condition. To overcome this Problem of MDC, we propose a hybrid MDC method that controls the SDC/MDC switching according to channel condition. For example, the SDC is used for coding efficiency at low PLR condition and the MDC is used for the error resilience at high PLR condition. To control the SDC/MDC switching in the optimal way, RD optimization framework are used. Lagrange optimization technique minimizes the RD-based cost function, D+M, where R is the actually coded bit rate and D is the estimated distortion. The recursive optimal pet-pixel estimatetechnique is adopted to estimate accurate the decoder distortion. Experimental results show that the proposed optimal split of DCT coefficients and SD/MD switching algorithm is more effective than the conventional MU algorithms in low PLR conditions as well as In high PLR condition.

• Journal of Korean Academy of Nursing
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• v.3 no.3
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• pp.36-49
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• 1973

This study was carried out for the objectives to collect the basic informations on the health behaviors of the elementary school children in an urban area in Korea. Seven hundred students were drawn to fill in the designed questionnaire which carries variety of Questions on health re-lated behaviors in general, eating habits, disease history, mental health, and sex education. Questionnaire were filled in by their parents. Major findings are as follows: ① 55.7% had habits of washing the hands before eating whereas 59.8% trashing their hands after toilet. The others had no idea of washing hands before eating and after toilet. ② 26,5% had habits of brushing the teeth twice a day 54.7% only once in the morning, and 2.6% once only in the evening. Thus, the idea of prevention from decayed teeth seems to be lacking among the school children. ③ Bathing habits were also inquired to get 40.3% of bathing more than once a week, 43.1% once every two weeks, and the rest of 16.6% once every one to three months. ④ 41.7% keep the regular bedding time whereas 58.3% irregular. Physical exercises were con-ducted by 76.6% on the ground while 23.5% did not practice any physical exercises at all. Of those physical exercises, rope skipping occupied 37.5%, and the other 66.9% consisted of 14 different kinds of individual type physical exercises such as gymnastic exercise. The main reasons for not enjoying exercises were different by sex; boys largely complained the inadequacy and lack of gymnastic facilities and girls felt in short of friends who could join the exercises. ⑤ 31.9% of the school children had been taking not much of food while 28.3% had unbalanced diets. Of these unbalanced diets, meat occupied 33.2% to be the priority to have an order of the following items such as vegetables, bread or noodle, and fishes as next to each. For eating habits, 88.5% take simple snack such as bread (38.4%, cookies, fruits, and candies in order. 25.8% of the children were provided such snacks or their parents regularly. Breakfast was sufficiently taken by 45.0% whereas 8.4% had never sufficiently. As to the lunch, 63.6% had sufficiently while 16.8% insufficiently. 70.6% take breakfast with all family members together and 30.4% separately. Correlation of sufficient taking of breakfast and eating together of tile family member's seems to be significant when we compare 72.5% of sufficient takers who enjoy breakfast together with the family members with 55.6% of insufficient takers who enjoy it with the family. This finding allows the investigator to point out the importance of table circumstances for children's eating. ⑥ The most common disease was catching a cold (38.8%), and the second was stomach trouble to be followed by the frequency of car sickness, headache, and skin infection. Doctors are consulted only by 23.9% when they are sick whereas 59.7% resorted to the drug stores. The lower the educational attainment of the parents, the lower the rate of visiting clinics. ⑦ 36.7% of their parents pointed out the problems of personality guidance as the most difficult thing at home 71.3% of their parents worried about and unsatisfied with their children's personality traits. Of these complains of the parents, impatience stood at the top to be tabulated at 24.1%, and 21.1% indicated narrow-mindedness. In line with this primary socialization at home, the most crucial problem seems to be related with the lack or recognition of the parents'own role when we find only 43.1% of the parents understood the importance of their own role for the home education of children; the latter group attributed tile responsibility of personality formation to the children themselves. ⑧ As to the sex educational aspects, 30.9% of children have ever asked about the physiology of reproduction or sexual matters to their parents, of those parents only 17.0% could give the constructive responses to the inquiries of the children. In companies on with these data, 25.6% recognized their own role in sex education for their own children while the large segments of the parents (51.1%) attributed the responsibility of sex education to tile low level of 38.3% who recognized the importance of sex education in the school curriculum and 25.1% of the parents insisted to wait until they get to know naturally about sex. 38.1% of the parents said they had some knowledge on sex from books while 16.9% through mass media. The next groups had common senses of sex from their own parents, school friends and other sources.