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        검색결과 346

        81.
        2016.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Phosphorus is an essential and irreplaceable element for all living organisms and its resource is limited. Significant amount of used phosphorus is collected in sewage treatment plant as sludge. Sludge ash after incineration contains about 10% of phosphorus in dry mass basis, which is comparable to phosphate rocks, and it is an important source of phosphorus recovery. Acid and alkali were used to leach phosphorus from sludge ash and compared for their leaching kinetics and performance. Phosphorus leaching by NaOH was fast and 0.2 N and 2 N NaOH leached 49% and 56% of the total phosphorus in the sludge ash at the L/S ratio of 100. Phosphorus leaching by sulphuric acid and hydrochloric were very fast and most of the phosphorus was leached in 5 minutes. In case of sulphuric acid 95% of the total phosphorus in the sludge ash was leached by 0.2 N at the L/S ratio of 100 and 93% was leached by 1 N at the L/S ratio of 10. 1 N hydrochloric acid leached 99% of the total phosphorus at the L/S ratio of 10. The results showed acids were more effective than alkali for phosphorus leaching from sludge ash and hydrochloric acid leached more phosphorus than sulphuric acid.
        4,000원
        82.
        2016.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study conducted a survey with 203 single households among men and women in their 20s to 40s who were living in metropolitan areas from October 6 to November 4, 2012 in order to investigate the dietary attitude of the single households. The ratio of single households who had three meals a day regularly was 2.85 points, which was lower than the normal level, and it turned out that those in their 20s and 30s had meals more regularly than those in their 40s did (p<0.001). As for the irregular meal time, most were breakfast (85.9%), and it turned out that they often skipped meals mostly because they did not have time to eat and (41.7%) or because that bothered them (26.0%). 62.6% of the single households did overeating and most of them (39.4%) did overeating because of their irregular meals. Of the single households, women or persons who had lived alone for less than 3 years or more than 7 years cooked at home, more often (p<0.05), and most of them (42%) cooked noodles, easy to cook, but women cooked Korean food-based homemade food such as rice (31.7%) or soup and stew (21.2%), often (p<0.05). It turned out that 36.9% of the single households often ate out about two to three times a day, and as for their favorite eating-out menus, 39.4% were Korean food, followed by Western food (23.8%), flour-based food (13.5%), fast food (9.8%), Chinese food (7.3%) and Japanese food (6.2%). Lastly, as for inconveniences when they ate out, most were the ‘price’ (22.8%), followed by ‘too much amount of food for one person’ (20.2%) and ‘limitations in menu selection’ (19.2%). As a result of this study, it appeared that the single households had an irregular dietary life, often did overeating and often ate out, so it is judged that it would be necessary to develop a variety of nutritionally-balanced HMR food and eating-out menus in a reasonable price range for their healthy dietary life.
        4,200원
        83.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        All games support the meaningful play, and each mechanism producing meaning is various. In mobile role-playing game, automation of in-game action standardizes movements of avatars and diversify combat challenges. Thereby players reinforce their avatars and make various repertoires so as to cope with different contents. Players predict the result of their own actions based on short-term, juicy feedbacks. In conclusion, mobile role-playing game has 'strategy' as its action mode while the unit time required for meaningful play is highly reduced. This analysis is significant in the sense that it was the first step toward integrated change of game play experiences.
        4,000원
        84.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The variants of references in dictionary reflect many characteristics of particular regions and era. These variants are also the key points to the research of characters’ dissemination and application. This paper based on the Access of xinzidian, reorganized all the references to Liji, and then made a comparison between the references and Liji. As a result, we found 100 variants, and summarized them as five types. Then on this basis, we attempt to discuss the features and laws of Korea’s characters.
        4,300원
        85.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The Assisted evidence of Shuo Wen Jie Zi(《說文解字翼徵》)was written by Piao Xuan Shou who is a famous scholar in Joseon Dynasty. This is South Korea's only remaining book that The author was first use of Chinese bronze inscriptions, Seal characters and drum-stone inscriptions to research Shuo Wen(《說文》). By this way, The author want to correct the mistake of Shuo Wen. So it is stand for that the philology researching reached new heights. However, there are still quite a few defects and shortcomings in the book, like follow blindly view of Xu Shen and wrong to knew Chinese bronze inscriptions. For the Chinese scholars, this book have some effects like “Stones from other hills may serve to polish the jade of this one”. As an example with 12 characters from Bronze inscriptions of Yu Tripod (《大盂鼎銘文》) that it had quoted in this book, and the current Academic research Can be checked with the view of correction Shuo Wen. So that this book can be evaluated and inherited.
        4,600원
        86.
        2016.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Magnetite particles were synthesized by co-precipitation of water-soluble 밀 스케일-derived precursor by various concentrations of (0.5, 0.67, 1, 2 N) NaOH and (0.6, 0.8, 1.2, 2.4 N) NH4OH. It is theoretically known that as the concentration of the alkaline additive used in iron oxide synthesis increases, the particle size distribution of that iron oxide decreases. This trend was observed in both kind of alkaline additive used, NaOH and NH4OH. In addition, the magnetite synthesized in NaOH showed a relatively smaller particle size distribution than magnetite synthesized in NH4OH. Crystalline phase of the synthesized magnetite were determined by X-ray diffraction spectroscopy(XRD). The particles were then used as an adsorbent for phosphate(P) removal. Phosphorus adsorption was found to be more efficient in NaOH-based synthesized magnetite than the NH4OH-based magnetite.
        4,000원
        87.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Measurement of soil phosphorus(P) that affects crop growth is important in regard to determining the amount of P to be top-dressed. Although numerous methods to measure soil P are available, they mostly implemented in a lab and require considerable time for analyzing. The objective of this study was to find a rapid way for Lancaster colorimetry to analyze soil P effectively and rapidly in a field. 20 soil samples each in Jinju and Geochang, Geongnam were collected and the experiment was conducted based on Lancaster. The colorimetric process can be divided into three stages: extraction, filtration and color development. To find reduced optimum extraction time, the soils were blended with a mixer at intervals of 30sec for 30sec to 2min. Syringe filters with the sizes of 0.45, 1 and 2㎛ and a syringe compressor were used for speed up of filtration. The extracted solutions with reagents were soaked in the bath with 30, 40 or 50°C at intervals of 30sec for 30sec to 2min for optimum rapid color development. Combined Rapid Lancaster(CRL) method was performed for the soil samples using the best results from each process, which was 30sec blending using a mixer, 0.45㎛ syringe filter and absorbance measurement after 2min immersion at 50°C. As a result of the CRL method, R2 for Jinju soil and Geochang soil showed 0.791 and 0.936 respectively when compared to the standard Lancaster method. Since there was no statistically significant difference between Lancaster and the CRL, it was considered that the CRL method could be used to analyze soil P as a substitute for Lancaster. Future study will be conducted with wet field soils in various regions.
        4,200원
        88.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In mobile communication systems, location management deals with the location determination of users in a network. One of the strategies used in location management is to partition the network into location areas. Each location area consists of a group of cells. The goal of location management is to partition the network into a number of location areas such that the total paging cost and handoff (or update) cost is a minimum. Finding the optimal number of location areas and the corresponding configuration of the partitioned network is a difficult combinatorial optimization problem. This cell grouping problem is to find a compromise between the location update and paging operations such that the cost of mobile terminal location tracking is a minimum in location area wireless network. In fact, this is shown to be an NP-complete problem in an earlier study. In this paper, artificial bee colony (ABC) is developed and proposed to obtain the best/optimal group of cells for location area planning for location management system. The performance of the artificial bee colony (ABC) is better than or similar to those of other population-based algorithms with the advantage of employing fewer control parameters. The important control parameter of ABC is only ‘Limit’ which is the number of trials after which a food source is assumed to be abandoned. Simulation results for 16, 36, and 64 cell grouping problems in wireless network show that the performance of our ABC is better than those alternatives such as ant colony optimization (ACO) and particle swarm optimization (PSO).
        4,000원
        89.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문은 이자이의 《무반주 바이올린 소나타》 제2번 1악장에 대한 분석이다. 바흐의 《파르티타》 제3번 ‘프렐류드’와 그레고리성가 ‘진노의 날’에서 인용한 선율을 특징으로 하는 이 곡은 과감한 화성과 혁신적인 연주 기법으로 인해 독창적이며 동시에 실험성 짙은 작품으로 평가된다. 그러나 이 악곡이 취하는 소나타 형식의 구조와 디자인은 전통적인 틀 안에서 실험적 요소를 성공적으로 녹여낸 이자이를 절충주의 작곡가로 평가하게 한다. 바흐의 E장조 프렐류드는 이자이에 의해 a단조의 딸림화음으로 재맥락화되어 제1주제로 기능하고 있으며, 선법성 짙은 그레고리성가 역시 그 명맥을 유지한 채 딸림조성인 e단조에서 제2주제로 기능한다. 바흐와 이자이 사이 나타나는 다층적 대조는 유려한 성부진행을 만들며 쉔커가 말하는 소나타 형식의 제시부 조건을 충족시킨다. 거시적 버금딸림화음을 연장하는 발전부는 쉔커가 말한대로, 딸림화음을 향해 진행하지만 46화음을 통한 이례적 접근은 작품이 갖는 독창성을 확보해준다. 으뜸화음의 복귀와 함께 이루어지는 ‘진노의 날’은 재현부의 시작을 알리며, ‘뒤바뀐 소나타 형식’의 디자인을 제안한다. 원조성인 a단조 위에서 펼쳐지는 주제 요소들의 재배열은 바흐와 이자이 사이의 첨예한 대조를 죽음을 향한 비극으로 승화시킨다.
        7,000원
        90.
        2016.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Phosphorus (P) removal by aluminum sulfate solution was investigated with varying pH and initial P concentrations. P removal was the highest at around pH 6. The pH range where P removal occurred was slightly wider at higher initial P concentrations. Compared to theoretical calculations, it was confirmed that AlPO4 precipitation was the main reason for P removal at low pH. At high pH, where there should be no AlPO4 precipitates, the P removal by adsorption of amorphous Al(OH)3 precipitates was experimentally observed. The P removal by adding amorphous Al(OH)3 precipitates prepared before the adsorption experiments, however, was lower than that by injecting aluminum sulfate solution because the prepared precipitates became larger, leading to less specific surface area available for adsorption. Ions other than sulfate had little influence on P removal.
        4,000원
        91.
        2016.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The increases of industrial and technological development and human activities have disturbed the balance of natural nitrogen (N) circulation. These phenomena have induced that large amounts of N are to be present in excess in air, soil and water environment. We investigated the effects of excess of reactive nitrogen (Nr) compounds on soil and water environment ecosystems through literature and case studies, and suggested the strategy of mitigating the acidification in soil and water ecosystems. Nr moves to air, soil and water media, can be converted to different types, and interacts with other chemical compounds. As an efficient N management plan, the evaluation (application of monitoring and safety index) and the chemical restoration (research and development) of the acidification in soil and water environment ecosystems are required to minimize the effects of Nr as well as policies to regulate the various emission sources and amounts of Nr.
        4,000원
        92.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was carried out for characterization of MIO synthesized in our laboratory by co-precipitation method and applied isotherm and kinetic models for adsorption properties. XRD analysis were conducted to find crystal structure of synthesized MIO. Further SEM and XPS analysis was performed before and after phosphate adsorption, and BET analysis for surface characterization. Phosphate stock solution was prepared by KH2PO4 for characterization of phosphate adsorption, and batch experiment was conducted using 50 ml conical tube. Langmuir and Freundlich models were applied based on adsorption equilibrium test of MIO by initial phosphate solution. Pseudo first order and pseudo second order models were applied for interpretation of kinetic model by temperature. Surface area and pore size of MIO were found 89.6 m2/g and 16 nm respectively. And, the determination coefficient (R2) value of Langmuir model was 0.9779, which was comparatively higher than that of Freundlich isotherm model 0.9340.
        4,000원
        93.
        2015.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The influencing factors to remove phosphate were evaluated by converter slag (CS). Experiments were performed by batch tests using different CS sizes and column test. Solutions were prepared at the different pH and concentrations. The maximum removal efficiency was obtained over 98% with the finest particle size, CSa within 2 hours in batch tests. The removal efficiency was increased in the order of decreasing size with same amount of CS for any pH of solutions. The adsorption data were well fitted to Freundlich isotherm. From the column experiment, the specific factors were revealed that the breakthrough removal capacity (BRC) xb/mcs, was decreased by increasing the influent concentration. The breakthrough time, tb was lasted shorter as increasing the influent concentration. The pH drop simultaneously led to lower BRC drop during the experimental hours. The relation between the breakthrough time and the BRC to influent concentration was shown in the logarithmic decrease. Results suggested that the large surface area of CS possessed a great potential for adsorptive phosphate removal. Consequently particle size and initial concentration played the major influencing factors in phosphate removal by converter slag.
        4,000원
        94.
        2015.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        24-hour recall is the dietary assessment method most frequently used to evaluate dietary intake; however, accuracy is an issue when using this method, especially in large-scale studies. The purpose of this study was to assess the validity of dietary intake estimation using one serving size. Estimates of energy and nutrients taken in over a 24-hr period based on actual intake amount (24HRAI) and based on estimates of one serving size (24HRSS) were compared. Data were analyzed using a paired t-test, Pearson’s correlation coefficients, and a cross-classification method. In male subjects, intake levels of energy, fat, vitamin C, vitamin B1, Zn, and total food measured using 24HRAI were significantly higher than those measured using 24HRSS. In female subjects, intake of carbohydrates, fiber, fat, vitamin A, vitamin C, vitamin B complexes, various minerals, and total food measured using 24HRAI were significantly lower than those measured using 24HRSS. Energy-adjusted Pearson’s correlation coefficients revealed that intake of all nutrients showed a significant positive relationship between the two measurement methods in both males and females. Cross-classification analysis revealed that 50.5~67.6% of women and 40.3~71% of men were classified in the same quartile of intake of each nutrient when comparing data from 24HRAI and 24HRSS. We conclude that using one serving size in 24-hr recall analysis was valid and therefore may be used in studies to assess food consumption in the general adult population. Also, this method can be used to classify energy and nutrient intake into quartile, which is useful in examining the association between diet and chronic diseases.
        4,000원
        95.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the pharmacodynamics of betaine on the blood profile and short chain fatty acid levels in meat ducks exposed to heat wave. 400 heads of Cherry valley (Anasplatyrhynchos) meat ducks were completely randomized to 5 treatments (4 repetitions each), and were raised for 42 days. They were grouped into T1 (heat wave control group without betaine), T2 (betaine 400 ppm), T3 (betaine 800 ppm), T4 (betaine 1200 ppm), and T5 (normal control group without betaine). Compared to T1, the betaine addition groups showed higher body weight gain at shipment, with T3 showing the highest significant difference. For hematological indictors measured (red blood cells and platelets), the betaine addition groups showed significantly higher values than the heat wave control group. The pH of the former was lower but their electrolytes (K+, P+, and Cl-) were significantly higher compared to the latter. For blood gas concentration, the former showed a significantly higher value than the latter. For the total short chain fatty acids, acetic acid, and propionic acid, the betaine addition groups and group fed broiler-high temperature diet showed higher values than the heat wave control group. On the other hand, the former showed significantly lower values in butyric acid, isobutyric acid, valeric acid, and isovaleric acid than the latter group. These results suggest that betaine has the pharmacodynamics that mediate heat stress, via the maintenance and control of the blood profile, osmotic pressure, gas concentration, and short chain fatty acid, of meat ducks under heat wave.
        4,200원
        96.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this thesis is to contribute in establishing the objectives of government policies through an empirical analysis on the relational characteristics surrounding the self-employed creative enterprises under the current circumstances where the specific empirical studies on the self-employed creative enterprises haven't been performed. According to the result of verification, the social capitals such as reliability, reciprocity and network are necessary due to the characteristics possessed by the self-employed creative enterprises while the reliability between cooperative enterprises is created and the cooperative relationship continues when the enterprises are faithful to their intrinsic activities such as the improvement of productivity rather than the entrepreneur spirit. Such win-win cooperation was eventually shown as having a positive effect on the performance of enterprises.
        4,000원
        97.
        2015.05 구독 인증기관·개인회원 무료
        Excess phosphorus in water has become a crucial aspect concerning the eutrophication. Experiments were carried out to fabricate particles of iron oxide to polymer and the beads were then calcinated. It was found that adsorption process most satisfactory fitted to Langmuir equation (R2>0.92) with maximum adsorption capacity 2.663 mg P/g adsorbent. Equilibrium of adsorption was reached after 3 h, while the initial adsorption rate increased from 0.46 mg/g-h to 3.83 mg/g-h when the bead iron content increased from 40.4 mg Fe/g to 160 mg Fe/g. This research was supported by a project (No. 2013001390002) from the Korea Environmental Industry & Technology Institute funded by the Ministry of Environment and the Brain Korea 21 Plus program of the Korean government.
        98.
        2015.05 구독 인증기관·개인회원 무료
        분리막 생물반응기(MBR)는 전통적인 수처리 방법과 비교하여 안정적인 수질확보, 처리부지 감소, 높은 유기물 제거 등의 장점으로 인하여 매우 널리 사용되고 있다. 그러나 긴 고형물 체류시간과 높은 미생물 농도로 인하여 종종 인제거에 제한이 있다. 전통적으로 인을 제거하기 위해 화학적 침전 방법이 가장 널리 사용되고 있으나 이는 과량의 응집제 주입으로 인한 비용 문제 및 대량의 슬러지 발생의 한계점을 가지고 있다. 반면 흡착공정은 상대적으로 운전이 쉽고 간단하며 슬러지 발생량을 현저히 줄일 수 있는 방법이다. 따라서 본 연구에서는 입상 금속산화물 흡착제를 개발하고 이를 이용하여 MBR처리수 내의 인을 제거하는데 적용하고 성능을 평가하였다. 본 연구는 환경부의 연구비(과제번호 2013001390002)를 지원받아 진행되었습니다.
        99.
        2015.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        전세계적으로 2000년대 이후로 남조류에 의한 녹조의 발생이 증가하고 있으며, 이와 관련된 환경 문제가 공중건강을 위협하고 인간 활동을 제한하고 있다. 1970년대 캐나다의 호수를 중심으로 수행된 다년간의 현장 연구를 통하여, 녹조발생의 핵심적인 영양 제한인자로 인이 제시되었고, 인 저감에 대한 수계 관리가 진행되었다. 그러나 2000년대 이후, 대형 담수수계에서 특히 Microcystis에 의한 녹조 현상에서는 인뿐만 아니라 질소가 남조류 녹조 발생에 미치는 영향이 부각되고 있다. 한국의 담수 수계에서도 이와 비슷한 남조류에 의한 위해성 녹조 번성 특징을 갖고 있으므로, 이러한 패러다임의 변화는 국내 담수수계의 영양염류 관리에서 중요한 의미를 갖는다. 최근 국제적인 관련 연구를 통하여, 위해성 남조류 번성을 막기 위해 제안된 방법은 다음과 같다. 1) 질소와 인을 함께 관리하는 전략, 2) 폐수의 수집 및 처리, 3) 호소 유입수의 사전처리, 4) 저니의 준설, 5) 체류시간의 단축, 6) 조류의 효율적 회수법, 7) 조류의 침강 및 응집 등이 제시되고 있다. 추가적으로 남조류의 생태학적 특성에 기반한 지속가능하고 통합적인 담수수계의 녹조 관리기법이 수립되어야 한다. 녹조를 유발하는 남조류는 척결되어야 할 생물체가 아니라, 담수 수계에 필수적인 미생물 구성원이기 때문이다.
        4,000원
        100.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
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