• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.9C
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• pp.913-921
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• 2005

A complex bandpass sampling technique can provide a more flexible architecture for designing a software- defined radio(SDR) system, because it has several advantageous features of larger sampling range and lower minimum sampling frequency than a real bandpass sampling method. In spite of the potential advantages of the complex bandpass sampling, solid investigation for the direct downconversion of multiple signals by the complex sampling theory has not been reported yet. Thus, we propose in this paper a novel scheme for the downconversion of multiple signals using the complex bandpass sampling, and develop the formulae related to the complex bandpass sampling for practical usage, such as the valid sampling range, the intermediate frequency (If), and the minimum sampling frequency of the downconversion of multiple RE signals. Such derived formulae are verified from simulations.

• Annual Conference on Human and Language Technology
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• 2018.10a
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• pp.316-320
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• 2018

복합명사는 둘 이상의 말이 결합된 명사를 말하며 문장에서 하나의 단어로 간주된다, 그러나 맞춤법 및 띄어쓰기 검사나 정보검색의 색인어 추출, 기계번역의 미등록어 추정 등의 분야에서는 복합명사를 구성하는 개별 단어를 확인할 필요가 있다. 이 과정을 복합명사 분해라고 한다. 복합명사를 분해하는 방법으로 크게 규칙 기반 방법, 통계 기반 방법 등이 있으며 본 논문에서는 규칙을 기반으로 최소한의 통계 정보를 이용하는 방법을 제안한다. 본 논문은 4개의 분해 규칙을 적용하여 분해 후보를 생성하고 분해 후보들 중에 우선순위를 정하여 최적 후보를 선택하는 방법을 제안한다. 기본 단어(명사)로 트라이(trie)를 구축하고 구축된 트라이를 이용하여 양방향 최장일치를 적용하고 음절 쌍의 통계정보를 이용해서 모호성을 제거한다. 성능을 평가하기 위해 70,000여 개의 명사 사전과 음절 쌍 통계정보를 구축하였고, 이를 바탕으로 복합명사를 분해하였으며, 분해 정확도는 단어 구성비를 반영하면 96.63%이다. 제안된 복합명사 분해 방법은 최소한의 데이터를 이용하여 복합명사 분해를 수행하였으며 트라이 자료구조를 사용해서 사전의 크기를 줄이고 사전의 검색 속도를 개선하였다. 그 결과로 임베디드 시스템과 같은 소형 기기의 환경에 적합한 복합명사 분해 시스템을 구현할 수 있었다.

• Journal of Convergence for Information Technology
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• v.8 no.5
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• pp.199-204
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• 2018

The concept of the Independent Living (IL) movement has been affected on recent disability public policy to enhance the right of consumers with disabilities, as well as to eliminate the barriers on employment. The IL movement emphasizes the empowerment and autonomy of consumer with disabilities to achieve their rights in educational, social, and employ environment. This paper presents three vocational rehabilitation(VR) services that affect consumers with disabilities based on the values of the Independent Living movement, and recommend some practical strategies. These VR services include the collaboration projects between the VR agencies and Independent Living Centers, the intervention programs to enhance the self determination or informed choice as a consumer, and the projects to strengthen the relationship between consumers with disabilities and their service providers.

• Journal of Convergence for Information Technology
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• v.10 no.10
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• pp.80-87
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• 2020

The purpose of this study was to compare in antiseptic effect between povidone-iodine and chlorhexidine-ethanol for laparoscopic cholecystectomy on the port site. A total of 46 patients admitted to surgery at one university hospital in Seoul were included in the study. A study group was randomly assigned using a random number table. The antiseptic effect was evaluated and compared to povidone-iodine and chlorhexidine-ethanol by using a culture and identification of bacteria, measurement of the number of bacteria (CFU/ml) and incidence of surgical site infection. Our results show that povidone-iodine and chlorhexidine-ethanol have no statistically significant difference in the incidence rate of bacteria after 3 minutes of disinfection and before removal of the trocar and in the number of bacteria and the incidence of surgical site infection. Thus, in order to select an efficient and appropriate skin antiseptics, we suggest that it is necessary to consider not only the disinfectant effect but also cost and convenience. In this research, our results about effect and usage of skin antiseptics can be used as basic data and educational resource, and this is expected to improve comprehension of skin antiseptics.

• Polymer(Korea)
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• v.25 no.6
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• pp.789-795
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• 2001

In order to recover nickel ion from waste water containing heavy metals, the PAN fibrous ion-exchanger with primary, secondary amine groups and carboxyl group was synthesized by acid and base hydrolysis. The hydrolysis yield of PAN fiber in acid solution was higher than base solution. The swelling ratio and ion-exchange capacity of PAN fiber which was synthesized in 1N $H_2SO_4$ solution at $80^{\circ}C$ for 7 hrs appeared 71.2% and 1.95 meq/g respectively. We investigated that the adsorption of nickel ion was approached 1.44 meq/g at 50 min and the maximum adsorption capacity of ion-exchanger was 2.48 meq/g. We confirmed that the $Ni^{+2}$ adsorption ability of the synthesized PAN fibrous ion-exchanger in this study is excellent.

• Polymer(Korea)
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• v.25 no.3
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• pp.311-317
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• 2001

In this study, we synthesized bead-type GMA-DVB copolymer using glycidylmethacrylate (GMA) with high reactivity and hydrophilicity. Macrorecticular anion exchanger containing the trimethylammonium group were then prepared by amination with trimethylammonium chloride. We observed that the size of $NO_3^-$ is smaller than that of $SO_4^{2-}$ which disturb $NO_3^-$ removal in most of coexistent anions in ground water. Thus we investigated selective affinity for $NO_3^-$ and properties of individual ion exchangers with various DVB content. For each resins, we confirmed formation of copolymer by FT-IR spectrometer and investigated ion exchange capacity, swelling ratio, the amination yield and the effect with degree of crosslinking on adsorbability for nitrate. When amount of DVB is 4 wt%, amination yield, ion exchange capacity and swelling ratio was 384.3%, 3.25 meq/g and 77.1%, respectively. In these result, it can found that synthetic optimal condition is 4 wt% DVB content for monomer.

• Nuclear Engineering and Technology
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• v.1 no.1
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• pp.17-22
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• 1969

English sole (Parophrvs vetulus) fillets packaged in polymylar bags were irradiated at 500 Krad, using a Cobalt-60 irradiator and the accumulation of spoilage indices substances and bacterial growth in the irradiated and unirradiated samples were measured during 36 days of storage at 0-2$^{\circ}C$. A casein agar plate technique was developed for a direct enumeration of proteolytic bacterial population, thus enabling the determination of relative proportion of proteolytic bacteria in the total microflora at each storage interval. Irradiation at 500 Krad resulted in a ten fold reduction of microflora and throughout the storage period the level of microflora lagged behind that of the unirradiated, by as much as one thousand fold. This was accompanied by a remarkable suppression of TVB and TMA accumulation in the irradiated, never reaching a spoliage level. Proteolytic bacterial population also was reduced to below one per cent of the total viable count and remained so throughout the storage period, while proteolytic bacteria in the unirradiated increased proportionately with the storage, comprising 85.5% of the total microflora by the twenty-second day. This selective removal of proteolytic bacteria must account for the reduced rate of proteolysis occurred in the irradiated during the storage.

• Journal of the Mineralogical Society of Korea
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• v.29 no.2
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• pp.35-45
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• 2016

Clays, which are abundant in nature and eco-friendly, have been utilized throughout human history due to their characteristic physicochemical properties. Recently, a variety of clays such as montmorillonite, kaolinite, sepiolite and layered double hydroxide with or without chemical modification have been extensively studied for potential application in industries. Clays that possess a large specific surface area, high aspect ratio, nanometer sized layer thickness and controllable surface charge could be utilized as polymer fillers after appropriate chemical modifications. These modified clays can improve mechanical and gas barrier properties of polymer materials but also provide sustained antibacterial activity to polymer films. Furthermore, engineered clays can be utilized as scavengers for chemical or biological pollutants in water or soil, because they have desirable adsorption properties and chemical specificity. In this review, we are going to introduce recent researches on engineered clays for potential applications in future industries such as food packaging and environmental remediation.

• Journal of the Korean Arthroscopy Society
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• v.3 no.1
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• pp.35-39
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• 1999

The authors introduce an operative technique which is simple and effective for the treatment of the large prepatellar bursitis, avoiding problems by the conventional open technique such as tender scar, infection and recurrence. We treated three cases of the large refractory prepatellar bursitis caused by acute direct trauma. Bursectomies were performed by using an arthroscope and percutaneous multiple sutures were applied to the overlying skin with mattress fashion. There were no complications after treatment over one year follow-up. We suggest that this technique is very useful, greatly minimizes the chance of recurrence and reduces the possibility of post-operative infection.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.47 no.6
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• pp.33-42
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• 2010

This research propose a practical guidance system considering ocean currents in real sea operation. Optimality of generated path is not an issue in this paper. Way-points from start point to possible goal positions are selected by experienced human supervisors considering major ocean current axis. This paper also describes the implementation of a precise underwater navigation solution using multi-sensor fusion technique based on USBL, GPS, DVL and AHRS measurements in detail. To implement the precise, accurate and frequent underwater navigation solution, three strategies are chosen. The first one is the heading alignment angle identification to enhance the performance of standalone dead-reckoning algorithm. The second one is that absolute position is fused timely to prevent accumulation of integration error, where the absolute position can be selected between USBL and GPS considering sensor status. The third one is introduction of effective outlier rejection algorithm. The performance of the developed algorithm is verified with experimental data of mine disposal vehicle and deep-sea ROV.