• 한국환경보건학회지
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• 제44권3호
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• pp.275-282
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• 2018

Objective: Since certain chemicals are widely applied in a variety of consumer products, exposure via simultaneous use of multiple consumer products can put human health at risk. For this reason, use patterns of consumer products are an important factor inhuman health risk assessment. The aim of this study is to investigate co-use patterns of air-fresheners and deodorizers in Korea in order to estimate potential cumulative exposure. Methods: To collect the information on use patterns of air-fresheners and deodorizers, ten air-fresheners and 14 deodorizers were selected. A total of 3,000 participants were recruited and asked through on line questionnaires whether they had simultaneously used the selected air-fresheners and deodorant products in their daily lives. Results: Among the 3,000 participants, 45.6% had used more than two air fresheners and 46.3% used more than two deodorizers. The most common types of air fresheners used concurrently include liquid and candle types for indoor environments, while those of deodorizers were fabric trigger sprays and refrigerator gels. In addition, 73.7% used more than two products without product categories. Fabric trigger sprays were contained in all of the high-ranking product combinations. Conclusions: This study showed that many consumers concurrently used air-fresheners and deodorizers in their daily routines. For accurate exposure assessment, co-use patterns of consumer products should be further investigated.

• 한국레이저가공학회지
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• 제11권1호
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• pp.32-35
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• 2008

In the remote welding system using $CO_2$ laser, laser beam can be rapidly transferred to a workpiece by moving mirrors of scanner system. So, it makes reducing the cycle time of welding process. We can also use and apply various patterns of weld beads by linear controlled mirrors. But most of the domestic car makers have usually applied use stitch-shaped weld bead. In that case, we don't have the merit of remote welding system efficiently. Therefore, in this paper, we investigated the characteristic of weld strength according to patterns of weld bead on $CO_2$ laser welding. And we also studied the relationship between shape of weld bead and value of tensile load.

• Journal of Information Processing Systems
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• 제14권5호
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• pp.1254-1271
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• 2018

Keyphrase extraction is one of fundamental natural language processing (NLP) tools to improve many text-mining applications such as document summarization and clustering. In this paper, we propose to use two novel techniques on the top of the state-of-the-art keyphrase extraction methods. First is the anti-patterns that aim to recognize non-keyphrase candidates. The state-of-the-art methods often used the rich feature set to identify keyphrases while those rich feature set cover only some of all keyphrases because keyphrases share very few similar patterns and stylistic features while non-keyphrase candidates often share many similar patterns and stylistic features. Second one is to use the dependency graph instead of the word co-occurrence graph that could not connect two words that are syntactically related and placed far from each other in a sentence while the dependency graph can do so. In experiments, we have compared the performances with different settings of the graphs (co-occurrence and dependency), and with the existing method results. Finally, we discovered that the combination method of dependency graph and anti-patterns outperform the state-of-the-art performances.

• 한국환경보건학회지
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• 제48권4호
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• pp.206-215
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• 2022

Background: Fragrance substances in consumer products can cause adverse health effects such as contact allergy. In South Korea, consumer chemical products must list 26 known fragrance allergens on product labels when they contain more than 0.01%. Fragrance substances are mostly used in combination, so co-exposure can occur via use of a consumer chemical product. Co-exposure to fragrance allergens may show a synergistic effect on the human body. Objectives: The aims of the study were to analyze the characteristics of fragrance allergens in consumer chemical products available on public websites and to identify the co-occurrence patterns of fragrance allergens. Methods: The chemicals in 1,443 ingredient disclosures for consumer chemical products were collected through the Ecolife database. The 26 labelled fragrance allergens were identified by category of consumer chemical product. The co-occurrence patterns of the 26 labelled fragrance allergens were analyzed by frequent pattern mining. The unlabelled fragrance allergens presented by European Union Scientific Committee on Consumer Safety were also identified. Results: Consumer chemical products contained an average of 5.3±4.2 substances among the 26 labelled fragrance allergens. More than 85% of air fresheners, deodorizing agents, and fabric softeners contained at least one of the 26 labelled fragrance allergens. The most frequently contained fragrance allergens were limonene (50.5%), linalool (49.9%), hexyl cinnamal (34.0%), and citronellol (28.3%). 16.7% of consumer chemical products showed a co-occurrence of limonene, linalool, hexyl cinnamal, and citronellol. Thirty-eight unlabelled fragrance allergens were found in the consumer chemical products, with hexamethylindanopyran (25.2%) being the most frequently contained substance. Conclusions: The characteristics and co-occurrence patterns of 26 labelled fragrance allergens would be useful information for the management of co-exposure to fragrance allergens in consumer chemical products. It is necessary for attention to be paid to unlabelled fragrance allergens.

• 한국산학기술학회논문지
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• 제13권3호
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• pp.1370-1376
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• 2012

본 연구에서는 지구단위 내 교통부문에서 다양한 도시설계 및 교통정책의 적용에 따른 $CO_2$의 배출량 효과를 분석해보고자 하였다. 이를 위해 가상네트워크(Toy Network)를 설정하고 토지이용패턴과 교통정책을 접목한 19개의 시나리오를 가정한 후 교통수요 예측 프로그램인 EMME3를 이용하여 $CO_2$ 발생량을 산정하고 비교하였다. 그 결과 총 $CO_2$ 배출량이 가장 많이 감소한 정책은 지구의 중간부를 개발하면서 동시에 내부의 2차로 도로는 차량 통행을 금지시키고 보행자 천국을 만드는 것이었다. 총 $CO_2$량이 가장 많이 발생된 그룹은 교통공학에서 일반적으로 인식되어 왔던 적절한 도로위계에 따른 도로망 구성 및 접근통제 조절 정책이었다. 따라서 지구설계시 도로망 구성 및 접근통제는 세밀한 연구를 통해 실행되어야 할 것임을 알게 되었다.

• 한국산학기술학회논문지
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• 제14권7호
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• pp.3508-3517
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• 2013

지구(district)는 도시를 형성하는 기본 단위로 모든 도시활동이 시작되는 장소이다. 따라서 본 연구에서는 지구단위에서의 교통과 토지이용패턴의 결합 형태에 따른 270개의 시나리오를 가정하고 $CO_2$ 배출량을 분석한 후 $CO_2$ 배출량을 최소화하는 토지이용-교통모형을 작성하고자 하였다. 그 결과 균등 또는 외곽을 고밀도로 개발하는 토지이용패턴이 지구의 중간부나 1개 중앙존만을 개발하는 것보다 $CO_2$ 배출량 감소에 유리한 것으로 파악되었다. $CO_2$ 배출량 감소에 가장 영향을 많이 주는 것은 교통수요관리정책으로, 특히 개발밀도가 높은 상태일수록 $CO_2$를 감소시키기 위해서 교통수요관리는 필수적인 것으로 판단되었다. 고밀개발이 아닌 경우에 주어진 가상 네트워크에서는 2차로도로에 차량통행금지를 시키고 보행자도로로 전환시킬 경우 $CO_2$ 배출량을 감소시킬 수 있음을 알게 되었다. 한편, 제시된 토지이용-교통 회귀모델은 지구설계시 $CO_2$ 배출량을 줄이기 위한 최적대안 선정시 도움을 줄 수 있을 것으로 사료된다.

• ETRI Journal
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• 제26권5호
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• pp.467-474
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• 2004

In a High Altitude Platform (HAP) cellular communications network, each cell may be served by a dedicated spot-beam antenna. The antennas' beam properties and their spatial overlap control the co-channel interference. In prior literature, radiation patterns have been approximated by a main lobe followed by a constant sidelobe floor. A network of 121 cells has been studied and the method is here extended to the use of more realistic radiation patterns based on the theoretical aperture antenna patterns. This allows for the comparison of the effect of different aperture field tapers, which lead to reduced sidelobe levels and hence higher system capacity but also a more massive antenna payload.

• 대한산업공학회지
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• 제42권2호
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• pp.96-111
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• 2016

Effort to reduce energy consumptions or CO2 emissions is global trend. To follow this trend, spatial studies related to characteristics affecting energy consumptions or CO2 emissions have been conducted, but only with the focus on spatial dependence, not on spatial heterogeneity. The aim of this study is to investigate spatial heterogeneity patterns of CO2 emission based on socio-economic factors, land-use characteristics and traffic infrastructure of Seoul city. Geographically Weighted Regression (GWR) analysis was performed with 423 administrative district data in Seoul. The results suggest that population and employment densities, road density and railway length in most districts are found to have positive impact on the CO2 emissions. Residential and green area densities also have the highest positive impact on CO2 emissions in most districts of Gangnam-gu. The resulting model can be used to identify the spatial patterns of CO2 emissions at district level in Seoul. Eventually it can contribute to local energy policy and planning of metropolitan area.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권9호
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• pp.2982-3003
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• 2014

With the explosive deployment of the wireless communications technology, the increased QoS requirement has sparked keen interest in network planning and optimization. As the major players in wireless network optimization, the BS's resource utilization and mobile user's QoS can be improved a lot by the load-balancing technology. In this paper, we propose a load-balancing strategy that uses Coordinated Multiple Points (CoMP) technology among the Base Stations (BS) to effectively extend network coverage and increase edge users signal quality. To use universally, different patterns of load-balancing based on CoMP are modeled and discussed. We define two QoS metrics to be guaranteed during CoMP load balancing: call blocking rate and efficient throughput. The closed-form expressions for these two QoS metrics are derived. The load-balancing capacity and QoS performances with different CoMP patterns are evaluated and analyzed in low-dense and high-dense traffic system. The numerical results present the reasonable CoMP load balancing pattern choice with guaranteed QoS in each system.

• 한국레이저가공학회지
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• 제11권1호
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• pp.1-6
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• 2008

We proposed new light guide panel (LGP) fabrication method exploiting laser-processed inner scatterers and surface pattern. The proposed method has achieved LGP performance improvement in both brightness and uniformity. The inner scatterers and surface pattern of grid type were fabricated with a 2nd harmonic Nd:YAG pulse laser engraving system and a $CO_2$ laser scanning system, respectively. In the implementation of LGP, inner scatterers was arranged in accordance with linear or curved pattern with changing density and surface pattern was engraved on the surface of an inner-scatterers embedded LGP. The increase of scatterers' density and the use of surface patterns in both linear and curved pattern provided high luminance and uniformity enhancement. While thecurved pattern incorporated with increased scatterers' density and surface patterns yielded brightness improvement with preserving good uniformity, the linear pattern showed highly localized brightness near the light entrance of the LGP. We can also observe that the uniformity was mainly determined by pattern of inner scatterers, and the brightness was improved by the higher density and the utilization of surface patterns. From the results, the use of laser-processed inner and surface patterns can be a potential alternative for efficient and simple LGP fabrication method.