SON 기반 LTE 시스템에서 수신 신호 세기를 이용한 Physical Cell Identifier 할당 기법

이가희(Gahee Lee),신봉진(Bongjhin Shin),홍대형(Daehyoung Hong) 한국통신학회 2009 韓國通信學會論文誌 Vol.34 No.12

온도변화와 촉매조건에 따른 아역청탄과 아역청탄으로부터 추출한 초청정탄을 이용한 가스화 반응성 비교

이가희(Gahee Lee),윤상필(SangPhil Yoon),전영신(YongShin Jeon),김형택(Hyung-Taek Kim) 한국에너지기후변화학회 2011 에너지기후변화학회지 Vol.6 No.2

Coal is spotlighted as a top priority energy resource which will replace oil. Coal gasification can reduce amount of carbon dioxide(CO<SUB>2</SUB>), sulfur oxides(SOx) and nitrogen oxides(NOx). Also, it produces mono dioxide(CO) and Hydrogen(H<SUB>2</SUB>). However, typical-type coal gasification technology is required huge amount of energy at high temperature over 1000℃. Therefore, catalyst(K<SUB>2</SUB>CO<SUB>3</SUB>) is added to decrease operation temperature and reduce amount of energy. In this experiment, Roto ultra clean coal(UCC) and Roto original coal(OC) are used. And coal char is produced for this experiment. The experiment is progressed with 1g of coal char with potassium carbonate(K<SUB>2</SUB>CO<SUB>3</SUB>) under flowed 500ml/m of steam(H<SUB>2</SUB>O) as a reactant and 2000ml/min of nitrogen as carrier gas. With this condition, it is progressed for 1hr under different designated temperature(600, 700, 800℃) and different catalyst conditions. From those experiments, the carbon conversion ratio is calculated and compared the gasification reactivity

고객 유형 맞춤 캠핑용 하우징 서비스디자인 개발 연구

이지혜 ( Lee Jihye ),권기제 ( Kwon Kije ),조진희 ( Jo Jinhee ),박성흠 ( Park Sung-hum ),유동균 ( Yu Dong Kyun ),이가희 ( Lee Gahee ) 커뮤니케이션디자인학회 2022 커뮤니케이션 디자인학연구 Vol.78 No.-

본 연구는 한국디자인진흥원 R&D연구의 일환으로 최근 급격히 성장하고 있는 캠핑 산업에 있어서 주로 캠핑카로 인식되는 캠핑용 하우징 제품에 대한 고객의 실제적 니즈와 라이프스타일을 통한 서비스 디자인 전략을 연구하는 것을 목적으로 하였다. 연구 결과, 대부분의 캠퍼들은 캠핑준비 및 캠핑과정에 수반되는 번거로움을 해소하기 위해 캠핑카를 구매하는 것으로 드러났다. 이와 같은 캠핑용하우징 제품과 서비스에 대한 소비자의 주요니즈는 다음과 같다. 첫째, 효율적인 내부 공간 구성에 대한 수요가 파악되었다. 고객들에게는 라이프스타일과 성향에 따라 자유롭게 공간을 구성할 수 있는 제품을 필요로 한다. 둘째, 개성 표현을 할 수 있는 커스터마이징에 대한 수요가 파악되었다. 다시 말해 고객들은 개인의 성향과 라이프스타일에 맞는 제품을 구매하길 바란다. 따라서 외관 디자인 및 내부 인테리어 소재 등을 선택할 수 있도록 다양한 옵션 제공과 용도별 라인업 제품이 필요하다. 셋째, 구매과정 및 사후 관리에 있어서의 번거로움이 해소되어야 한다. 본 연구에 진행한 사용자 설문조사 결과, A/S 과정이 번거롭고, 기술 개발에 치중되어 있는 중소기업은 많은 부분 고객응대서비스에 개선이 필요하다는 답변이 다수 나타났다. 즉, 보다 고객 친화적인 서비스 제공 전략이 필요한 것이다. 따라서 고객의 번거로움이 최소화될 수 있는 통합 서비스가 제공 되어야 제품 사용 시 중도 이탈 없이 지속적인 고객층 확보가용이 할 것으로 보인다. 이와 같은 연구결과를 토대로 본 연구는 최종적으로 핵심 시나리오 5건과 서비스 플로우를 설계하여 제안하였다. 이는 향후 캠핑카 관련 서비스 개발, 혹은 고객 성향과 라이프스타일을 고려한 제품개발 시 유용하게 활용될 수 있을 것으로 기대한다. As part of the Korea Institute of Design Promotion's R&D study, the purpose of this research was to study the strategy of service design through the customer's practical needs and lifestyle for camping housing products, which are mainly recognized as camping cars in the recent rapidly growing camping industry. This studies have shown that most campers purchase camping cars to relieve the hassles accompanied by camping preparation processes. The main needs of consumers like this for such camping housing products and services are as follows. First, the demand for efficient internal space composition was identified. Customers need products that can freely organize the space according to their lifestyle and inclination. Second, the demand for customization that can express individuality was identified. In other words, customers want to purchase products that suit their individual tendencies and lifestyles. Therefore, it is necessary to provide various options and line-up products for each purpose, so that exterior design and interior materials can be picked. Third, the hassles of the purchasing process and follow-up management must be resolved. As a result of the user survey conducted in this study, many small and medium-sized enterprises focused on the technology developments & cumbersome in their after-sales service process have been replied in the majority that many parts of them need the improvement of customer service. In other words, a more customer-friendly service provision strategy is needed. Therefore, it is expected that it will be possible to continuously secure a customer base without leaving in the middle of using the product only when the integrated services that can minimize customer hassle are provided. This study finally designed and proposed five key scenarios and service flows based on these research results. This is expected to be utilized usefully in the future when developing camping car-related services or developing products that take into account customer tendencies and lifestyles.

방한 중국인 관광객이 지각하는 위험이 한국방문 참여의도에 미치는 영향

왕남(Nam Wang),이가희(Gahee Lee),유승동(Seungdong Yoo),윤덕인(Deokihn Yoon) 한국호텔외식관광경영학회 2015 호텔경영학연구 Vol.24 No.7

공공하수처리시설에서 에너지 사용현황 및 절감방안 연구

김종락 ( Jongrack Kim ),이가희 ( Gahee Rhee ),유광태 ( Kwangtae You ),김동윤 ( Dongyoun Kim ),이호식 ( Hosik Lee ) 한국물환경학회(구 한국수질보전학회) 2020 한국물환경학회지 Vol.36 No.6

This study aims to conserve and monitor energy use in public sewage treatment plants by utilizing data from the SCADA system and by controlling the aeration rate required for maintaining effluent water quality. Power consumption in the sewage treatment process was predicted using the equipment’s uptime, efficiency, and inherent power consumption. The predicted energy consumption was calibrated by measured data. Additionally, energy efficiency indicators were proposed based on statistical data for energy use, capacity, and effluent quality. In one case study, a sewage treatment plant operated via the SBR process used∼30% of energy consumed in maintaining the bioreactors and treated water tanks (included decanting pump and cleaning systems). Energy consumption analysis with the K-ECO Tool-kit was conducted for unit processing. The results showed that about 58.7% of total energy consumed was used in the preliminary and biological treatment rotating equipment such as the blower and pump. In addition, the energy consumption rate was higher to the order of 19.2% in the phosphorus removal process, 16.0% during sludge treatment, and 6.1% during disinfection and discharge. In terms of equipment energy usage, feeding and decanting pumps accounted for 40% of total energy consumed following 27% for blowers. By controlling the aeration rate based on the proposed feedback control system, the DO concentration was reduced by 56% compared pre-controls and the aeration amount decreased by 28%. The overall power consumption of the plant was reduced by 6% via aeration control.

재난 속 허위정보 피해예방을 위한 기술방안

최동진(Dongjin Choi),이가희(Gahee Lee) 한국콘텐츠학회 2021 한국콘텐츠학회 종합학술대회 논문집 Vol.2021 No.8

Isoquercitrin 함유 연꽃잎 추출물의 피부주름개선 효능 연구

문은정 ( Eunjung Moon ),전준명 ( Junmyeong Jeon ),이가희 ( Gahee Lee ),백민영 ( Minyoung Baik ),이대우 ( Dae Woo Lee ) 대한화장품학회 2018 대한화장품학회지 Vol.44 No.2

본 연구에서는 제1형 프로콜라겐 분비량 측정을 통해 피부 주름개선 효과가 있는 천연물을 검색하던 중, 연꽃잎추출물(Nelumbo nucifera leaves extract, NLE)이 가장 우수한 효능을 나타냄을 확인하였다. 고압액체크로마토그래피로 NLE를 분석한 결과 isoquercitrin이 함유되어 있었으며, isoquercitrin도 normal human dermal fibroblast (NHDF)에서 제1형 프로콜라겐의 분비를 촉진한다는 것을 확인할 수 있었다. 또한 NLE와 isoquercitrin은 자유 라디컬 소거 활성을 가지고 있었으며, 특히 isoquercitrin은 인간 피부유래 세포주인 HaCaT 및 NHDF에서 활성산소종의 생성을 억제하고 총항산화능을 증가시켰다. 최종적으로 본 연구팀은 isoquercitrin의 함유량을 높이기 위해 정제한 NLE를 1.7% 함유한 크림(isoquercitrin 51 ppm 함유)을 제조하여 눈가의 주름개선 효과를 평가하였다. 30 ~ 65세의 한국인 여성 22명을 대상으로 얼굴의 한쪽 면엔 NLE 함유 크림을, 그리고 다른 한쪽 면엔 대조제품을 매일 2회씩, 8주간 연속 사용하도록 하였다. 그 결과 NLE 함유 크림을 사용하였을 때 피부자극이 발견되지 않았으며, 대조제품과 비교하여 통계적 유의성 있게 눈가의 주름을 감소시키는 것을 확인할 수 있었다. 본 연구결과는 NLE 및 isoquercitrin이 우수한 콜라겐 생성 촉진 및 항산화 효능을 가지며, isoquercitrin 함유 NLE는 안전한 천연 주름개선 화장품 소재로 적용 가능하다는 것을 시사한다. In this study, we conducted research to find anti-wrinkle skin care ingredients from natural sources via the measurement of procollagen type 1 levels in the medium of normal human dermal fibroblast (NHDF) and found that a Nelumbo nucifera leave extract (NLE) was as the best effective ingredient. By the high performance liquid chromatography analysis, we confirmed isoquercitrin was one of the main compounds of NLE. Moreover, it also increased the procollagen type 1 production without cytotoxicity of NHDF. NLE and isoquercitrin exerted free radical scavenging activity. Especially, isoquercitrin exhibited strong intracellular antioxidant capacity in human skin-derived cells, HaCaT and NHDF. Finally, we performed clinical test for the inhibitory effect of NLE on skin wrinkle formation. A randomized study was conducted in 22 healthy female volunteers, aged between 30 and 65 yrs, with moderate to moderately severe facial wrinkles. Volunteer applied a 1.7% NLE cream (isoquercitrin 51 ppm) and a control cream at each facial side (left/right) twice daily for 8 weeks. The 1.7% NLE cream improved skin roughness through reducing the wrinkle of the craw’s feet significantly without any skin side effect. Our results demonstrate that NLE and isoquercitrin can increase the collagen production and exert antioxidant activity. Therefore, we expect that the new non-toxic herbal extract, isoquercitrin-containing NLE will be interesting natural ingredient of cosmetics with anti-wrinkle efficacy.

입력 전압 변화에 따른 공진형 무선전력전송 효율 분석

박희정(Heejeong Park),신중권(Jungkwon Shin),배진우(Jinwoo Bae),김종영(Jongyoung Kim),이가희(Gahee Lee ) 한국자동차공학회 2016 한국자동차공학회 학술대회 및 전시회 Vol.2016 No.11

무선전력전송을 통한 REAR LAMP 전원 공급 시스템

박희정(Heejeong Park),배진우(Jinwoo Bae),신중권(Jungkwon Shin),김종영(Jongyoung Kim),이가희(Gahee Lee) 한국자동차공학회 2016 한국자동차공학회 학술대회 및 전시회 Vol.2016 No.11

In this paper, 15W wireless power transmission system for REAR LAMP of car using the magnetic resonance is proposed. This system is composed up Power transmitter installed OUT-SIDE LAMP in body of car and Power Receiver installed IN-SIDE LAMP in Trunk of car. The wireless power block consists of Class D Type Amp, 300kHz magnetic resonator of spiral structure and full bridge receiver using diode. Especially, the PTU(Power Transmit Unit) includes voltage and signal input control circuit named “TAIL”, “STOP”, TURN”, “BACK-CUP”, as well as wireless duplex communication for PRU(Power Receiver Unit) output control. We expect the new design of REAR LAMP in car by using this system that electrical segregation of trunk in car.