Lot Planning & Scheduling in the Integrated Steelmaking Process

Hyungwoo Park,Yushin Hong 대한산업공학회 2002 대한산업공학회 춘계학술대회논문집 Vol.2002 No.5

Lot Planning & Scheduling in the Integrated Steelmaking Process

Park, Hyungwoo,Hong, Yushin 한국경영과학회 2002 한국경영과학회 학술대회논문집 Vol.- No.1(1)

Steel industry is the most capital intensive and the largest energy consuming industry, which operate huge and complex facilities to supply various steel products as the primary materials to almost every manufacturing industry. Major steel products are hot-rolled and cold-rolled coils, plates, and wires that are produced through molten iron making, molten steel making, casting, and rolling. Each process runs in batch between setups and the specifications of batch are different with each other. High energy consuming and heavy material handling require careful synchronization of processes, as well. Considering the synchronization of processes, the lot planning and scheduling problem in the integrated steelmaking process covers the roll grouping with given casts, the sequencing of rolls over time, and the machine assignment and time scheduling of charges and casts. The problem is investigated by dividing it into two cases whether single or parallel machines at the molten steel making and the continuous casting processes. Problem descriptions and solution approaches of each instance are introduced. To test their performance and conformity, implementation of the algorithms and numerical experiments are carried out with real world and constructed data sets.

A Study on Annoyance Degradation to Indoor Noise in the Village Bus

Hyungwoo Park(박형우),Myung-jin Bae(배명진) 한국컴퓨터정보학회 2017 한국컴퓨터정보학회 학술발표논문집 Vol.25 No.1

Improvement of Sound Quality of Voice Transmission by Finger

Hyungwoo Park 국제문화기술진흥원 2019 International Journal of Advanced Culture Technolo Vol.7 No.2

In modern society, people live in an environment with artificial or natural noise. Especially, the sound that corresponds to the artificial noise makes the noise itself and affects each other because many people live and work in the city. Sounds are generated by the activities and causes of various people, such as construction sites, aircraft, production machinery, or road traffic. These sounds are essential elements in human life and are recognized and judged by human auditory organs. Noise is a sound that you do not want to hear by subjective evaluation, and it is a loud sound that gives hearing damage or a sound that causes physical and mental harm. In this study, we introduce the method of stimulating the human hearing by finger vibration and explain the advantages of the proposed method in various kinds of a noise environment. And how to improve the sound quality to improve efficiency. In this paper, we propose a method to prevent the loss of hearing loss and the transmission of sound information based on proper signal to noise ratio when using portable IT equipment in various noise environments.

Improvement of Sound Quality of Voice Transmission by Finger

Park, Hyungwoo The International Promotion Agency of Culture Tech 2019 International Journal of Advanced Culture Technolo Vol.7 No.2

In modern society, people live in an environment with artificial or natural noise. Especially, the sound that corresponds to the artificial noise makes the noise itself and affects each other because many people live and work in the city. Sounds are generated by the activities and causes of various people, such as construction sites, aircraft, production machinery, or road traffic. These sounds are essential elements in human life and are recognized and judged by human auditory organs. Noise is a sound that you do not want to hear by subjective evaluation, and it is a loud sound that gives hearing damage or a sound that causes physical and mental harm. In this study, we introduce the method of stimulating the human hearing by finger vibration and explain the advantages of the proposed method in various kinds of a noise environment. And how to improve the sound quality to improve efficiency. In this paper, we propose a method to prevent the loss of hearing loss and the transmission of sound information based on proper signal to noise ratio when using portable IT equipment in various noise environments.

기능성 MA 포장재가 ‘후지’ 사과의 신선도에 미치는 영향

박형우(HyungWoo Park),김동만(Dongman Kim) 한국식품영양과학회 2000 한국식품영양과학회지 Vol.29 No.1

기능성 필름을 코팅한 골판지 상자에 사과를 저장하면서 품질유지 상태를 조사하고자 대조구로 기존에 유통 중인 골판지 상자와 두께 0.03, 0.05 ㎜의 LDPE필름(30LD와 50LD)과, 두께 0.03 ㎜, 0.05 ㎜의 기능성MA 필름을 골판지 상자에 코팅한(30CE와 50CE) 후 이 상자에 후 지사과를 15 ㎏씩 포장하여 5℃에 75일간 저장하면서 신선도 변화를 비교 연구하였다. 중량 감소는 저장 75일 후 대조구는 2.7%, LD와 CE 포장구들은 0.2~0.5% 감소했다. 경도는 대조구보다는 필름포장구들에서 변화가 적었고 LD보다는 CE 포장구에서 변화가 더 적게 나타났다. 비타민 C 함량은 초기의 3.67 ㎎%에서 대조구는 42%, LD포장구들은 31~29%, CE 포장구들은 24~22%가 감소하였다. 산도 및 가용성 고형분의 경우 대조구가 필름포장구들에서 변화가 심했으며, 필름포장구들 중에서는 LD포장구보다 CE 포장구에서 변화가 적게 나타났으며, 부패도 대조구보다는 LD와 CE 포장구에서 적게 나타났다. To investigate the effect of packaging condition on functional MA films laminated (30CE, 50CE), cor-rugated paperboard box (control), 30LDPE, and 50LDPE pouches on the freshness extension of Fuji apples, the weight loss, firmness, total ascorbic acid, titratable acidity, soluble solids content and appearence were evaluated at 5℃ after 75 days. Weight loss of 30CE and 50CE, and 30LD and 50LD was 0.4 to 0.5%, and 0.2%, but control was 2.7%. Firmness in film packages was higher than that of control, and CE packagings were higher than LD. Total ascorbic acid content of Fuji apple in control after 75 days was 2.12 mg%, that of control was decreased by 42%, those of LD packagings were 31% and 29%, and those of CE were 24% and 22%. Titratable acidity and soluble solids content in control changed more than that of MA film packagings. Overall appearence of ‘Fuji’ apples in CE packagings was better than that of control.

Graphene–nanowire hybrid structures for high-performance photoconductive devices

Lee, Hyungwoo,Heo, Kwang,Park, Jaesung,Park, Yongju,Noh, Seunguk,Kim, Kwang S.,Lee, Changhee,Hong, Byung Hee,Jian, Jikang,Hong, Seunghun The Royal Society of Chemistry 2012 Journal of materials chemistry Vol.22 No.17

<P>Graphene–CdS nanowire (NW) hybrid structures with high-speed photoconductivity were developed. The hybrid structure was comprised of CdS NWs which were selectively grown in specific regions on a single-layer graphene sheet. The photoconductive channels based on graphene–CdS NW hybrid structures exhibited much larger photocurrents than graphene-based channels and much faster recovery speed than CdS NW network-based ones. Our graphene–CdS NW structures can be useful because they were much faster than commercial CdS film-based photodetectors and had photocurrents large enough for practical applications.</P> <P>Graphic Abstract</P><P>We have developed a photoconductive channel based on graphene–CdS nanowire hybrid structures which exhibited large photocurrent and fast recovery speed. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2jm16565a'> </P>

포장재가 ‘취청’ 오이의 저장 중 품질에 미치는 영향

박형우(HyungWoo Park),김동만(Dongman Kim) 한국식품영양과학회 2000 한국식품영양과학회지 Vol.29 No.2

기능성 MA필름을 생산하여 이를 골판지 상자의 내부에 첨합시킨 FC상자의 활용기능성을 조사하고자 골판지상자와 기능성 MA필름을 골판지 상자 내부의 1면당 3곳씩 첨합시킨 FC 포장 상자 및 LD 파우치에 오이를 10 kg씩 포장하여 20℃에 7일간 저장하면서 품질변화를 조사한 결과, FC 상자와 LD 파우치는 대조구보다는 중량감소율이 현저히 낮았으며 비타민 C 함량도 대조구보다 10%높게 유지되고 있었다. 클로로필도 대조구보다 16% 정도 더 높게 유지되고 있었으며 경도도 비슷한 경향을 나타내 생산지에서 MA필름을 사용하여 포장작업시 편리성과 신선도 유지기능을 부여코자 골판지상자에 기능성MA필름을 첨합한 FC 포장재를 ‘취청’ 오이 포장용으로 활용할 수 있다고 사료되었다. To investigate the effects of packaging films (functional MA films/FC30, FC50, MA film/0.03 mm LDPE, corrugated paperboard box/control) weight loss, firmness, total ascorbic acid, chlorophill and overall appearence were evaluated. Weight loss of cucumbers packed with FC30 and FC50 at 20℃ after 7 days were 1.0 and 0.6%, that of the control was 2.9%, those of LDPE was 0.5%. The firmness of FC30, FC50 and LD was higher than that of the control. Total ascorbic acid contents (TAA) of cucumbers packed with control, LD, FC30 and FC50 box were 9.96, 10.86, 11.37 and 11.29 mg% after 7 days. TAA of FC box was 10% higher than that of the control. Chlorophill content of FC boxes wase 16% higher than of the control. Overall appearence of cucumber packed with FC boxes was better than that of the control.

Expanded Polystyrene Foam Box로 포장한 애호박의 신선도 유지 효과

박형우(HyungWoo Park),박종대(JongDae Park),이명훈(Myung Hoon Lee) 한국식품영양과학회 2000 한국식품영양과학회지 Vol.29 No.1

EPS 포장상자에 호박을 포장하여 신선도 유지효과 기능이 있는지의 여부를 분석코자 20℃에 저장하면서 신선도 유지효과를 비교하였다. 포장은 골판지상자와 0.02와 0.04 ㎜ 두께의 LDPE필름, EPS 상자로 포장하였다. 저장 7일후 중량감소는 대조구는 5.9%, EPS 상자는 1.1%의 중량감소가 나타났고, 비타민C도 EPS 포장구가 대조구 보다 11.1% 더 높게 유지 되고 있었고 클로로필은 18.9%높게 유지되고 있었다. 경도도 EPS와 LDPE포장구가 대조구 보다 약간 높게 유지되고 있었으며, 부패는 대조구는 1~2개과가 발생했으나 EPS 포장구는 발생하지 않았다. 이상의 결과로부터 EPS 포장상자는 기존의 골판지상자 보다 신선도 유지효과가 우수하였다. The effects of packaging conditions on freshness extension of squash (Cucurbita moscata) were inves-tigated during 7-day storage at 20℃. Weight loss of squash packed with corrugated paperboard box (control)was 5.5%, and those of LDPE (low density polyethylene, φ0.02 ㎜), LDPE (φ0.04 ㎜) film and EPS (expanded polystyrene) box were 0.9%, 0.8%, and 1.1%, respectively. Firmness of EPS was 11% higher than that of control, chlorophill content of squash packed with EPS box was 18.9% higher, and total ascor-bic acid content of squash packed with EPS box was 29.4% higher than that of control. Quality of packed squash was not different between EPS packages and LDPE packages. Decay of control was 1~2 pieces per box, but was not found in the LDPE, EPS box. Preferences in overall appearences of LDPE, EPS box was better than those of control.

철강 Mini Mill 에서의 효율적인 작업 단위 편성

박형우(Hyungwoo Park),홍유신(Yushin Hong),장수영(Soo Young Chang),황삼성(Samsung Hwang) 대한산업공학회 1998 대한산업공학회지 Vol.24 No.4