• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.40 no.5
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• pp.27-35
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• 2008

In order to determine the most appropriate recycling line to treat old corrugated container (OCC) to substitute unbleached kraft pulp (UKP) for the manufacture of kraft paper, three recycling lines were evaluated in pilot scale tests. The recycling line consisting of kneading, flotation, washing, dispersion and screening steps was able to produce pulp with acceptable appearance. Kneading was shown to be more efficient treatment to reduce specks than dispersion. In addition, 0.2 mm slot screen was very effective to remove specks. Severe damages on fiber morphology such as shortening of fiber and formation of fines were not observed during mechanical treatments such as kneading and dispersion. Most of strength properties of the kraft paper produced with the recycled pulp were found to be slightly increased after treated in the recycling lines.

• Journal of KIISE:Software and Applications
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• v.26 no.8
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• pp.974-987
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• 1999

이동 컴퓨팅 환경에서 자주 접근하는 데이터에 대한 캐싱은 무선 채널의 좁은 대역폭에서 경쟁을 줄일 수 있는 유용한 기술이다. 그러나, 트랜잭션 캐시 일관성을 지원하는 전통적인 클라이언트/서버 전략은 클라이언트와 서버간에 많은 양의 통신을 필요로 하기 때문에 이동 클라이언트/서버 컴퓨팅 환경에서는 적절하지 않다. 본 논문에서는 브로드캐스트-기반 캐시 무효화 정책을 사용하면서 트랜잭션 캐시 일관성을 지원하는 OCC-UTS (Optimistic Concurrency Control with Update TimeStamp) 프로토콜을 제안한다. 접근한 데이터에 대한 일관성 검사 및 완료 프로토콜은 캐시 무효화 과정의 내부 과정으로 완전 분산 형태로 효율적으로 구현되며, 일관성 체크의 대부분이 이동 클라이언트에서 수행된다. 또한, 분석 모델에 기반한 성능 비교를 통해, 본 논문에서 제안하는 OCC-UTS 프로토콜이 다른 경쟁 프로토콜보다 높은 트랜잭션 처리율을 얻으며, 데이터 항목을 자주 접근하면 할수록 지역 캐시를 사용하는 OCC-UTS 프로토콜이 더 효율적임을 보인다. 이동 클라이언트의 접속 단절에 대해서는 무효화 브로드캐스트 윈도우를 크게 하여 접속 단절에 적절히 대처할 수 있다.Abstract In a mobile computing environment, caching of frequently accessed data has been shown to be a useful technique for reducing contention on the narrow bandwidth of the wireless channels. However, the traditional client/server strategies for supporting transactional cache consistency that require extensive communications between a client and a server are not appropriate in a mobile client/server computing environment. In this paper, we propose a new protocol, called OCC-UTS (Optimisitic Concurrency Control with Update TimeStamp), to support transactional cache consistency in a mobile client/server computing environment by utilizing the broadcast-based solutions for the problem of invalidating caches. The consistency check on accessed data and the commitment protocol are implemented in a truly distributed fashion as an integral part of cache invalidation process, with most burden of consistency check being downloaded to mobile clients. Also, our experiments based on an analytical model substantiate the basic idea and study the performance characteristics. Experimental results show that OCC-UTS protocol without local cache outperforms other competitor protocol, and the more frequent a mobile client accesses data items the more efficient OCC-UTS protocol with local cache is. With respect to disconnection, the tolerance to disconnection is improved if the invalidation broadcast window size is extended.

• Journal of Korean Neurosurgical Society
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• v.30 no.3
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• pp.342-348
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• 2001

Objective : Dopamine transporter concentrations have been known to decrease in Parkinson's disease(PD). The aim of the present study was to evaluate the correlation between SPECT measurements of [I-123]N-(3-iodopropene-2-yl)-$2{\beta}$-carbomethoxy-$3{\beta}$-(4-chlorophenyl) tropane(IPT) as an imaging agent for measuring changes in transporter concentrations with PD. Patients and Methods : IPT labelled with $4.87{\pm}1.29mCi$($180.19{\pm}47.73MBq$) of [I-123] was intravenously injected into 23 patients(age : $58{\pm}12$) with PD and three normal controls(NC)(age : $37{\pm}7$) as bolus. Brain SPECT were then performed at 1 hour and 2 hours after injection on a double headed camera. The statistical parameters were the contrast ratio of left basal ganglia(BG) and right basal ganglia to occipital cortex(OCC) per milli curies of injected radiotracer at 1 hour and 2 hours. The correlations were evaluated between these parameters and Hoehn-Yahr classification of the patients. Results : The(BG - OCC)/OCC/mCi ratios at 1 hour and 2 hours for PD and NC were $0.14{\pm}0.07$ and $0.27{\pm}0.07$(1 hour) and $0.12{\pm}0.07$ and $0.34{\pm}0.04$(2 hour), respectively. The(BG - OCC)/OCC/mCi ratios of Parkinson's disease were decreased with higher grade of Hoehn-Yahr classification of the patients. The ratio between BG and OCC for PD were clearly separated from NC and may be useful outcome measures for clinical diagnosis. Conclusion : The findings suggest that IPT may be a very useful tracer for early diagnosis and treatment of PD and study of dopamine re-uptake site.

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2001.05a
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• pp.107-107
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• 2001

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.144-146
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• 2004

Stereo image analysis has been an important tool for reconstructing 3D terrain. By In its nature, occlusion is one of difficulties we cannot avoid in stereo matching. This paper presents a study on occlusion detection by employing LRC(Left-Right Check) and OCC(Occlusion Constraint). Experimental results show that these method can effectively detect occluded regions and those regions are usually occurred around object contours and scene discontinuity.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.5
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• pp.17-26
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• 2011

Drying behavior and physical properties of HwBKP, SwBKP, and OCC handsheets depending on kneading, refining and wet pressing were analyzed. The maximum drying shrinkage velocity was newly adopted to verify the effect of mechanical treatment of pulps by evaluating drying behavior according to varying the kneading, refining and wet pressing treatments. Those various treatments were changed to evaluate the relationship between the maximum drying shrinkage velocity and handsheets properties. When the drying shrinkage and the maximum drying velocity increased by refining and wet-pressing, handsheets strength was increased. The maximum drying shrinkage velocity showed higher correlation with physical properties of paper than WRV at different refining loads at SwBKP and mixed pulp. At high wet-web dryness, drying shrinkage, the maximum drying shrinkage velocity and strength properties of handsheet were increased. It meant that drying shrinkage behavior was highly affected by not only fibers' shrinkage but also fiber bonding. Kneading pre-treatment for KOCC and SwBKP effectively modified fiber properties and increasing paper strength and drying shrinkage. The effect of kneading pre-treatment was also confirmed by the maximum drying shrinkage velocity. Strength properties of mixed pulp handsheets were not increased by the kneading pre-treatment, although the maximum drying shrinkage velocity and WRV was increased. It meant that fibers network bonding of HwBKP was limited because of ves sels and ray cells' interference for bonding. Therefore in order to improve paper strengths containing HwBKP by mechanical treatments, interference of vessels and ray cells for fiber bondings should be carefully controlled.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.3_4
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• pp.138-148
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• 2003

Orthogonal Cross Cylinder mapping and segmentation based modeling methods have been implemented for constructing the image-based navigation system in this paper. The Orthogonal Cross Cylinder (OCC) is the object expressed by the intersection area that occurs when a cylinder is orthogonal with another. OCC mapping method eliminates the singularity effect caused in the environment maps and shows an almost even amount of area for the environment occupied by a single texel. A full-view image from a fixed point-of-view can be obtained with OCC mapping although it becomes difficult to express another image when the point-of-view has been changed. The OCC map is segmented according to the objects that form the environment and the depth value is set by the characteristics of the classified objects for the segmentation based modeling. This method can easily be implemented on an environment map and makes the environment modeling easier through extracting the depth value by the image segmentation. An environment navigation system with a full-view can be developed with these methods.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.2
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• pp.8-15
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• 2000

This study is a continuation of the previous experimental analysis and is mostly focused on handsheet strength properties. Four completely different fibers, which were Hw-BKP, SW-BKP, White ledger, and OCC, were selected to investigate the effect of mechanical pre-treatment by Hobart mixer on handsheet strehgth properties. After equal time mechanical pre-treatment, the fibers were refined with laboratory valley beater for 10, 20 and 30 minutes, and handsheets were prepared from the fibers for physical strength comparison. Handsheets from SW-BKP and OCC showed 5-30% increase of breaking length, burst index, tear index, and compression index while handsheets from HW-BKP and White ledger no increase except tear index. In Hobart mixer pre-treatment, HW-BKP and White ledger fibers were easily attached to the wall of the mixer bowl and mechanical action was not effectively applied. The fiber length of Hw-BKP and White ledger were 0.837 mm and 1.591 mm, respectively, while SW-BKP and OCC were 2.744 mm and 2.033 mm, respectively, in weight weighted length. The effective mechanical pre-treatment seems to be related to the fiber length. Tear indexes of the pre-treated furnish were much higher than no pre-treatment at the same breaking length level.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2000.04a
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• pp.70-70
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• 2000

This study is a continuation of the previous experimental analysis and is mostly focused on handsheet strength properties. Four completely different fibers, which were Hw-BKP, Sw-BKP, white ledger, and OCC, were selected to investigate the effect of mechanical pre-treatment by Hobart mixer on handsheet strength properties. After equal time mechanical pre-treatment, the fibers were refined with laboratory valley beater for 10, 20 and 30 minutes, and handsheets were prepared from the fibers for physical strength comparison. Handsheets from SW-BKP and OCC showed 5-30% increase of breaking length, burst index, tear index, and compression index while handsheets from HW-BKP and white ledger no Increase except tear index. In Hobart mixer pre-treatment, HW-BKP and white ledger fibers were easily attached to the wall of the mixer bowl and mechanical action was not effectively applied. The fiber length of Hw-BKP and white ledger were 0.837mm and 1.591 mm, respectively, while SW-BKP and OCC were 2.744 mn and 2.033 mm, respectively, in weight weighted length. The effective mechanical pre-treatment seems to be related to the fiber length. Tear indexes of the pre-treated furnish were much higher than no pre-treatment at the same breaking length level.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.3
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• pp.28-36
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• 2014

The kind and the mixing ratio of recovered papers would affect the quality of final recycled paper. In this study, effects of the mixing ratio of various domestic recycled papers (old news print (ONP), old corrugated container (OCC) and coated paper (CP)) on variations in physical properties of paper and its productivity were investigated. When the mixing ratio of CP grade increased, the freeness (CSF) of recycled pulp was increased while paper strength and white water turbidity was decreased. Paper strength was decreased as the percentage of OCC was higher than ONP. When ONP was mixed with OCC, no adverse effect was observed except the increased drainage resistance. It is expected that these results could be utilized as fundamental data to establish regulations for the recovered paper grades according to mixing ratios of different kinds of them.