• 천문학회보
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• 제42권2호
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• pp.56.2-56.2
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• 2017

We in the Korea Institute for Advanced Study are preparing the fifth Horizon Run in a series of large-scale cosmological simulations. For the first time we will include full hydrodynamics and astrophysical processes using a RAMSES code. I will discuss the impact of large-scale structures on smaller scale properties in cosmological hydrodynamic simulation to justify our choice of simulation boxsize, whose one side length is up to 1 Gpc.

• 대한환경공학회지
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• 제28권6호
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• pp.640-647
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• 2006

도금공장에서 발생하는 폐수에는 니켈 등 중금속이 고농도로 함유되어 있어 그 처리가 매우 어려운 편이며, 최근에는 공해물질의 발생을 사전에 예방하는 공정을 도입하거나, 발생된 폐수 및 폐기물을 적절히 처리하여 재활용하는 청정기술이 도입되는 추세이다. 본 연구에서는 니켈 도금 공정에서 발생되는 폐수를 대상으로 이온교환과 전기투석 공정을 이용하여 니켈의 회수가능성 및 효율을 평가하였다. 이온교환수지 5 종을 이용한 이온교환 실험결과 S 1467(gel-type 강산성 양이온 교환수지)의 교환용량이 가장 높았으며 재생실험결과 4 N HCl을 재생재로 사용한 경우에서 재생율 및 재생농도가 가장 높았다. 전류밀도, 전극액 농도, 농축액 및 전극액 유량을 변화시켜가며 운전한 전기투석 실험결과 최적의 운전조건은 전류밀도 $250A/m^2$, 전극액 농도 2 N $H_2SO_4$, 전극액 및 농축액 유량 30 mL/min였다. 이온교환수지 500 mL를 사용한 이온교환 scale-up 실험결과 S 1467 수지의 교환용량은 1.88 eq/L resin, 재생율은 93.7% 이었고 cell pair 수를 2개로 증가시킨 전기투석의 scale-up 실험결과, 농축 및 희석효율은 증가하였으나, 전류효율은 일정하였다.

• Journal of the Optical Society of Korea
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• 제14권4호
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• pp.388-394
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• 2010

In this paper the object recognition performance of a photon counting integral imaging system is quantitatively compared with that of a conventional gray scale imaging system. For 3D imaging of objects with a small number of photons, the elemental image set of a 3D scene is obtained using the integral imaging set up. We assume that the elemental image detection follows a Poisson distribution. Computational geometrical ray back propagation algorithm and parametric maximum likelihood estimator are applied to the photon counting elemental image set in order to reconstruct the original 3D scene. To evaluate the photon counting object recognition performance, the normalized correlation peaks between the reconstructed 3D scenes are calculated for the varied and fixed total number of photons in the reconstructed sectional image changing the total number of image channels in the integral imaging system. It is quantitatively illustrated that the recognition performance of the photon counting integral imaging system can be similar to that of a conventional gray scale imaging system as the number of image viewing channels in the photon counting integral imaging (PCII) system is increased up to the threshold point. Also, we present experiments to find the threshold point on the total number of image channels in the PCII system which can guarantee a comparable recognition performance with a gray scale imaging system. To the best of our knowledge, this is the first report on comparisons of object recognition performance with 3D photon counting & gray scale images.

• 한국의류학회지
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• 제32권7호
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• pp.1065-1074
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• 2008

The purpose of this paper was to present the proximity of clothing to self(PCS) which is a subjective measure developed by Sontag and Lee(2004). PCS is the scale to examine the relationship between self and clothing. Since PCS scale was prepared for American consumers, it is necessary to verify the validity as a measure to Korean consumers. Consumers' quality of life are functionally related to satisfaction with all of life's domain and subdomains. Clothing in life facilitates the creativity and expressiveness to the wearer, especially to adolescent. The concept of bottom-up spillover effect developed by Lee et al.(2002) was adopted as research model. Data were gathered by surveying university students using convenient sampling, 419 questionnaires were used in the statistical analysis. It was proved that PCS scale was effective measure to Korean consumers. And also PCS scale could be a proxy indicator in view of the fact that clothing was deeply related to consumers' quality of life.

• Clinics in Shoulder and Elbow
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• 제3권1호
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• pp.33-38
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• 2000

Objectives: The purpose of this study was to grading the severity of intra-articular lesions and evaluate the effects of arthroscopic surgery after manipulation of the resistant frozen shoulder. Materials and Methods : Forty-eight cases from 44 subjects, median age of 53, who underwent arthroscopic surgery after manipulation with minimum follow-up of 12 months were chosen. The UCLA shoulder rating scale was applied, and average scale was 18.2 points. Results: Twelve cases out of our series showed as rotator cuff tear which could produce secondary frozen shoulder. In postoperative follow up, 34 subjects complained of no pain or noctalgia, 5 showed mild degree of pain, 8 with mild degree of remained limited range of motion, and only 1 with no improvement. When viewed with UCLA shoulder rating scale, the most improved aspect was pain, and satisfaction of patient was following. And final average scale was 31.9 points. Conclusion: Our study revealed that arthroscopic surgery after manipulation showed favorably high final scale and patient's satisfaction. Therefore, we recommend this modality for treatment of resistant frozen shoulder in a point of view that the diagnosis and treatment can be done simultaneously.

• Child Health Nursing Research
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• 제13권4호
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• pp.436-443
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• 2007

Purpose: An exploratory study was done to examine the validity of the new Ballard scale with extended scoring system(eNBS) in estimating gestational age(AG) in full-term newborns. Method: The eNBS scoring system was extended to include all numbers of total score of NBS and GA to allow a 3-days variation in GA estimatio compared to the original scale which has a 2-week variation due to the application of a 5-score interval for the total NBS score and only even numbers for GA. GA by eNBS(GA-eNBS) was compared with GA by LMP(GA-LMP) and GA by standard NBS(GA-sNBS) in 133 full-term newborns. Difference between GA-LMP and GA-eNBS was analyzed for each GA. Results: Positive correlations were observed in GA-sNBS and GA-eNBS with GA-LMP. There was no difference between GA-LMP and GA-eNBS at 39GA and 40GA. At 37GA and 38GA, GA-eNBS overestimated GA-LMP up to 1 week, while underestimating up to 1 week at 41GA. Conclusions: The accuracy of eNBS was validated within 3 days of variation in GA estimation at 39-40GA. Overestimation by eNBS suggests the possible acceleration of fetal maturity in premature newborns, while underestimation, of the deceleration of fetal maturity in postterm newborns.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.46-46
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• 2001

• 시멘트
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• 통권24호
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• pp.23-28
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• 1968

• Environmental Engineering Research
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• 제11권1호
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• pp.14-27
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• 2006

The proper management of discarded electronic devices (often called electronic-waste) is an emerging issue for solid waste professionals throughout the world because of the large growth of the waste stream, and the content of toxic metals in them, most notably heavy metals such as lead. Notebook computers are becoming one of the major components of discarded computer devices and will continue to increase in the waste stream in the future. While the computers hold great promise for recycling, a substantial amount of this waste is often disposed in municipal solid waste (MSW) landfills. The toxicity characteristic leaching procedure (TCLP) is commonly used to simulate worse case leaching conditions where a potentially hazardous waste is assumed to be disposed along with municipal solid waste in a landfill with actively decomposing materials overlying an aquifer. The objective of this study was to examine leaching potential of lead from discarded notebook computers using the scale-up TCLP, other standard leaching tests such as California waste extraction test (Cal WET), and the synthetic precipitation leaching procedure (SPLP) and actual landfill leachates as leaching solution. The scale-up TCLP is a modified TCLP (where the device was disassembled and leached in or near entirety) to meet the intent of the TCLP. The results showed that the scale-up TCLP resulted in relatively high lead found in the leachate with an average of 23.3 mg/L. The average level was less than those by the standard TCLP and WET (37.0 mg/L and 86.0 mg/L, respectively), but much greater than those by the SPLP and the extractions with the landfill leachates (0.55 mg/L and 1.47 mg/L, respectively). The pH of the leaching solution and the ability of the organic acids in the TCLP and WET to complex with the lead were identified as major factors that controlled the amount of lead leached from notebook computers. Based on the results obtained by a number of leaching tests in this study, notebook computers may present a potential leaching risk to the environment and human health upon land disposal. However, further investigation is still needed to assess the true risk posed by the land disposal of discarded notebook computers.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2536-2539
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• 2008

A study has been made on how to occur inertial oscillations in a rotating flow. The flow is considered to be induced by differentially-rotating top and bottom disks with infinite radius. The top and bottom disks are assumed to be set in motion over a finite initial start-up time duration from initial solid body rotation ($\Omega$) to each finial state, i.e., the top disk is rotating at the angular velocity (${\Omega}+{\Delta}{\Omega}$) and the bottom disk (${\Omega}-{\Delta}{\Omega}$). The system Reynolds number, which is a reciprocal of conventional Ekman number in rotating flows, is very high so that a boundary layer flow near disks is pronounced. From a strict theoretical analysis, it is clearly found the fact that inertial oscillation in a rotating flow is caused by excessive input of torque during start-up phase. Above finding comes from the following physics of theoretical result: in the case of abrupt start-up within very shorter time-duration than spin-up time scale, the inertial oscillation is magnified but it could be completely depressed in the case of mildly accelerated start-up, i.e., start-up process being established over diffusion time scale.