• Korean Journal of Fisheries and Aquatic Sciences
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• v.1 no.2
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• pp.105-113
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• 1968

The following experiments were carried out at rock method oyster field at Uduri, Dolsan-myon, Yeocheon-gun, Jeon-nam, Korea, in 1966. In this experiment, the settling rate of oyster at each exposure level and their growth rate were checked. 1. The settling rate of oyster spats was highest at 4 hour exposure level in the day-time during spring tide, and the growth rate became greater the lower stratum until 3 hours and 30 minutes exposure level. 2. Rocks applied at the place higher than 5 to 6 hour exposure level which amount 26 percents of applied rocks, were not utilized properly because the settling rate of spats and their growth rate were very bad. 3. For the future application of rocks for oyster culture, effort should be paid to instruct the oyster farmers to apply all rocks at proper exposure Ie el with bottom leveling and the rocks should be spaced properly for better barvest.

• Journal of the Mineralogical Society of Korea
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• v.22 no.4
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• pp.289-295
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• 2009

The characteristics of phosphate desorption on kaolinite was studied by batch adsorptiondesorption experiments. Desorption procedure was carried out through sequential extraction method at pH 4. The phosphorous contents were measured using UV-VIS-IR spectrophotometer with 820 nm wavelength. The adsorption-desorption reaction of P on kaolinite was irreversible, and most of adsorbed P on kaolinite were not easily dissolved to aqueous solution, but may might be fixed on kaolinite surface. The desorption isotherms were well fitted with the Freundlich and Temkin equations in the case of short reaction and long reaction time, respectively. The desorption reaction was divided into the early fast reaction and the later slow reaction. The percentage of desorption generally decreased with increasing adsorbed P concentration and increasing desorption reaction time.

• Journal of Radiation Protection and Research
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• v.23 no.1
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• pp.33-47
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• 1998

Using a combination of an X-ray generator Installed in radiation calibration laboratory of Korea Atomic Energy Research Institute (KAERI) and a series of 8 radiators and filters described in ISO-4037, monoenergetic fluorescent X-rays from 8.6 keV to 75 keV were produced. This fluorescent X-rays generated by primary X-rays from radiator were discriminated $K_{\beta}$ lines with the aid of filter material and the only $K_{\alpha}$ X-rays were analyzed with the high purity Ge detector and portable MCA. The air kerma rates were measured with the 35 co ionization chamber and compared with the calculational results, and the beam uniformity and the scattered effects of radiation fields were also measured. The beam purities were more than 90 % for the energy range of 8.6 keV to 75 keV and the air kerma rates were from 1.91 mGy/h (radiator : Au, filter : W) to 54.2 mGy (radiator : Mo, filter : Zr) at 43 cm from center of the radiator. The effective area of beam at the measurement point of air kerma rates was 12 cm ${\times}$ 12 cm and the influence of scattered radiation was less than 3 %. The fluorescent X-rays established in this study could be used for the determination of energy response of the radiation measurement devices and the personal dosemeters in low photon energy regions.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2002.05a
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• pp.37-42
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• 2002

현행 출입국 관리는 사용자가 여권을 제시하면, 여권을 육안으로 검색하고 수작업으로 정보를 입력하여 여권의 데이터 베이스와 대조하였다. 이러한 종래의 출입국 관리 시스템은 출입국 심사 시간이 길어 출입국자에 불편을 제공하고 출입국 부적격자에 대한 정확한 검색이 이루어지지 않아 체계적으로 관리하기가 어려웠다. 이리한 종래의 문제점을 개선하기 위해 영상 처리와 문자 인식을 이용한 여권 인증 시스템을 제안한다. 된 논문에서는 여권 영상에 대해 소벨 연산자와 스미어링 기법 그리고 윤곽선 추적 알고리즘을 이용하여 사진영역, 코드 영역 및 개별 코드 문자를 추출하고 개별 코드 문자 인식은 기존의 퍼지 ART를 개선하여 적용한다. 다양한 국내 여권 영상에 대해 제안된 여권 인식 방법을 실험한 결과, 제안된 방법이 여권 인식에 우수한 성능을 보였고 개선된 퍼지 ART 알고리즘이 기존의 퍼지 ART 알고리즘보다 클러스터 수가 적게 생성되고 인식률도 향상된 것을 확인하였다

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.239-241
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• 2015

본 논문에서는 클러스터 개수를 동적으로 생성하는 개선된 FCM을 적용하여 초음파 영상에서 충수염을 추출하는 방법을 제안한다. 초음파 영상에서 ROI 영역을 추출한 후, Max-Min 기반 이진화 기법을 적용한다. 이진화된 영상에서 근막 영역의 크기가 ROI 영역의 1/3이상을 차지한다는 정보를 이용하여 Labelling 기법을 적용하여 근막 영역을 추출한다. 근막의 최하단 좌표를 이용하여 근막의 하단 영역을 추출한 후, 근막의 하단 영역에서 객체들의 선명도를 높이기 위해 Blurring 기법과 Sharpening 기법을 적용한다. 충수염의 후보 영역을 추출하기 위해 FCM 알고리즘을 개선하여 양자화를 수행한다. 개선된 FCM 알고리즘으로 양자화를 수행하여 충수염의 후보 영역을 추출한다. 추출된 충수염의 후보 영역에서 8방향 윤곽선 추적 기법을 적용하여 객체들을 추출한다. 추출된 객체들 중에서 낮은 명암도를 가지고 초음파 전체 영상 크기의 1/3이하 되는 객체를 충수염으로 추출한다. 초음파 영상을 대상으로 제안된 방법을 적용하여 실험한 결과, 기존의 방법보다 충수염 영역의 추출률이 개선된 것을 확인하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.11a
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• pp.129-132
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• 2006

본 논문에서는 카메라 영상으로부터 사각형 형태의 마커를 검출하고 인식하는 방법을 제안한다. 본 논문에서는 사각형 형태의 마커 검출을 위하여 입력 영상을 이진 영상으로 변환하고 객체들의 윤곽선을 추출한 다음에 윤곽선을 선분으로 근사화 한다. 근사화된 선분으로부터 기하학적 특징을 이용하여 사각형을 찾는다. 마커의 사각형 영역을 찾은 다음에는 워핑 기법을 이용하여 사각형 마커 영상으로부터 특징 벡터를 추출하고 표준 마커에 대한 특징 벡터와의 최소 거래법에 의해 마커의 종류를 인식한다. 인식 실험 결과 마커의 종류가 50개일 때에 최대 98%의 인식률을 얻을 수 있었다.

• Proceedings of the Korea Contents Association Conference
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• 2005.11a
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• pp.633-638
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• 2005

The extraction of a face is a very important part for human interface, biometrics and security. In this paper, we applies DCM(Dilation of Color and Motion) filter and Active Contour Models to extract facial outline. First, DCM filter is made by applying morphology dilation to the combination of facial color image and differential image applied by dilation previously. This filter is used to remove complex background and to detect facial outline. Because Active Contour Models receive a large effect according to initial curves, we calculate rotational degree using geometric ratio of face, eyes and mouth. We use edgeness and intensity as an image energy, in order to extract outline in the area of weak edge. We acquire various head-pose images with both eyes from five persons in inner space with complex background. As an experimental result with total 125 images gathered by 25 per person, it shows that average extraction rate of facial outline is 98.1% and average processing time is 0.2sec.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.2
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• pp.219-224
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• 2011

Recently increasing importance of information security, personal security is researched. Among them, biometrics research is very good at recognition and security particularly in terms of iris recognition. Recent hospital physicians and employees for access control is emphasized. But most of them, easy-employee card access control systems are used. It has difficulties of iris recognition on the issue of accurate iris recognition algorithm to eliminate noise and inaccuracy of pretreatment methods for recognition from existing research. Therefore, this paper complements existing encryption methods to the disadvantages of biometric iris recognition using high-access records in the hospital management system is applied. In addition to conventional pretreatment process to increase recognition eyebrows when mask line component added to the extraction mask, the correct preparation method, and accordingly proposed to improve the recognition of records management systems offer access to the hospital.

• The Korean Journal of Applied Statistics
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• v.23 no.1
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• pp.49-61
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• 2010

The time series dependencies of Financial volatility are frequently measured by the autocorrelation function of power-transformed absolute returns. It is known as the Taylor property that the autocorrelations of the absolute returns are larger than those of the squared returns. Hass (2009) developed a simple method for detecting the Taylor property in absolute-value-GAROH(1,1) (AVGAROH(1,1)) model. In this article, we fitted AVGAROH(1,1) model for various Korean financial time series and observed the Taylor property.

• Journal of Astronomy and Space Sciences
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• v.3 no.2
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• pp.93-102
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• 1986

For a geostationary satellite east-west station keeping maneuvers must control both the mean longitude and the orbit eccentricity simultaneously. The effect on the orbit eccentricity of maneuvers may be reprensented by a phse plane of $e_{c}$ verse $e_{s}$, since these eccentricity elements give the projection of the orbit center onto the equatorial plane in units of the semimajor axis. The evolution of the mean longitude and the orbit eccentricity are obtained.