• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅳ
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• pp.1807-1810
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• 2003

Steganography based on Just Noticeable Difference(JND) has been used for natural images. However, it has been recognized to have defects for the non-natural images such as scanned text images, cartoons, etc. In this paper, an alternative method is proposed to improve this problem. A new scheme is designed specially for the non-natural images. Instead of JND, Noise Visibility Function(NVF) is used. NVF value and edge strength value of each pixel ate combined to decide the embedding data capacity and the visibility of data embedded images have been improved specially for the non-natural images.

• 한국산업정보학회논문지
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• 제15권1호
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• pp.59-72
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• 2010

최근 급변하는 경쟁 환경에서 기업과 기업 간의 경쟁 차원을 넘어서 공급사슬과 공급사슬과의 경쟁으로 발전하고 있다. 본 연구에서는 공급사슬 통합요인인 기업내부 기능 간 통합, 공급자 통합, 고객 통합이 기업내부 가시성과 기업외부 가시성 및 기업의 비재무적 성과와 재무적 성과에 미치는 영향을 검증하였다. 실증연구를 위해서 국내 SCM을 실행하고 있는 공급업체 제조업체, 유통업체들을 대상으로 설문조사를 실시하여 총 81부의 설문자료를 최종 분석하였다. 공변량 구조모형분석을 실시한 결과는 다음과 같다. 첫째, 공급자 통합은 기업내부 가시성과 기업외부 가시성에 유의한 영향을 미치는 것으로 나타났으나, 기업내부 기능 간 통합은 기업내부 가시성에만, 고객 통합은 기업외부 가시성에만 유의한 영향을 미치는 것으로 나타났다. 둘째, 기업내부 가시성과 기업외부 가시성은 기업의 비재무적 성과에는 유의한 영향을 미치는 것으로 나타났으나, 재무적 성과에는 직접적으로 유의한 영향을 미치지 않는 것으로 나타났다. 셋째, 기업의 비재무적 성과는 재무적 성과에 유의한 영향을 미치는 것으로 나타났다.

• Journal of Gastric Cancer
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• 제24권3호
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• pp.280-290
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• 2024

Purpose: Despite annual endoscopy, patients with metachronous remnant gastric cancer (MRGC) following proximal gastrectomy (PG) are at times ineligible for endoscopic resection (ER). This study aimed to clarify the clinical risk factors for ER inapplicability. Materials and Methods: We reviewed the records of 203 patients who underwent PG for cT1 gastric cancer between 2006 and 2015. The remnant stomach was categorized as a pseudofornix, corpus, or antrum. Results: Thirty-two MRGCs were identified in the 29 patients. Twenty MRGCs were classified as ER (ER group, 62.5%), whereas 12 were not (non-ER group, 37.5%). MRGCs were located in the pseudo-fornix in 1, corpus in 5, and antrum in 14 in the ER group, and in the pseudofornix in 6, corpus in 4, and antrum in 2 in the non-ER group (P=0.019). Multivariate analysis revealed that the pseudo-fornix was an independent risk factor for non-ER (P=0.014). In the non-ER group, MRGCs at the pseudo-fornix (n=6) had more frequent undifferentiated-type histology (4/6 vs. 0/6), deeper (≥pT1b2; 6/6 vs. 2/6) and nodal metastasis (3/6 vs. 0/6) than non-pseudo-fornix lesions (n=6). We examined the visibility of the region developing MRGC on an annual follow-up endoscopy one year before MRGC detection. In seven lesions at the pseudofornix, visibility was only secured in two (28.6%) because of food residues. Of the 25 lesions in the non-pseudo-fornix, visibility was secured in 21 lesions (84%; P=0.010). Conclusions: Endoscopic visibility increases the chances of ER applicability. Special preparation is required to ensure the complete clearance of food residues in the pseudo-fornix.

• 한국의류산업학회지
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• 제24권4호
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• pp.471-478
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• 2022

In roadside workplaces, more attention should be paid to the safety of workers. The roadside workers underestimate the effect of the brightness of their clothes and judge that drivers will recognize them easily, and the drivers misjudge that the roadside workers are far away and that the vehicle can be stopped in sufficient time. Therefore, customized safety education reflecting this and wearing work clothes with certified visibility functions are required. In Korea, it is not compulsory for roadside workers and vehicle guide attendants to wear work clothes with a visibility function. In this study, the distance ahead perceived by drivers was measured using manikins wearing certified and non-certified reflective safety vests. The perception distance of the non-certified reflective safety vest was 1.4 times longer than that of the certified reflective safety vest, thus confirming the importance of wearing a certified reflective safety vest. To prevent roadside workers from suffering traffic accidents, we propose the enactment of a law that makes it mandatory for them to wear high-visibility safety clothing. Specifically, Article 32 of the Enforcement Regulation of the Road Traffic Act should include high-visibility safety clothing in life protection equipment, and additionally, to prevent secondary accidents, we propose the enactment of a law requiring the installation and wearing of certified reflective safety vests in vehicles.

• Korean Journal of Radiology
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• 제21권11호
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• pp.1210-1219
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• 2020

Objective: To compare the utility and diagnostic performance of automated breast ultrasound system (ABUS) with that of handheld ultrasound (HHUS) in evaluating pure non-mass enhancement (NME) lesions on breast magnetic resonance imaging (MRI). Materials and Methods: One hundred twenty-six consecutive MRI-visible pure NME lesions of 122 patients with breast cancer were assessed from April 2016 to March 2017. Two radiologists reviewed the preoperative breast MRI, ABUS, and HHUS images along with mammography (MG) findings. The NME correlation rate and diagnostic performance of ABUS were compared with that of HHUS, and the imaging features associated with ABUS visibility were analyzed. Results: Among 126 pure NME lesions, 100 (79.4%) were malignant and 26 (20.6%) were benign. The overall correlation rate was 87.3% (110/126) in ABUS and 92.9% (117/126) in HHUS. The sensitivity and specificity were 87% and 50% for ABUS and 92% and 42.3% for HHUS, respectively, with no significant differences (p = 0.180 and 0.727, respectively). Malignant NME was more frequently visualized than benign NME lesions on ABUS (93% vs. 65.4%, p = 0.001). Significant factors associated with the visibility of ABUS were the size of NME lesions on MRI (p < 0.001), their distribution pattern (p < 0.001), and microcalcifications on MG (p = 0.027). Conclusion: ABUS evaluation of pure NME lesions on MRI in patients with breast cancer is a useful technique with high visibility, especially in malignant lesions. The diagnostic performance of ABUS was comparable with that of conventional HHUS in evaluating NME lesions.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.1315-1316
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• 2015

본 논문에서는 원자력발전소 중대 사고를 모사한 비가시 환경에서 적외선 열화상카메라의 관측성능 (가시도)을 정량적으로 평가하고자 하였다. 이를 위해 세계기상기구의 가시도 정의를 이용하여 가시도를 측정하였으며, 측정된 가시도 조건에서 적외선 열화상카메라의 관측성능을 평가하였다.

• 한국콘텐츠학회논문지
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• 제13권6호
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• pp.390-400
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• 2013

본 논문에서는 실시간 기업(Real Time Enterprise: RTE) 특성이 공급사슬성과에 미치는 영향에 대해 연구한다. 현재의 공급사슬 성과측정은 재무적, 비재무적, BSC, SCOR 측면에서 진행되고 있지만, 충분하지 못한 실정이다. 본 연구에서는 제품품질, 인도속도, 프로세스 유연성, 가격리더십으로 측정되는 조합적 경쟁역량의 측면에서 SCM 성과를 측정하고자 하였다. 본 연구는 가시성, 민첩성, 조합적 경쟁역량의 변수들을 사용하여 다음과 같은 사실을 밝혔다: (i) 가시성은 민첩성에 유의한 영향을 미친다. (ii), 가시성은 조합적 경쟁역량에 유의한 영향을 미친다. (iii) 민첩성 또한 조합적 경쟁역량에 유의한 영향을 미친다.

• 한국항해항만학회지
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• 제34권4호
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• pp.293-298
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• 2010

The residential comfort and safety on ship are more focused than ever, in accordance with the increase of the crews' onboard time and interest in cruiser sailing. To grasp the safety characteristics on ships against various scenarios of evacuations, this study performed experiments and simulations for the evacuation times on a training ship. Through the experiments, the average walking speed is 3.0m/s on 100% visibility, and 1.2m/s on 8% visibility, but the speeds go down 1.3m/s and 0.7m/s, respectively, when obstacles are happened without any previous notification. From the simulation, it is clearly reconfirmed that the worse visibility and many people make evacuation time comparatively longer. And unlike the common expectation of the effect of emergency announcement, the difference of evacuation times between cases of announcement and non-announcement is negligible on this study. From the survey after experiments, it is known that experiment participants feel unsafe and fear when the evacuation routes are longer in bad visible condition, even if they know the perfect evacuation route. And the survey results also show that the evacuees give more careful consideration to make a evacuation route decision under bad visibility.

• 제어로봇시스템학회논문지
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• 제22권5호
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• pp.367-373
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• 2016

In this paper, range measurement performance of LRF (Laser Range Finder) module and image contrast of color CCD camera are evaluated under the aerosol (high temperature steam) environments, which are simulated severe accident conditions of the LWR (Light-Water-Reactor) nuclear power plant. Data of LRF and color CCD camera are key informations, which are needed in the implementation of SLAM (Simultaneous Localization and Mapping) function for emergency response robot system to cope with urgently accidents of the nuclear power plant.

• 한국도로학회논문집
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• 제18권6호
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• pp.87-96
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• 2016

OBJECTIVES : A fog generated field test was conducted to analyze the relationship between different sizes of variable speed limit signs and the legibility distance under various fog density conditions. By using this study, appropriate sizes of signs can be selected depending on the density of fog. METHODS : An actual tunnel was selected as the area for this test, as other places cannot maintain the fog condition because of rapid air current. A total 121 subjects were recruited for this test, which took place over the course of four days. The test on the first day was conducted under normal weather conditions for comparison. Visibility-distance detecting sensor was used to measure the visibility distance due to the fog density time, simultaneously with the evaluation of legibility distance by subjects. RESULTS : The test results show the relationship between the different sizes of signs and the legibility distance corresponding to the visibility distance due to both non-fog and fog generated conditions. According to the technical test results, appreciable amount of reduction in legibility distance due to fog was resulted in all sizes of signs. Moreover, the legibility distance is reduced proportionately with the decrease in the visibility distance due to fog. CONCLUSIONS : The results of this study can be used to select appropriate sizes of valuable speed signs under fog conditions. Hence, drivers can expect to have more room to respond to adverse weather conditions, thereby reducing the risk of accidents.