• Title/Summary/Keyword: index of difficulty

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Synthetic Infra-Red Image Dataset Generation by CycleGAN based on SSIM Loss Function (SSIM 목적 함수와 CycleGAN을 이용한 적외선 이미지 데이터셋 생성 기법 연구)

  • Lee, Sky;Leeghim, Henzeh
    • Journal of the Korea Institute of Military Science and Technology
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    • v.25 no.5
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    • pp.476-486
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    • 2022
  • Synthetic dynamic infrared image generation from the given virtual environment is being the primary goal to simulate the output of the infra-red(IR) camera installed on a vehicle to evaluate the control algorithm for various search & reconnaissance missions. Due to the difficulty to obtain actual IR data in complex environments, Artificial intelligence(AI) has been used recently in the field of image data generation. In this paper, CycleGAN technique is applied to obtain a more realistic synthetic IR image. We added the Structural Similarity Index Measure(SSIM) loss function to the L1 loss function to generate a more realistic synthetic IR image when the CycleGAN image is generated. From the simulation, it is applicable to the guided-missile flight simulation tests by using the synthetic infrared image generated by the proposed technique.

Item Analysis for Selecting Science Gifted Elementary School Student (초등과학영재교육원의 선발 문항 분석)

  • Lim, Chun-Woo
    • Journal of Science Education
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    • v.34 no.1
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    • pp.155-163
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    • 2010
  • The purpose of this study was to analyze the items that were used in entrance examination for science gifted education center for elementary school students by using content analysis and classical item analysis. In content analysis, objective type items exhibited matter and interpreting data were dominant. And essay type items consisted of creativity items, evaluated creative problem solving ability. Item difficulty and discrimination index, on the whole, were appropriate. Comparing with objective type, essay type has higher discrimination index. In correlation analysis between total score and score of each type of items, total score has the highest correlation with matter items, interpreting data and creativity.

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Self-esteem item goodness-of-fit in sports talented children (스포츠영재들의 자아존중감 문항적합도)

  • Kim, Eung-Joon;Kim, Jong-Kyu;Lee, Nam-Ju;Lee, Mi-Sook
    • Journal of the Korean Data and Information Science Society
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    • v.22 no.3
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    • pp.487-494
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    • 2011
  • The purpose of this study was to investigate self-esteem item goodness-of-fit in sports talented children with socio-psychological aspect, which may be a basis of developing global sports leaders. Fifty children who were selected by 2010 sports talent identification program at Korea National Sport University participated in this study. All participants were asked to answer the questionnaire using Rogenberg (1965) self-esteem scale. Total 8 questions were used with 4 point Likert scale and high point stands for higher self-esteem status. Reliability of Cronbach's ${\alpha}$ was.785 in this study. Frequency analysis, descriptive statistics, and reliability analysis were conducted with SPSS 18.0. WINSTEPS 3.70 (Linacre, 2010) was used for calculating item goodness-of-fit and subject reliability, scale propriety, item goodness-of-fit and item level of difficulty, and level of difficulty were calculated. Statistical analysis showed results as follows. First, it was reported to be suitable for subject reliability in self-esteem as 1.01~1.03 and item reliability as 1.01~1.01. Second, 4 scale was suitable for scale propriety resulting from stage index judgment. Third, 2,7,8 and 3 question showed problems in item goodness-of-fit and item level of difficulty. Finally, scale propriety was reported to be inappropriate for considering sports talented children's ability distribution and scale level of difficulty.

A Study on Estimation Technique of Manoeuvring Difficulty Using the Ship Manoeuvre Simulator for Berthing/Deberthing (선박 접이안 조종 시뮬레이터를 이용한 조종위험도 평가 기법에 관한 연구)

  • Yang Seung-Yeul;Sohn Kyoung-Ho;Lee Hee-Yong;Ha Mun-Keun;Kim Hyun-Soo;Lee JIn-Ho;Im Nam-Kyun
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2004.11a
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    • pp.81-87
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    • 2004
  • It includes the considerable concentration and dangerousness as the peculiar work of a pilot and dock-master to berthing/deberthing the big object as for the ship within the port or the ship yard. A tug utilization is getting increased in this berthing/deberthing work and the own ship is affected a lot by external force due to moving with low advance speed. In this study, we constructed the 2 dimension virtual system which can conduct the berthing/deberthing manoeuvring work by using mainly tugs in a external force, particularly strong wind. Also, propose objective standard that could estimate the degree of manoeuvring difficulty, and conducted simulation experiment for this. we analyzed correlations between the subjective estimation which is described numerically the decreased dangerousness and the objective index which is related to the main parameter regarding manoeuvring by using this simulator from the result of conducting simulation experiment. And then we discussed the estimation technique of manoeuvring difficulty.

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Observation Test of Field Surface Reflectance Using Vertical Rotating Goniometer on Tarp Surface and Grass (수직 축 회전형 측각기 제작 및 야외 지표면 반사도 관측 시험: 타프와 잔디에서)

  • Moon, Hyun-Dong;Jo, Euni;Kim, Hyunki;Cho, Yuna;Kim, Bo-Kyeong;Ahn, Ho-Yong;Ryu, Jae-Hyun;Cho, Jaeil
    • Korean Journal of Remote Sensing
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    • v.38 no.6_1
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    • pp.1207-1217
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    • 2022
  • Vegetation indices using the reflectance of selected wavelength, associating with the monitoring purpose such as identifying the progress of crop growth, on the vegetation canopy surface is widely used in the digital agriculture technology. However, the surface reflectance anisotropy can distort the true value of vegetation index related to the condition of surface, even though the surface property be unchanged. That causes difficulty to observe accurately crop growth on the monitoring system. In this study, a simple type goniometer was designed to measure the reflectance from the anisotropic surface according to various zeniths and azimuths of sun and viewing sensor in the field. On the tarp like as Lambertian surface, the reflectance of Blue, Green, Red, Near-Infrared band was similar to the tarps' reflectance properties. However, the reflectance was slightly overestimated in the cloudy day. The relative difference values of vegetation indices on grass were overestimated for the forward viewing and underestimated for the backward viewing. In addition, enhanced vegetation index (EVI) showed less sensitive according to the positions of sun and sensor viewing. Field observation with a goniometer will be helpful to understand the anisotropy characteristics on the vegetation surface.

Development of the Business Survey Index Evaluation Model for Overseas Construction Companies (해외건설 진출기업을 위한 기업경기실사지수 평가모델 개발)

  • Park, Hwan-Pyo;Ko, Hyun-A
    • Journal of the Korea Institute of Building Construction
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    • v.22 no.3
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    • pp.305-316
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    • 2022
  • Domestic construction companies have difficulty in establishing strategies when entering overseas markets because they do not have an overseas construction economic sentiment index to refer to for data on overseas construction prospects. Considering that the fluctuation of overseas construction orders over the past decade has been substantial and large companies and SMEs are actively advancing overseas, this study developed an evaluation model for an overseas construction business sentiment index to grasp the economic experience of overseas construction companies. In 2021 Korean companies earned 30.6 billion in overseas construction contracts, 87% the level of the previous year, despite difficulties such as COVID-19 and low oil prices, thanks to efforts by construction companies to strengthen their strategies for entry, such as regional diversification, and government support for winning orders. Since the overseas construction industry fluctuates greatly due to changes in the international environment, it is necessary to investigate and analyze the economic sentiment index of overseas construction companies. In particular, despite the increase in overseas expansion of small and medium-sized construction companies and engineering companies, the provision of information on the overseas construction market sentiment index is insufficient, limiting the establishment of strategies for overseas construction expansion. Therefore, this study intends to develop an overseas construction market sentiment index model that can understand the economic sentiment of overseas construction companies, provide a forecast for overseas construction, and use it to establish overseas construction strategies and policies.

Quality of Life after Curative Surgery in Patients with Gastric Cancer: Comparison between a Subtotal Gastrectomy and a Total Gastrectomy (위암 환자에 있어서 위의 절제범위에 따른 수술 후 삶의 질 비교)

  • -Yu, Wansikik;Lee, Chang-Hwan;Chung, Ho-Young
    • Journal of Gastric Cancer
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    • v.1 no.1
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    • pp.44-49
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    • 2001
  • Purpose: Quality of life (QOL) assessment should be applied in surgical settings to compare treatment options. We compared QOL after a subtotal versus a total gastrectomy for gastric cancer to identify which resection would produce a better QOL for the patient. Patients and Methods: We studied 362 patients with no evidence of recurrent disease after curative surgery for gastric cancer. The QOL was measured by assessing patient health perceptions according to the Spitzer index and Troidl score and by treatment-specific symptoms according to Korenaga and others with some modifications. High scores reflect a better QOL. Results: The mean score of the Spitzer index was $8.87\pm1.36$ after a subtotal gastrectomy and $8.80\pm1.23$ after a total gastrectomy. More than $80\%$ of the patients in both groups maintained good quality of life when measured by the Spitzer index. The mean Troidl score was $10.41\pm2.12$ after a subtotal gastrectomy and $9.79\pm2.16$ after a total gastrectomy (p=0.033). Swallowing difficulty was more frequent after a total gastrectomy (p=0.002). There was a statistically significant difference in the meal size (p=0.044). Other variables of the Troidl score revealed no statistically significant differences. Dizziness was significantly more frequent after a total gastrectomy than after a subtotal gastrec tomy (p=0.009). Conclusion: We conclude that in terms of postoperative quality of life, a subtotal gastrectomy has advantages over a total gastrectomy. In those cases where an adequate proximal safety margin can be achieved by a subtotal gastrectomy, that procedure is preferable to a total gastrectomy.

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A Study on Particular Abnormal Gait Using Accelerometer and Gyro Sensor (가속도센서와 각속도센서를 이용한 특정 비정상보행에 관한 연구)

  • Heo, Geun-Sub;Yang, Seung-Han;Lee, Sang-Ryong;Lee, Jong-Gyu;Lee, Choon-Young
    • Journal of the Korean Society for Precision Engineering
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    • v.29 no.11
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    • pp.1199-1206
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    • 2012
  • Recently, technologies to help the elderly or disabled people who have difficulty in walking are being developed. In order to develop these technologies, it is necessary to construct a system that gathers the gait data of people and analysis of these data is also important. In this research, we constructed the development of sensor system which consists of pressure sensor, three-axis accelerometer and two-axis gyro sensor. We used k-means clustering algorithm to classify the data for characterization, and then calculated the symmetry index with histogram which was produced from each cluster. We collected gait data from sensors attached on two subjects. The experiment was conducted for two kinds of gait status. One is walking with normal gait; the other is walking with abnormal gait (abnormal gait means that the subject walks by dragging the right leg intentionally). With the result from the analysis of acceleration component, we were able to confirm that the analysis technique of this data could be used to determine gait symmetry. In addition, by adding gyro components in the analysis, we could find that the symmetry index was appropriate to express symmetry better.

Effects of sleep-inducing juice on sleep quality and heart rate variability in adults with disturbed sleep

  • Kim, Choun-sub;Kim, Maengkyu;Kim, Min-ju;Jung, Hyeyoung
    • Nutrition Research and Practice
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    • v.14 no.6
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    • pp.606-620
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    • 2020
  • BACKGROUND/OBJECTIVES: Although some juices affect subjective sleep quality, there is a lack of information on the effect of a specific juice on objective sleep quality and heart rate variability (HRV) during sleep; thus the present study investigated whether a blended juice made from natural extracts influenced sleep quality and HRV during sleep in adults with disturbed sleep. SUBJECTS/METHODS: A randomized, crossover study was conducted on twenty-five adults (15/10, female/male) complaining of difficulty initiating or maintaining nighttime sleep (Pittsburgh sleep quality index [PSQI] ≥ 5). During feeding sessions (FS), subjects received sleep-inducing juice made of natural ingredients (250 mL/trial) twice a day for 8 weeks or non-FS (N-FS) for 8 weeks while maintaining normal activities. Sleep quality and parameters were recorded via wearable actigraph for 7 consecutive days, and PSQI scores were assessed before and after the intervention. HRV was also monitored at rest and during sleep. RESULTS: After receiving the sleep-inducing juice intervention (FS), PSQI scores were significantly decreased (P < 0.001) and correlated with a significant decline in fatigue severity scale and visual analogue scale levels (P < 0.05; both). HRV indices of vagal activity were significantly improved during FS (P < 0.05), and no significant differences in N-FS were observed. Sleep efficiency and total sleep time increased significantly (P < 0.05) and sleep latency, total counts, sleep fragmentation index, and movement index, decreased significantly (P < 0.05, all 4) during FS, with no significant differences-observed during N-FS. CONCLUSIONS: This study results demonstrated that an 8-week course of sleep-inducing juice has led to improve sleep quality, suggesting an enhanced cardiac vagal tone during sleep. Thus, it could be a well-tolerated option for adults with disturbed sleep.

A New Statistical Index for Detecting Cheaters on Multiple Choice Tests (다중선택 시험에서 부정행위자 발견을 위한 새로운 통계적 측도)

  • Han, Eun Su;Lim, Johan;Lee, Kyeong Eun
    • The Korean Journal of Applied Statistics
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    • v.26 no.1
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    • pp.81-92
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    • 2013
  • It is important to construct a firm basis for accusing potential violators of academic integrity in order to avoid spurious accusations and false convictions. Educational researchers have developed many statistical methods that can either uncover or confirm cases of cheating on tests. However, most of them rely on simple correlation-based measures, and often fail to account for patterns in responses or answers. In this paper, we propose a new statistical index denoted by a Standardized Signed Entropy Similarity Score to resolve this difficulty. In addition, we apply the proposed method to analyze a real data set and compare the results to other existing methods.