• Journal of the Microelectronics and Packaging Society
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• v.15 no.1
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• pp.65-69
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• 2008

This work shows that the grinding-induced scratches formed on the back surface of silicon chips can highly influence the flexural strength of the chips. Meanwhile, in a case that excellent adhesion between the back surface and the plastic package body maintains, the flexural strength of plastic-encapsulated packages is not so sensitive to the geometry of the scratch marks. This article explains why such different flexural fracture behavior between bare chips and plastic-encapsulated chips appears.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.264-264
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• 2020

최근 기후변화로 우리나라는 과거에 비해 태풍이나 국지성 집중호우 및 가뭄 등 극심한 수문현상이 빈번하게 발생하고 그 피해가 더욱 커지고 있는 추세이다. 특히 우리나라의 경우 산지가 많으며 대부분의 하천이 유역면적이 작고 유로연장이 짧아 단시간에 유출이 발생하며 수문학적 특성이 연중 큰 편차를 보이고 있다. 이러한 이상기후에 따른 수문현상 파악 및 피해 경감을 위해 신뢰성 있는 수문자료는 매우 중요하다. 따라서 수문자료에 대한 품질관리는 필수적이지만 자료 결측 및 오측에 대한 신뢰성 높은 품질관리가 이뤄지지 못하고 있는 실정이다. 현재 수위자료의 결측이 발생한 경우 해당 관측소의 수위 자료를 사용해 선형보간 및 운형자법으로 수정하거나 상·하류 관측소의 관계를 이용하여 회귀분석을 통해 자료 결측의 수정 및 보완을 수행하는 등 담당자의 주관적 판단에 의존하고 있다. 본 논문에서는 신뢰성 높은 수문자료의 결측치 보완 및 예측을 위한 방안을 제시하고자 상류의 관측소의 수문자료를 이용한 하류의 단시간 수문 자료예측에 관한 연구를 수행하였다. 이를 위해 자료지향형 모델인 적응형 뉴로-퍼지 기법(Adaptive Network-based Fuzzy Inference System, ANFIS)을 이용한 모형을 적용하였다. 기존의 연구에서 가장 일반적으로 사용되는 물리적 모형은 수문자료를 활용하여 수위 및 유출을 산정함에 있어 매개변수의 결정이 어렵고 많은 오차들을 내포하고 있다. 본 연구에서 사용한 ANFIS는 입력자료와 출력자료만을 고려하여 구축할 수 있기 때문에 자료 수집단계에서 유역의 물리적 자료 및 지형 자료와 같은 방대한 양의 자료 수집이 필요가 없다. 이후 모형이 구축이 된다면 입·출력 자료만을 이용하여 신뢰성 높은 결과를 획득할 수 있지만 입력 자료의 품질에 따라 결과가 좌우되기 때문에 자료의 구성이 매우 중요하다. 본 연구에서는 ANFIS를 통해 무주남대천 유역의 무주군(여의교) 관측소의 수위자료를 입력자료를 사용하여 하류에 위치한 무주군(취수장) 관측소의 수문자료의 결측 보완 및 예측하는 모형을 구축하고 모형의 구조 변화를 통해 가장 정확도 높은 모형을 결정하였다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.8 no.4
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• pp.225-233
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• 1975

Morphological changes of early post-larval and young stages of Chasmichthys dolichognathus HILGEnDORF (Family Gobiidae) have been studied based on the samples of 953 individuals collected in June 1968, July 1969 and July 1971. Particular emphasis was paid on the development of fin rays, chromatophore patterns and ventral fins. The primordial fin rays of the first dorsal fin appear in the post-larvae of around 8.0 mm in total length, and dorsal fin fully develops in the larvae of around 9.2 mm. In the early young stages of 17.0 mm in total length fin rays have completely developed. According to chromatophore patterns the larvae are grouped into three successive groups. The larvae at the early stages of 6.3-14.2 mm have melanophores on the whole dorsal surface, the posterior ventro-lateral part of the tail and the basal part of the caudal fin. In the later larval stages of 17.0-24.4 mm a group of melanophores are added on medio-lateral part of the tail. These melanophores extend anteriorly and eventually cover the medio-lateral part of the whole body. In the early young stages of 97.2-34.8 mm the chromatophores cover the whole body surface in cloudy and H-shaped patterns. The chromatophore patterns of this stage are distinctive as generic characters of the fish. Fin membranes of the ventral fin appear in the post-larval stage (ca. 7.4 mm), and the primordial fin rays develop in the late post-larval stages (ca. 14.2 mm). The fin rays develop into a complete sucker in the young fish stage of around 30.0 mm in total length.

• Horticultural Science & Technology
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• v.33 no.1
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• pp.55-60
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• 2015

Skin blackening is a serious postharvest disorder occurring in 'Fuyu' persimmon fruits (Diospyros kaki, 'Fuyu'). Phenolic content, polyphenol oxidase (PPO) and peroxidase (POD) activity, and lipid saturation were investigated in skin tissue of 'Fuyu' fruits. The phenolic compounds were accumulated unevenly on fruit skin depending on sunlight exposure, i.e., the most accumulation on sunny side and the least on the opposite, shaded side. The fruits harvested from shaded branches inside the canopy showed relatively even distribution of phenolic compounds in the skin. The activity distribution of PPO and POD were also uneven but only in fruits suffering f rom skin b lackening disorder, w ith the h ighest and the lowest a ctivity of PPO and P OD, respectively, in the blackened area of the fruit. When the sunny, southern sides of fruits were marked at harvesting time and fruits were stored at low temperature, a round black spot, as a symptom of skin blackening disorder, developed during storage exactly on the marked region. In addition, the sunny side of fruit showed higher lipid saturation, thus indicating adaptation to high temperature caused by the sunlight. These results suggest that the skin blackening disorder of 'Fuyu' fruits can be considered as a kind of chilling injury symptom that develops on the high-temperature-acclimated skin tissue of sunlight-exposed fruits when they are later exposed to low temperature.

• Journal of the Korean earth science society
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• v.43 no.2
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• pp.239-252
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• 2022

Quality control methods for the first G-band vapor radiometer (GVR) mounted on a weather aircraft in Korea were developed using the GVR Precipitable Water Vapor (PWV). The aircraft attitude information (degree of pitch and roll) was applied to quality control to select the shortest vertical path of the GVR beam. In addition, quality control was applied to remove a GVR PWV ≥20 mm. It was found that the difference between the warm load average power and sky load average power converged to near 0 when the GVR PWV increased to 20 mm or higher. This could be due to the high brightness temperature of the substratus and mesoclouds, which was confirmed by the Communication, Ocean and Meteorological Satellite (COMS) data (cloud type, cloud top height, and cloud amount), cloud combination probe (CCP), and precipitation imaging probe (PIP). The GVR PWV before and after the application of quality control on a cloudy day was quantitatively compared with that of a local data assimilation and prediction system (LDAPS). The Root Mean Square Difference (RMSD) decreased from 2.9 to 1.8 mm and the RMSD with Korea Local Analysis and Precipitation System (KLAPS) decreased from 5.4 to 4.3 mm, showing improved accuracy. In addition, the quality control effectiveness of GVR PWV suggested in this study was verified through comparison with the COMS PWV by using the GVR PWV applied with quality control and the dropsonde PWV.