Earticle

국내의 건설 산업의 경우 시공을 중심으로 하는 프로젝트관리를 수행하는 반면에 시공품질과 관계를 지닌 설계품질에 대한 관리는 미흡한 실정이다. 따라서 본 연구에서는 시설물별로 설계결함 및 안전취약요소를 파악하고, 설계결함의 발생요인을 분석하여 시설물 설계결함의 최소화를 위한 방법론을 고찰하는 것을 목적으로 수행되었다. 이러한 목적을 달성하기 위해 7개 시설물(교량, 터널, 주상복합, 아파트, 스포츠시설, 오피스텔, 백화점)을 대상으로 설계결함의 분류체계 및 생산조직 간 의사결정의 문제점을 분석하였다. 이를 기반으로 중점관리 시설물의 균열을 예방하기 위한 점검항목을 도출하였으며, 설계결함을 저감하기 위해 생산조직의 협업 방법론을 고찰하고, 유지관리 과정에서의 점검 방안을 제시하였다.

In the case of the domestic construction industry, the project management centering on the construction is carried out, but the management of the design quality with relation to the construction quality is insufficient. Therefore, the purpose of this study is to grasp the design defect and safety vulnerable factor for each facilities, and to consider the methodology for minimizing design defect of the facilities by analyzing occurrence cause of design defect. To achieve this purpose, we analyzed the classification system of design defect and the problems of decision making of production organization aimed at facilities(bridge, tunnel, residential complex, apartment, sport facilities, officetel, department store). Based on this study, we deducted the inspection items to prevent crack for each priority management facilities, and suggest the plans of inspection in maintenance phase by considering the methodology for collaboration of production organization in order to reduce design defect.

국내에서 제조물책임법의 입법논의가 본격적으로 진행되던 시기에는 학자들의 활발한 입법논의만큼이나 기업들의 반대의견의 제시도 만만치 않았다. 그 당시 기업들은 제조물책임법이 제정되면 대부분의 제조업체들이 파산할 것이라는 우려를 표출하였다. 법 시행 후 약 15년이 지난 지금에는 기업들의 파산이 문제로 되는 것이 아니라, 까다로운 입증책임으로 인하여 피해 소비자들이 제조물책임법에 의한 구제를 충분히 받지 못하는 것이 우려가 되고 있는 상황이라고 할 수 있다. 특히 현대에 있어서 입증책임이 문제가 되는 결함의 유형은 설계상 결함에 집중되고 있다. 소비자가 설계상 결함을 입증하기 위해서는 결함판단기준을 충족하여야 하는데, 현재에는 위험효용기준이 주된 결함판단기준으로 자리 잡고 있다. 그러나, 위험효용기준에 의하여 결함을 입증하기 위해서는 제조물의 위험과 사회적 효용성을 비교하여 위험성이 효용성을 초과한다는 점 및 합리적 대체설계의 가능성이 존재한다는 점을 소비자가 제시하여야 하므로 제조물에 적용되는 기술의 고도화와 비례하여 결함의 입증은 점점 더 어려워지고 있다. 이를 두고 미국에서는 무과실책임에 가까운 소비자기대기준에서 위험효용기준으로의 수정은 과실책임주의로의 회귀라는 비판도 제기되고 있다. 특히, 일반적으로 널리 사용되는 제품 중에서도 그 특성상 본질적으로 위험한 경우나 첨단 과학기술이 내재된 제조물의 경우에는 일반인인 소비자가 위험성이 있는 제조물의 위험과 효용을 분석하고 효용성이 위험성을 초과할 수 있는 합리적 대체설계를 제시하여 손해배상을 받은 것은 거의 불가능에 가까워지고 있다. 이처럼 현실적인 결합입증의 한계에 대한 반동으로 미국에서는 설계상 결함판단기준으로서의 새로운 이론으로 제품분류책임(products category liability)이 제기되고 있다. 이 논문에서는 주로 미국의 이론과 판례를 통하여 제품분류책임의 내용과 적용상의 문제점을 검토하고, 최근 제조물책임법의 개정을 통하여 결함의 추정에 관한 조문을 신설한 이후에도 설계상 결함의 요건으로 인정되고 있는 피해자에 의한 합리적 대체설계의 제시 가능성을 여전히 요구할 것인가와 관련한 입법적 논의도 필요할 것으로 생각된다.

In the product liability, it is significant that the strict liability has been adopted as an exception of the negligence liability for easy compensation of consumers’damage. However, consumers have to prove the existence of defect in order to get compensation even under the strict liability system. To prove the design defect, consumers must satisfy with the criteria of defects. According to the consumer expectation test, the defect can be judged whether there is a risk that a reasonable consumer can not expect or not. However, there would be no defect if the risk of the product would be clear and consumers could recognize in advance. Therefore, the risk-utility test has become the main criterion for defect. Even though under the risk-utility test, in order to prove the defect under the risk-utility test, consumers must prove that there is a risk that exceeds the social utilities of the products and that a reasonable alternative design exists additionally. Proving defects in proportion to technological advancement is becoming increasingly difficult. It has also been criticized that the revision from the consumer expectation test to the risk-utility test in the Restatement (third) of Tort is a regression to the principle of negligence liability. In particular, in the case of inherently dangerous products or products with advanced technology, it has been increasingly difficult for consumers to get compensation by suggesting the reasonable alternative design. As the result, the product category liability theory has emerged as an alternative for the criterion for defect in the United States. In this paper, I researched the contents and the problems of product category liability through the theories and precedents in the United States, and examined the possibility of introducing it in Korea.

자율주행자동차 등의 첨단기술을 기반으로 하는 제조물의 결함에 대해서는 제조상 결함보다는 설계상 결함이 주로 문제가 될 것으로 예상되고, 이에 대해서 제조자가 개발위험의 항변을 주장하는 경우에 제조 당시의 최고 수준의 기술을 기준으로 개발위험의 항변 여부를 판단하여야 한다. 개발위험의 항변이 인정되는 경우에도 표시상의 결함 여부를 추가적으로 판단하는 방법에 의하여 최종적으로 제조물책임 여부를 결정하게 된다. 따라서 첨단과학기술제품에 대한 제조물책임은 주로 설계상 결함에서부터 시작된다는 점에서 설계상 결함의 판단기준이 매우 중요한 의미를 갖는다. 그러나 설계상 결함의 판단기준으로 소비자기대기준이 폐기되고 위험효용기준으로 전환됨으로써 피해자는 합리적 대체설계를 제시하여야만 결함을 주장할 수 있게 되었다. 특히 자율주행자동차와 같은 제품은 각종의 첨단기술이 탑재된 부품과 인공지능의 역할을 수행하는 소프트웨어 등이 결합되어 있다는 점에서 피해자가 합리적 대체설계를 제시할 수 있는 가능성은 매우 낮은 영역이라고 할 수 있다. 제품에 내재하는 위험과 효용을 비교하는 위험효용기준에 의하여 설계상 결함을 판단하는 경우에는 자동차라는 제품분류는 위험보다 효용이 크다는 점에서 결함이 존재하지 않는 것으로 평가될 수 있다. 그러나 실제로 자동차라는 제품군에 있어서 결함의 존재 여부는 자동차를 더 안전하게 제조할 수 있는지의 여부에 달려 있다. 자율주행자동차에 대한 결함판단도 이와 유사할 것이다. 자율주행자동차라고 하는 제품분류가 전체적으로 사회적 효용이 위험을 초과하는 것으로 평가되거나 반대로 위험이 사회적 효용을 초과하는 것으로 평가되는 경우, 제품분류책임에 의하면 자율주행자동차라는 제품군 전체에 대하여 항상 결함의 존재가 부정되거나 또는 항상 결함의 존재가 인정되는 결과가 도출될 수 있다는 문제도 있다. 한편 제품분류책임의 경우에는 그 분류단계에 따라 자율주행자동차군이 하나의 제품분류단계에 해당할 수도 있고, 자율주행자동차에 탑재되는 보편적인 부품군과 소프트웨어군도 세부분류단계에 해당할 수 있을 것이다. 따라서 자율주행자동차군이 제품분류책임에 의하여 결함이 인정되지 않는 경우에도 사고의 원인이 되는 각 부품군에 대한 제품분류책임을 적용하는 방안도 고려될 수 있다. 이러한 점에서 합리적 대체설계에 의한 위험효용기준을 보완할 수 있는 결함판단기준으로 제품분류책임의 적용에 대한 검토가 필요할 것으로 생각된다. 아울러 최근의 가습기살균제 사건의 경우에도 PHMG가 첨가된 살생물제에 대하여 제품분류책임을 적용함으로써 합리적 대체설계 여부와 관계없이 설계상 결함을 판단할 수 있는 기준으로 작용할 수 있을 것으로 생각된다.

About the defects of the products that are based on state-of-the-art technologies such as an autonomous car, a design defect is mainly predicted to be an issue. When a manufacturer protests a state-of-the-art defence against a design defect, it must be decided not by the average level of technology but by the highest level of technology. Even after the manufacturer's defence is admitted, he can be immune from products liability without proof of a warning defect. By switching a criterion of a design defect from consumer expectation test to risk-utility-test, a plaintiff must protest products liability with a reasonable alternative design. But it would be very difficult for a plaintiff to suggest a reasonable alternative design in the field of state-of-the-art technologies such as a autonomous car. When we judge a design defect by the risk-utility-test, it can be estimated that cars don't have any defect because the product category as cars have more utility and less risk. Judgement of defects on autonomous cars might be similar to cars. but if the result of defect evaluation about product category as autonomous cars shows that the risk always exceed the social utility or vise versa, the problem that all the product category as autonomous cars are always acknowledged defective products or vise versa can be raised. Meanwhile, in the case of product category liability, autonomous cars can belong to a big category or common auto parts and softwares that are equipped on autonomous cars can belong to sub-category by the product category liability. Therefore, unless autonomous cars don't have any defect according to the product category liability, it can be considered that each sub-category of auto parts that can cause the risk. For this reason, we need to review the applicability of product category liability as the standard of judgment that can supplement the risk-utility-test based on reasonable alternative design. If the product category liability isn't acknowledged to autonomous cars, I think a defect can be acknowledged to hide risks. As the product category liability works as the standard of design defects, the possibility of reasonable alternative design must be existed to a hide risk by the product design. But a warning defect can be acknowledged to a hide risk. In the case of tobacco lawsuit, even though the design defect based on the product category liability may not be acknowledged, a warning defect to hide risks of tobacco can be acknowledged. But I think the warning defect to generally opened risks will not be acknowledged. In the case of latest humidifier germicide cases added polyhexamethylene guanidine(PHMG) manufactured by Oxy Korea and other companies in Korea, products category liability can work as a criterion of design defect in products liability regardless of reasonable alternative design by applying products category liability to biocidal products added PHMG.

공동주택 건축기계설비 하자는 시공상 발생되는 하자와 설계시에 발생되는 하자로 분류되며 보통 10~15% 정도가 설계하자로 분류된다. 시공상 발생되는 하자는 일반적인 방법으로 수정에 의해서 비교적 간단히 해 결될 수 있는 하자가 대부분으로 판단된다. 그러나 설계하자의 경우 발생빈도는 낮지만 하자가 발생되면 시 스템적으로 큰 문제로 연관되므로 건축물에 미치는 영향과 재시공상의 경제적 손실이 크므로 하자발생을 미 연에 방지하고자 설계단계부터 하자 발생 원인을 분석하여, 건축설비 하자에 대한 근본적인 개선방안을 모 색하고자 하는 것이 본 연구의 목적이다. 따라서 본 연구에서는 근본적인 설계하자 예방을 위해서 기존 문헌 고찰을 통해서 설계하자를 분석하였고, 실사례조사에서 공동주택 건축기계설비하자에서 설계하자를 분류하 여 가장 발생빈도가 많은 11개 항목으로 설계자를 대상으로 하자에 대한 인식, 하자발생원인, 하자예방 개선 방안 등 설문을 실시하였다. 하자발생의 주원인으로 납품시간 부족이 75명 중 39명(52%), 전문지식부족 및 경험부족이 15명(20%) 등이었고, 하자 개선방안으로는 충분한 설계시간 확보가 75명 중 40명(53%), 타 공정 과 긴밀한 협의가 15명(20%) 등이었다. 공동주택 건축기계설비 설계하자 개선방안을 분석한 결과 공동주택 건축기계 설계업의 구조적, 환경적으로 문제점들이 내재되어 있는 것으로 파악되었다. 문제점으로는 설계자들의 하자에 대한 인식의 문제, 영세한 설계업계의 구조적 문제, 기계설비 전문교육기관 부재의 환경적 문제점으로 함축되었다. 위의 문제점들을 개선하는 것이 설계하자를 줄 일수 있는 근본적인 방법으로 제도적 개선방안을 제시하면 다음과 같다. 첫째, 정확한 설계 매뉴얼 및 지침서의 정립 둘째, 분리발주를 의무화하여 적절한 설계비 투입 셋째, 전문교육을 받을 수 있는 교육의 장이 마련

Defects of the mechanical system in multi-family residential building can be classified into two categories: construction defect and design defect which accounts for 10-15percent. The construction defect can easily be resolved by simple or moderate repair work. However, even though the risk of incidence is low, the design defect, in general, result in the systematic problems, which influences the building and causes the economic losses of re-construction. Analyzing the causes of defects from design phase, this study aimed to find out the measures for fundamental improvement of the mechanical system defect of building and to prevent the occurrence of defects. The design defect was first analyzed through literature review and classified by case studies. Using a questionnaire with 11 items of high frequency incidences, the survey was administered to mechanical system designers asking their opinions on recognition, causes and improvement of defects and so on..The main reasons of defect occurrence were lack of time(52%, 39 of 75 responses) and specialized knowledge and experience(20%, 15 of 75). The measures for improvement that the respondents answered were having enough time(53%, 40 of 75) and close collaboration in all divisions throughout the entire construction processes(20%, 15 of 75). Results of the present study revealed that there were inherent problems with business environment and structure of building mechanical system design. This study suggests the institutional measures for improvement in order to reduce the design defect may include the establishment of accurate design manual and guideline, investment in proper design with mandatory separate orders and development of specialized training program and education venue.

This paper proposes an automatic defect classification (ADC) system to detect and classify bare wafer edge defects that occur during the extreme wafer thinning process required for advanced chip stacking technologies such as TSV and HBM. The proposed system combines a convolutional neural network (ResNet) with traditional image processing techniques (OpenCV-based frequency domain filtering) to effectively classify and visualize wafer edge defects. Experimental results demonstrate that the system achieves high accuracy in defect classification and detection, providing an efficient solution to prevent wafer damage and yield reduction.

Lithium-ion batteries (LIBs) are widely used in transportation and energy-storage system; however, their increasing deployment raises concerns about thermal runaway caused by internal defects. The aim of the current study is to optimize a radiography instrument to detect internal defects in LIB at the module level. Using Monte Carlo simulation, a commercial cylindrical 18650 LIB module and a CsI(Tl) detector were modeled. To enhance the performance of the radiography instrument, parameters such as X-ray energy, filter material and thickness, pixel size, and magnification were optimized. Quantitative metrics, including signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and detectability index, were used to evaluate image quality. Optimal conditions were determined to be 150 keV X-ray energy, 1.6-mm Sn filtration, 85 ㎛ pixel size, and 2.1 magnification. Under these conditions, crack and delamination defects were distinguishable at sizes of 0.18 and 6.6 mm, respectively. Future work involves fabricating and experimentally validating the prototype instrument under actual LIB inspection condition.

Thermoelectric is a key technology for energy harvesting and solid-state cooling by direct thermal-to-electric energy conversion (or vice versa); however, the relatively low efficiency has limited thermoelectric systems to niche applications such as space power generation and small-scale or high-density cooling. To expand into larger scale power generation and cooling applications such as ATEG (automotive thermoelectric generators) and HVAC (heating, ventilation, and air conditioning), high-performance bulk thermoelectric materials and their low-cost processing are essential prerequisites. Recently, the performance of commercial thermoelectric materials including $Bi_2Te_3$-, PbTe-, skutterudite-, and half-Heusler-based compounds has been significantly improved through non-equilibrium processing technologies for defect engineering. This review summarizes material design approaches for the formation of multi-dimensional and multi-scale defect structures that can be used to manipulate both the electronic and thermal transport properties, and our recent progress in the synthesis of conventional thermoelectric materials with defect structures is described.

Background Myelomeningocele is a frequently seen condition at tertiary care hospitals. Its treatment involves a variety of plastic reconstructive techniques. Herein, we present a series of myelomeningocele patients treated using keystone flaps. Methods We gathered information regarding soft tissue reconstruction and the use of bilateral keystone flaps to treat myelomeningocele patients. We obtained data from clinical records and recorded the demographic characteristics of mothers and children with the condition. The size, level of defect, and complications detected during the follow-up were analyzed. Results A series of seven patients who underwent bilateral keystone flaps for myelomeningocele closure was analyzed. There were no cases of midline or major dehiscence, flap loss, necrosis, surgical site infections, or cerebrospinal fluid leakage. No revision procedures were performed. Minor complications included one case with minimal seroma and three cases with areas of peripheral dehiscence that healed easily using conventional measures. Conclusions The use of keystone flaps is an adequate option for closure of dorsal midline soft tissue defects related to myelomeningocele. This technique offers predictable results with an acceptable spectrum of complications. Robust blood flow can be predicted based upon anatomical knowledge.

BACKGROUND: Perimembranous ventricular septal defects (VSDs) has proximate relation to the aortic and tricuspid valves as well as the conduction tissues. Transcatheter closure utilizes various off-label device designs. METHODS: Perimembranous VSD without aortic margin were classified as group A, with thick aortic margin as group B, with membranous septal aneurysm as group C and defects restricted by tricuspid valve attachments as group D. The proposed ideal design was asymmetric device in group A; duct occluder I (ADOI) and muscular ventricular septal occluder (MVSO) in group B; thin profile duct occluder II (ADOII) in group C and ADOI in group D. Device was 0?2 mm larger than the defect. RESULTS: Eighty patients with VSD measuring 6.83 ± 2.87mm underwent successful closure. Device was retrieved before release in one group A and one group C patient due to aortic regurgitation. Asymmetric device was used in 16 group A defects. Among group B defects, ADOI was used in 5, ADOII in 5, MVSO in one and asymmetric device in 3. Group C defects were closed with ADOI in 7, ADOII in 10 and asymmetric device in 3. Three patients with multiple exits had 2 ADOII devices. Group D defects were closed using ADOI in 20 and ADOII in 10 patients. There was no late aortic regurgitation or heart block on a follow-up exceeding 7 years. CONCLUSIONS: This echocardiographic classification helps device selection in every single patient. While asymmetric device is uniquely suited for group A defects, different designs are appropriate in the other groups.

Objectives: The aim of this study was to describe a simple, convenient, and reliable new technique using local full-thickness skin graft (FTSG) for skin coverage of a donor-site defect of the radial forearm free flap (RFFF). Patients and Methods: Between April 2016 and April 2021, five patients with oral squamous cell carcinoma underwent mass resection combined with RFFF reconstruction. After RFFF harvesting, donor-site defects were restored by proportional local FTSG. Results: The donor-site defects ranged in size from 24 to 41.25 cm², with a mean of 33.05 cm². Good or acceptable esthetic outcomes were obtained in all five patients. There was no dehiscence, skin necrosis, wound infection, or severe scarring at the graft site through the end of the postoperative follow-up period, and no patient had any specific functional complaint. Conclusion: The proportional local FTSG showed promising results for skin coverage of the donor-site defect of the RFFF. This technique could decrease the need for skin grafts from other sites.

Objectives: The aim of this study was to describe a simple, convenient, and reliable new technique using local full-thickness skin graft (FTSG) for skin coverage of a donor-site defect of the radial forearm free flap (RFFF). Patients and Methods: Between April 2016 and April 2021, five patients with oral squamous cell carcinoma underwent mass resection combined with RFFF reconstruction. After RFFF harvesting, donor-site defects were restored by proportional local FTSG. Results: The donor-site defects ranged in size from 24 to 41.25 cm2, with a mean of 33.05 cm2. Good or acceptable esthetic outcomes were obtained in all five patients. There was no dehiscence, skin necrosis, wound infection, or severe scarring at the graft site through the end of the postoperative follow-up period, and no patient had any specific functional complaint. Conclusion: The proportional local FTSG showed promising results for skin coverage of the donor-site defect of the RFFF. This technique could de-crease the need for skin grafts from other sites.

전자 산업의 발달과 함께 많은 전자 제어 장치가 차량 내부에 탑재됨에 따라 차량의 기능을 검증하는 것은 더더욱 어려워지고 있다. 차량의 기능 오작동은 인명손실의 우려가 있기 때문에 차량에 있어서 신뢰성은 무엇보다 중요하게 고려되어야 한다. 본 논문에서는 차량의 신뢰성 향상을 위한 CAN 통신 기반의 고장 진단 플랫폼을 제안한다. 양산 이후에도 독립적인 테스트 경로를 통한 구조적 테스트를 실시함으로써 차량의 신뢰성은 크게 증가할 것이다. 또한, 별도의 테스트 핀이 필요하지 않기 때문에 테스트 비용을 절감할 수 있다.

To verify the function of vehicle is becoming more and more difficult because many electronic control units have been embedded in vehicle with development of electronics industry. The reliability of vehicle should be considered above all important because malfunction of vehicle can cause damage of human life. In this paper, defect diagnosis platform based on CAN network is proposed to improve the reliability of vehicle. Reliability of vehicle is significantly increased by adopting the structural test via dedicated test path after manufacturing. Besides, the test cost is reduced because additional test pins are not required.

사물인터넷을 기반으로 실시간으로 소화기 주변의 상태와 화재 발생 여부, 소화기의 상태를 확인할 수 있는 웹 시스템과 화재 알림을 받을 수 있는 애플리케이션을 구현한다. 해당 시스템의 목표를 명확하게 정하고 구조를 상세히 정의함으로써 개발 도중 일어나는 오류를 최소화한다. 또한, 스마트소화기에 대한 요구분석과 설계, 구현 단계에서 제품 결함을 찾아내고 그 원인을 분석하여 결함을 줄이는 방법을 제안한다. 제안하는 연구를 통해 IoT 기반의 스마트 소화기에 대해 결함관리 신뢰성을 확보할 수 있다.

Based on the Internet of Things, a web system that can check the condition around the fire extinguisher, whether a fire has occurred, and an application that can receive fire notifications in real time is implemented. Minimize errors that occur during development by using software engineering to clarify the goals of the system and define the structure in detail. In addition, for IoT-based fire extinguishers, a method of reducing defects by finding product defects in the demand analysis, design, and implementation stages and analyzing the cause thereof is proposed. Through the proposed research, it is possible to secure the reliability of defect management for IoT-based smart fire extinguisher.

Flow defect of a piston-pin for automobile parts is investigated in this study. In cold forging of piston-pin Lapping defect a kind of flow defect appears by the dead metal zone. This appearance evidently happens in products with a thin piercing thickness for the dimension accuracy and the decrease of material loss. The best method that can prevent flow defect is removing dead metal zone. The finite element simulations are applied to analyze the flow defect. This study proposed processes for preventing flow defect by removing dead metal zone. Then the results are compared with the experiments for verification. These FE simulation results are in good agreement with the experimental ones.

본 논문에서는 패턴인식을 이용한 의류의 결함을 자동으로 탐색하는 시스템을 설계하였다. 이는 히스토그램을 기반으로 하여 영상의 특징을 추출하고 템플릿 매칭을 이용해서 패턴을 추적하도록 하였스며, 또한, SSIM(Structural Similarity) Index를 통해 추적된 패턴과 원 패턴의 유사도를 HVS(Human Vision System)을 기준으로 하여 결함을 판별할수 있도록 하였다.

본 논문에서는 패턴인식을 이용한 의류의 결함을 자동으로 탐색하는 시스템을 설계하였다. 이는 히스토그램을 기반으로 하여 영상의 특징을 추출하고 템플릿 매칭을 이용해서 패턴을 추적하도록 하였스며, 또한, SSIM(Structural Similarity) Index를 통해 추적된 패턴과 원 패턴의 유사도를 HVS(Human Vision System)을 기준으로 하여 결함을 판별할수 있도록 하였다.

본 연구에서는 웨이퍼의 자동광학검사를 위한 결점 검출 비전 시스템을 개발하였다. 성공적 결점 검출을 위해 몇 가지 이진화 방법을 비교하였고, bimodal과 unimodal 분포에 모두 좋은 결과를 나타낸 개선된 Otsu 방법을 선택하였다. 빠르고 정확한 임계값 계산을 위해 ROI 추출기능을 개발하였으며 최종적으로 웨이퍼의 검출 패턴은 정의된 기준에 따라 영상 분류되었고 성능평가를 위해 14개 이상의 웨이퍼 영상으로 테스트하였다.

This document illustrates the relationship between the wire rod wrinkle defect and the roll caliber design. The wrinkle defect is caused by the incongruent rolling conditions of the roll caliber design, the roll adjustment, and the extracting temperature. In this document, we restrict the study scope to the roll caliber design's effect on wrinkle defect at the base of real condition of the No.2 Wire Rod mill, POSCO. There has been wrinkle defect problem in the No.2 Wire Rod Mill, POSCO for many years. The engineers of the wire rod mill have been making efforts to solve the problem. As one of the efforts, we take the samples of the wire rod in the each stands of the 2'nd wire rod mill and then analyze the samples. Through the analysis, we find out the problem of the roll caliber design. So, we suggest the roll caliber design method to be more effective to weaken the wrinkle defect.